Introduction
The GSOD or Global Surface Summary of the Day (GSOD) data provided by the US National Centers for Environmental Information (NCEI) are a valuable source of weather data with global coverage. However, the data files are cumbersome and difficult to work with. {GSODR} aims to make it easy to find, transfer and format the data you need for use in analysis and provides six main functions for facilitating this:
get_GSOD()- this function queries and transfers files from the NCEI’s web server, reformats them and returns a data frame.reformat_GSOD()- this function takes individual station files from the local disk and re-formats them returning a data frame.nearest_stations()- this function returns adata.tableof stations with their metadata and the distance in which they fall from the given radius (kilometres) of a point given as latitude and longitude in order from nearest to farthest.get_inventory()- this function downloads the latest station inventory information from the NCEI’s server and returns the header information about the latest version as a message in the console and a tidy data frame of the stations’ inventory for each month that data are reported.get_history()- this function downloads the latest version of the isd-history.csv file from the NCEI’s server and returns a {data.table} of the information for each station that is available. A version of this file is distributed with {GSODR} internally and can be updated withupdate_internal_isd_history().get_updates()- this function downloads the changelog for the GSOD data from the NCEI’s server and reorders it by the most recent changes first.update_internal_isd_history()- this function downloads the latest station list from the NCEI’s server updates the package’s internal database of stations and their metadata. Not recommended for normal use.
When reformatting data either with get_GSOD() or
reformat_GSOD(), all units are converted from United States
Customary System (USCS) to International System of Units (SI),
e.g., inches to millimetres and Fahrenheit to Celsius. Data in
the R session summarise each year by station, which also includes vapour
pressure and relative humidity elements calculated from existing data in
GSOD.
For more information see the description of the data provided by NCEI, https://www.ncei.noaa.gov/data/global-summary-of-the-day/doc/readme.txt.
Using get_GSOD()
Find Stations in or near Toowoomba, Queensland, Australia
{GSODR} provides lists of weather station locations and elevation values. It’s easy to find all stations in Australia.
library("GSODR")
load(system.file("extdata", "isd_history.rda", package = "GSODR"))
# create data.frame for Australia only
Oz <- subset(isd_history, COUNTRY_NAME == "AUSTRALIA")
Oz## Key: <STNID>
## STNID NAME LAT LON
## <char> <char> <num> <num>
## 1: 695023-99999 HORN ISLAND (HID) -10.583 142.300
## 2: 749430-99999 AIDELAIDE RIVER SE -13.300 131.133
## 3: 749432-99999 BATCHELOR FIELD AUSTRALIA -13.049 131.066
## 4: 749438-99999 IRON RANGE AUSTRALIA -12.700 143.300
## 5: 749439-99999 MAREEBA AS/HOEVETT FIELD -17.050 145.400
## ---
## 1415: 959890-99999 BICHENO (COUNCIL DEPOT) -41.867 148.300
## 1416: 959950-99999 LORD HOWE ISLAND WINDY POINT -31.533 159.067
## 1417: 959970-99999 HEARD ISLAND (ATLAS COVE) -53.017 73.400
## 1418: 996600-99999 ENVIRONM BUOY 55011 -40.800 144.300
## 1419: 999999-82101 NORTHWEST CAPE -22.333 114.050
## ELEV(M) CTRY STATE BEGIN END COUNTRY_NAME
## <num> <char> <char> <int> <int> <char>
## 1: NA AS 19420804 20030816 AUSTRALIA
## 2: 131.0 AS 19430228 19440821 AUSTRALIA
## 3: 107.0 AS 19421231 19430610 AUSTRALIA
## 4: 18.0 AS 19420917 19440930 AUSTRALIA
## 5: 443.0 AS 19420630 19440630 AUSTRALIA
## ---
## 1415: 11.0 AS 19650101 20240908 AUSTRALIA
## 1416: 4.0 AS 20120920 20240909 AUSTRALIA
## 1417: 4.0 AS 19980301 20121220 AUSTRALIA
## 1418: 0.0 AS 19930221 19970403 AUSTRALIA
## 1419: 38.1 AS 19680305 19680430 AUSTRALIA
## ISO2C ISO3C
## <char> <char>
## 1: AU AUS
## 2: AU AUS
## 3: AU AUS
## 4: AU AUS
## 5: AU AUS
## ---
## 1415: AU AUS
## 1416: AU AUS
## 1417: AU AUS
## 1418: AU AUS
## 1419: AU AUS## Key: <STNID>
## STNID NAME LAT LON ELEV(M) CTRY
## <char> <char> <num> <num> <num> <char>
## 1: 945510-99999 TOOWOOMBA -27.583 151.933 676 AS
## 2: 955510-99999 TOOWOOMBA AIRPORT -27.550 151.917 642 AS
## STATE BEGIN END COUNTRY_NAME ISO2C ISO3C
## <char> <int> <int> <char> <char> <char>
## 1: 19561231 19971231 AUSTRALIA AU AUS
## 2: 19980301 20240909 AUSTRALIA AU AUSDownload a Single Station and Year Using get_GSOD()
Now that we’ve seen where the reporting stations are located, we can
download weather data from the station Toowoomba, Queensland, Australia
for 2010 by using the STNID in the station parameter of
get_GSOD().
## Classes 'data.table' and 'data.frame': 365 obs. of 47 variables:
## $ STNID : chr "955510-99999" "955510-99999" "955510-99999" "955510-99999" ...
## $ NAME : chr "TOOWOOMBA AIRPORT" "TOOWOOMBA AIRPORT" "TOOWOOMBA AIRPORT" "TOOWOOMBA AIRPORT" ...
## $ CTRY : chr "AS" "AS" "AS" "AS" ...
## $ COUNTRY_NAME : chr "AUSTRALIA" "AUSTRALIA" "AUSTRALIA" "AUSTRALIA" ...
## $ ISO2C : chr "AU" "AU" "AU" "AU" ...
## $ ISO3C : chr "AUS" "AUS" "AUS" "AUS" ...
## $ STATE : chr "" "" "" "" ...
## $ LATITUDE : num -27.6 -27.6 -27.6 -27.6 -27.6 ...
## $ LONGITUDE : num 152 152 152 152 152 ...
## $ ELEVATION : num 642 642 642 642 642 642 642 642 642 642 ...
## $ BEGIN : int 19980301 19980301 19980301 19980301 19980301 19980301 19980301 19980301 19980301 19980301 ...
## $ END : int 20240909 20240909 20240909 20240909 20240909 20240909 20240909 20240909 20240909 20240909 ...
## $ YEARMODA : Date, format: "2010-01-01" ...
## $ YEAR : int 2010 2010 2010 2010 2010 2010 2010 2010 2010 2010 ...
## $ MONTH : int 1 1 1 1 1 1 1 1 1 1 ...
## $ DAY : int 1 2 3 4 5 6 7 8 9 10 ...
## $ YDAY : int 1 2 3 4 5 6 7 8 9 10 ...
## $ TEMP : num 21.2 23.2 21.4 18.9 20.5 21.9 21.3 20.9 21.9 22.3 ...
## $ TEMP_ATTRIBUTES : int 8 8 8 8 8 8 8 8 8 8 ...
## $ DEWP : num 17.9 19.4 18.9 16.4 16.4 18.7 17.4 17.1 16.2 14.9 ...
## $ DEWP_ATTRIBUTES : int 8 8 8 8 8 8 8 8 8 8 ...
## $ SLP : num 1013 1010 1012 1016 1016 ...
## $ SLP_ATTRIBUTES : int 8 8 8 8 8 8 8 8 8 8 ...
## $ STP : num 942 939 941 944 944 ...
## $ STP_ATTRIBUTES : int 8 8 8 8 8 8 8 8 8 8 ...
## $ VISIB : num NA NA 14.3 23.3 NA NA NA NA NA NA ...
## $ VISIB_ATTRIBUTES: int 0 0 6 4 0 0 0 0 0 0 ...
## $ WDSP : num 4.3 3.7 7.6 8.7 7.5 6.3 7.8 7.5 6.8 6.3 ...
## $ WDSP_ATTRIBUTES : int 8 8 8 8 8 8 8 8 8 8 ...
## $ MXSPD : num 6.7 5.1 10.3 10.3 10.8 7.7 8.7 8.7 8.2 7.2 ...
## $ GUST : num NA NA NA NA NA NA NA NA NA NA ...
## $ MAX : num 25.8 26.5 28.7 24.1 24.6 26.8 26.1 26.5 27.4 28.7 ...
## $ MAX_ATTRIBUTES : chr NA NA NA NA ...
## $ MIN : num 17.8 19.1 19.3 16.9 16.7 17.5 19.1 18.5 17.8 17.7 ...
## $ MIN_ATTRIBUTES : chr NA NA "*" "*" ...
## $ PRCP : num 1.52 0.25 19.81 1.02 0.25 ...
## $ PRCP_ATTRIBUTES : chr "G" "G" "G" "G" ...
## $ SNDP : num NA NA NA NA NA NA NA NA NA NA ...
## $ I_FOG : num 0 0 1 0 0 1 1 0 1 1 ...
## $ I_RAIN_DRIZZLE : num 0 0 1 0 0 0 0 0 0 0 ...
## $ I_SNOW_ICE : num 0 0 0 0 0 0 0 0 0 0 ...
## $ I_HAIL : num 0 0 0 0 0 0 0 0 0 0 ...
## $ I_THUNDER : num 0 0 0 0 0 0 0 0 0 0 ...
## $ I_TORNADO_FUNNEL: num 0 0 0 0 0 0 0 0 0 0 ...
## $ EA : num 2 2.2 2.2 1.9 1.9 2.2 2 1.9 1.8 1.7 ...
## $ ES : num 2.5 2.8 2.5 2.2 2.4 2.6 2.5 2.5 2.6 2.7 ...
## $ RH : num 81.5 79.2 85.7 85.4 77.3 82.1 78.5 78.9 70.1 62.9 ...
## - attr(*, ".internal.selfref")=<externalptr>Using nearest_stations() to Download Multiple Stations at Once
Using the nearest_stations() function, you can find
stations closest to a given point specified by latitude and longitude in
decimal degrees. This can be used to generate a vector to pass along to
get_GSOD() and download the stations of interest.
Warning messages will be generated as not all stations have data for the requested year.
tbar_stations <- nearest_stations(LAT = -27.5598,
LON = 151.9507,
distance = 50)$STNID
tbar <- get_GSOD(years = 2010, station = tbar_stations)## Warning:
## This station, 945510-99999, only provides data for years 1956 to 1997.
## Please send a request that falls within these years.## Warning:
## This station, 949999-00170, only provides data for years 1971 to 1984.
## Please send a request that falls within these years.## Warning:
## This station, 949999-00183, only provides data for years 1983 to 1984.
## Please send a request that falls within these years.
str(tbar)## Classes 'data.table' and 'data.frame': 1095 obs. of 47 variables:
## $ STNID : chr "945520-99999" "945520-99999" "945520-99999" "945520-99999" ...
## $ NAME : chr "OAKEY" "OAKEY" "OAKEY" "OAKEY" ...
## $ CTRY : chr "AS" "AS" "AS" "AS" ...
## $ COUNTRY_NAME : chr "AUSTRALIA" "AUSTRALIA" "AUSTRALIA" "AUSTRALIA" ...
## $ ISO2C : chr "AU" "AU" "AU" "AU" ...
## $ ISO3C : chr "AUS" "AUS" "AUS" "AUS" ...
## $ STATE : chr "" "" "" "" ...
## $ LATITUDE : num -27.4 -27.4 -27.4 -27.4 -27.4 ...
## $ LONGITUDE : num 152 152 152 152 152 ...
## $ ELEVATION : num 407 407 407 407 407 ...
## $ BEGIN : int 19730430 19730430 19730430 19730430 19730430 19730430 19730430 19730430 19730430 19730430 ...
## $ END : int 20240909 20240909 20240909 20240909 20240909 20240909 20240909 20240909 20240909 20240909 ...
## $ YEARMODA : Date, format: "2010-01-01" ...
## $ YEAR : int 2010 2010 2010 2010 2010 2010 2010 2010 2010 2010 ...
## $ MONTH : int 1 1 1 1 1 1 1 1 1 1 ...
## $ DAY : int 1 2 3 4 5 6 7 8 9 10 ...
## $ YDAY : int 1 2 3 4 5 6 7 8 9 10 ...
## $ TEMP : num 23.4 26.2 24.5 21.6 22.6 24.7 24 23.3 24.4 25.1 ...
## $ TEMP_ATTRIBUTES : int 16 16 16 16 16 16 16 16 16 16 ...
## $ DEWP : num 18.4 19.4 19.4 16.8 16.9 18.7 17.1 17.1 15.7 13.6 ...
## $ DEWP_ATTRIBUTES : int 16 16 16 16 16 16 16 16 16 16 ...
## $ SLP : num 1012 1009 1011 1015 1015 ...
## $ SLP_ATTRIBUTES : int 16 16 16 16 16 16 16 16 16 16 ...
## $ STP : num 967 964 966 969 969 ...
## $ STP_ATTRIBUTES : int 16 16 16 16 16 16 16 16 16 16 ...
## $ VISIB : num NA NA NA NA NA NA NA NA NA NA ...
## $ VISIB_ATTRIBUTES: int 0 0 0 0 0 0 0 0 0 0 ...
## $ WDSP : num 4.3 4.1 6.1 7.5 4.4 4.3 5.8 6.2 5.6 4.5 ...
## $ WDSP_ATTRIBUTES : int 16 16 16 16 16 16 16 16 16 16 ...
## $ MXSPD : num 7.2 6.2 8.7 9.8 7.7 6.2 8.2 9.3 7.7 7.2 ...
## $ GUST : num NA NA NA NA NA NA NA NA NA NA ...
## $ MAX : num 28.5 31.2 33.6 27.1 27.8 30.4 30 30.5 31.9 33.2 ...
## $ MAX_ATTRIBUTES : chr NA NA NA NA ...
## $ MIN : num 19.5 20.5 21.3 18.8 18.4 18.6 20.6 18.6 17.2 16.2 ...
## $ MIN_ATTRIBUTES : chr NA NA "*" "*" ...
## $ PRCP : num 0.51 0 3.3 0 0 0 0 0.25 0 0 ...
## $ PRCP_ATTRIBUTES : chr "G" "G" "G" "G" ...
## $ SNDP : num NA NA NA NA NA NA NA NA NA NA ...
## $ I_FOG : num 0 0 0 0 0 0 0 0 0 0 ...
## $ I_RAIN_DRIZZLE : num 0 0 0 0 0 0 0 0 0 0 ...
## $ I_SNOW_ICE : num 0 0 0 0 0 0 0 0 0 0 ...
## $ I_HAIL : num 0 0 0 0 0 0 0 0 0 0 ...
## $ I_THUNDER : num 0 0 0 0 0 0 0 0 0 0 ...
## $ I_TORNADO_FUNNEL: num 0 0 0 0 0 0 0 0 0 0 ...
## $ EA : num 2.1 2.2 2.2 1.9 1.9 2.2 1.9 1.9 1.8 1.6 ...
## $ ES : num 2.9 3.4 3.1 2.6 2.7 3.1 3 2.9 3.1 3.2 ...
## $ RH : num 73.5 66.2 73.3 74.2 70.2 69.3 65.3 68.2 58.4 48.9 ...
## - attr(*, ".internal.selfref")=<externalptr>Plot Maximum and Minimum Temperature Values
Using the first data downloaded for a single station, 955510-99999, plot the temperature for 2010.
library("ggplot2")
library("tidyr")
# Create a dataframe of just the date and temperature values that we want to
# plot
tbar_temps <- tbar[, c("YEARMODA", "TEMP", "MAX", "MIN")]
# Gather the data from wide to long
tbar_temps <-
pivot_longer(tbar_temps, cols = TEMP:MIN, names_to = "Measurement")
ggplot(data = tbar_temps, aes(x = YEARMODA,
y = value,
colour = Measurement)) +
geom_line() +
scale_color_brewer(type = "qual", na.value = "black") +
scale_y_continuous(name = "Temperature") +
scale_x_date(name = "Date") +
ggtitle(label = "Max, min and mean temperatures for Toowoomba, Qld, AU",
subtitle = "Data: U.S. NCEI GSOD") +
theme_classic()
plot of chunk Ex5
Using reformat_GSOD()
You may have already downloaded GSOD data or may just wish to use
your browser to download the files from the server to you local disk and
not use the capabilities of get_GSOD(). In that case the
reformat_GSOD() function is useful.
There are two ways, you can either provide
reformat_GSOD() with a list of specified station files or
you can supply it with a directory containing all of the “STATION.csv”
station files or “YEAR.zip” annual files that you wish to reformat.
Note Any .csv file provided to
reformat_GSOD() will be imported, if it is not a GSOD data
file, this will lead to an error. Make sure the directory and file lists
are clean.
Reformat a List of Local Files
In this example two STATION.csv files are in subdirectories of user’s home directory and are listed for reformatting as a string.
y <- c("~/GSOD/gsod_1960/20049099999.csv",
"~/GSOD/gsod_1961/20049099999.csv")
x <- reformat_GSOD(file_list = y)Reformat all Local Files Found in Directory
In this example all STATION.csv files in the sub-folder GSOD/gsod_1960 will be imported and reformatted.
x <- reformat_GSOD(dsn = "~/GSOD/gsod_1960")Using get_updates()
{GSODR} provides a function, get_updates(), to retrieve
the changelog for the GSOD data and return it in order from newest to
oldest changes to the data set.
Following is an example how to use this function.
{r Ex17, eval=TRUE, message=FALSE}' get_updates()
Using get_inventory()
{GSODR} provides a function, get_inventory() to retrieve
an inventory of the number of weather observations by station-year-month
for the beginning of record through to current.
Following is an example of how to retrieve the inventory and check a station in Toowoomba, Queensland, Australia, which was used in an earlier example.
inventory <- get_inventory()
inventory## *** FEDERAL CLIMATE COMPLEX INTEGRATED SURFACE DATA INVENTORY ***
## This inventory provides the number of weather observations by
## STATION-YEAR-MONTH for beginning of record through October 2024
## Key: <STNID>
## STNID NAME LAT LON ELEV(M)
## <char> <char> <num> <num> <num>
## 1: 008415-99999 <NA> NA NA NA
## 2: 010010-99999 JAN MAYEN(NOR-NAVY) 70.933 -8.667 9
## 3: 010010-99999 JAN MAYEN(NOR-NAVY) 70.933 -8.667 9
## 4: 010010-99999 JAN MAYEN(NOR-NAVY) 70.933 -8.667 9
## 5: 010010-99999 JAN MAYEN(NOR-NAVY) 70.933 -8.667 9
## ---
## 141861: A51256-451 <NA> NA NA NA
## 141862: A51256-451 <NA> NA NA NA
## 141863: A51256-451 <NA> NA NA NA
## 141864: A51256-451 <NA> NA NA NA
## 141865: A51256-451 <NA> NA NA NA
## CTRY STATE BEGIN END COUNTRY_NAME ISO2C
## <char> <char> <int> <int> <char> <char>
## 1: <NA> <NA> NA NA <NA> <NA>
## 2: NO 19310101 20240909 NORWAY NO
## 3: NO 19310101 20240909 NORWAY NO
## 4: NO 19310101 20240909 NORWAY NO
## 5: NO 19310101 20240909 NORWAY NO
## ---
## 141861: <NA> <NA> NA NA <NA> <NA>
## 141862: <NA> <NA> NA NA <NA> <NA>
## 141863: <NA> <NA> NA NA <NA> <NA>
## 141864: <NA> <NA> NA NA <NA> <NA>
## 141865: <NA> <NA> NA NA <NA> <NA>
## ISO3C YEAR JAN FEB MAR APR MAY JUN JUL
## <char> <int> <int> <int> <int> <int> <int> <int> <int>
## 1: <NA> 2020 0 0 14 0 0 0 0
## 2: NOR 2020 736 695 744 717 744 718 743
## 3: NOR 2021 686 562 729 710 733 654 726
## 4: NOR 2022 549 513 292 98 0 0 137
## 5: NOR 2023 738 657 715 713 735 666 735
## ---
## 141861: <NA> 2020 2165 1455 2144 2125 2199 2123 2112
## 141862: <NA> 2021 2085 1992 2217 1975 2146 2092 2227
## 141863: <NA> 2022 2203 1937 2204 2144 2218 2119 2224
## 141864: <NA> 2023 2006 1988 2172 1993 2063 2088 2189
## 141865: <NA> 2024 2223 1956 2215 2152 2221 2004 2210
## AUG SEP OCT NOV DEC
## <int> <int> <int> <int> <int>
## 1: 0 0 0 0 0
## 2: 742 718 694 708 740
## 3: 717 712 737 714 630
## 4: 0 292 709 708 724
## 5: 726 693 729 698 741
## ---
## 141861: 2192 2083 2079 2074 2187
## 141862: 2170 2080 2163 2120 2168
## 141863: 2209 2137 1743 2126 2201
## 141864: 2182 2147 2199 2120 2197
## 141865: 2124 1703 0 0 0## *** FEDERAL CLIMATE COMPLEX INTEGRATED SURFACE DATA INVENTORY ***
## This inventory provides the number of weather observations by
## STATION-YEAR-MONTH for beginning of record through October 2024
## Key: <STNID>
## STNID NAME LAT LON ELEV(M) CTRY
## <char> <char> <num> <num> <num> <char>
## 1: 955510-99999 TOOWOOMBA AIRPORT -27.55 151.917 642 AS
## 2: 955510-99999 TOOWOOMBA AIRPORT -27.55 151.917 642 AS
## 3: 955510-99999 TOOWOOMBA AIRPORT -27.55 151.917 642 AS
## 4: 955510-99999 TOOWOOMBA AIRPORT -27.55 151.917 642 AS
## 5: 955510-99999 TOOWOOMBA AIRPORT -27.55 151.917 642 AS
## STATE BEGIN END COUNTRY_NAME ISO2C ISO3C YEAR
## <char> <int> <int> <char> <char> <char> <int>
## 1: 19980301 20240909 AUSTRALIA AU AUS 2020
## 2: 19980301 20240909 AUSTRALIA AU AUS 2021
## 3: 19980301 20240909 AUSTRALIA AU AUS 2022
## 4: 19980301 20240909 AUSTRALIA AU AUS 2023
## 5: 19980301 20240909 AUSTRALIA AU AUS 2024
## JAN FEB MAR APR MAY JUN JUL AUG SEP OCT
## <int> <int> <int> <int> <int> <int> <int> <int> <int> <int>
## 1: 246 232 248 238 248 348 493 492 480 496
## 2: 485 483 742 720 743 716 744 737 719 744
## 3: 743 672 739 716 739 716 728 742 716 726
## 4: 738 663 730 715 737 701 733 729 700 730
## 5: 741 691 626 662 714 703 719 707 708 310
## NOV DEC
## <int> <int>
## 1: 475 496
## 2: 720 726
## 3: 713 726
## 4: 710 744
## 5: 0 0Using update_internal_isd_history()
{GSODR} uses internal databases of station data from the NCEI to provide location and other metadata, e.g. elevation, station names, WMO codes, etc. to make the process of querying for weather data faster. This database is created and packaged with {GSODR} for distribution and is updated with new releases. Users have the option of updating these databases after installing GSODR. While this option gives the users the ability to keep the database up-to-date and gives GSODR’s authors flexibility in maintaining it, this also means that reproducibility may be affected since the same version of {GSODR} may have different databases on different machines. If reproducibility is necessary, care should be taken to ensure that the version of the databases is the same across different machines.
The database file isd_history.rda can be located on your
local system by using the following command,
paste0(.libPaths(), "/GSODR/extdata")[1], unless you have
specified another location for library installations and installed
{GSODR} there, in which case it would still be in
GSODR/extdata.
To update GSODR’s internal database of station locations
simply use update_station_list(), which will update the
internal station database according to the latest data available from
the NCEI.
update_internal_isd_history()Notes
WMO Resolution 40. NOAA Policy
The data summaries provided here are based on data exchanged under the World Meteorological Organization (WMO) World Weather Watch Program according to WMO Resolution 40 (Cg-XII). This allows WMO member countries to place restrictions on the use or re-export of their data for commercial purposes outside of the receiving country. Data for selected countries may, at times, not be available through this system. Those countries’ data summaries and products which are available here are intended for free and unrestricted use in research, education, and other non-commercial activities. However, for non-U.S. locations’ data, the data or any derived product shall not be provided to other users or be used for the re-export of commercial services.
Appendices
Appendix 1: GSODR Final Data Format, Contents and Units
{GSODR} formatted data include the following fields and units:
STNID - Station number (WMO/DATSAV3 number) for the location;
NAME - Unique text identifier;
CTRY - Country in which the station is located. This field is the original FIPS code that NCEI provides;
COUNTRY_NAME - Country in which the station is located. This field is the country name in English language;
ISO2C - Country in which the station is located. This field is the two letter ISO country code;
ISO3C - Country in which the station is located. This field is the three letter ISO country code;
LAT - Latitude. Station dropped in cases where values are < -90 or > 90 degrees or Lat = 0 and Lon = 0;
LON - Longitude. Station dropped in cases where values are < -180 or > 180 degrees or Lat = 0 and Lon = 0;
ELEVATION - Elevation in metres;
YEARMODA - Date in YYYYMMDD format;
YEAR - The year (YYYY);
MONTH - The month (mm);
DAY - The day (dd);
YDAY - Sequential day of year (not in original GSOD);
TEMP - Mean daily temperature converted to degrees C to tenths. Missing =
NA;TEMP_ATTRIBUTES - Number of observations used in calculating mean daily temperature;
DEWP - Mean daily dew point converted to degrees C to tenths. Missing =
NA;DEWP_ATTRIBUTES - Number of observations used in calculating mean daily dew point;
SLP - Mean sea level pressure in millibars to tenths. Missing =
NA;SLP_ATTRIBUTES - Number of observations used in calculating mean sea level pressure;
STP - Mean station pressure for the day in millibars to tenths. Missing =
NA;STP_ATTRIBUTES - Number of observations used in calculating mean station pressure;
VISIB - Mean visibility for the day converted to kilometres to tenths. Missing =
NA;VISIB_ATTRIBUTES - Number of observations used in calculating mean daily visibility;
WDSP - Mean daily wind speed value converted to metres/second to tenths. Missing =
NA;WDSP_ATTRIBUTES - Number of observations used in calculating mean daily wind speed;
MXSPD - Maximum sustained wind speed reported for the day converted to metres/second to tenths. Missing =
NA;GUST - Maximum wind gust reported for the day converted to metres/second to tenths. Missing =
NA;MAX - Maximum temperature reported during the day converted to Celsius to tenths–time of max temp report varies by country and region, so this will sometimes not be the max for the calendar day. Missing =
NA;MAX_ATTRIBUTES - Blank indicates max temp was taken from the explicit max temp report and not from the ‘hourly’ data. An “*” indicates max temp was derived from the hourly data (i.e., highest hourly or synoptic-reported temperature);
MIN - Minimum temperature reported during the day converted to Celsius to tenths–time of min temp report varies by country and region, so this will sometimes not be the max for the calendar day. Missing =
NA;MIN_ATTRIBUTES - Blank indicates max temp was taken from the explicit min temp report and not from the ‘hourly’ data. An “*” indicates min temp was derived from the hourly data (i.e., highest hourly or synoptic-reported temperature);
PRCP - Total precipitation (rain and/or melted snow) reported during the day converted to millimetres to hundredths; will usually not end with the midnight observation, i.e., may include latter part of previous day. A value of “.00” indicates no measurable precipitation (includes a trace). Missing = NA; Note: Many stations do not report ‘0’ on days with no precipitation– therefore,
NAwill often appear on these days. For example, a station may only report a 6-hour amount for the period during which rain fell. SeeFLAGS_PRCPcolumn for source of data;-
PRCP_ATTRIBUTES -
A = 1 report of 6-hour precipitation amount;
B = Summation of 2 reports of 6-hour precipitation amount;
C = Summation of 3 reports of 6-hour precipitation amount;
D = Summation of 4 reports of 6-hour precipitation amount;
E = 1 report of 12-hour precipitation amount;
F = Summation of 2 reports of 12-hour precipitation amount;
G = 1 report of 24-hour precipitation amount;
H = Station reported ‘0’ as the amount for the day (e.g. from 6-hour reports), but also reported at least one occurrence of precipitation in hourly observations–this could indicate a trace occurred, but should be considered as incomplete data for the day;
I = Station did not report any precipitation data for the day and did not report any occurrences of precipitation in its hourly observations–it’s still possible that precipitation occurred but was not reported;
SNDP - Snow depth in millimetres to tenths. Missing =
NA;I_FOG - Indicator for fog, (1 = yes, 0 = no/not reported) for the occurrence during the day;
I_RAIN_DRIZZLE - Indicator for rain or drizzle, (1 = yes, 0 = no/not reported) for the occurrence during the day;
I_SNOW_ICE - Indicator for snow or ice pellets, (1 = yes, 0 = no/not reported) for the occurrence during the day;
I_HAIL - Indicator for hail, (1 = yes, 0 = no/not reported) for the occurrence during the day;
I_THUNDER - Indicator for thunder, (1 = yes, 0 = no/not reported) for the occurrence during the day;
I_TORNADO_FUNNEL - Indicator for tornado or funnel cloud, (1 = yes, 0 = no/not reported) for the occurrence during the day;
EA - Mean daily actual vapour pressure as calculated using improved August-Roche-Magnus approximation (Alduchov and Eskridge 1996). Missing =
NA;ES - Mean daily saturation vapour pressure as calculated using improved August-Roche-Magnus approximation (Alduchov and Eskridge 1996). Missing =
NA;RH - Mean daily relative humidity as calculated using improved August-Roche-Magnus approximation (Alduchov and Eskridge 1996). Missing =
NA.
