CWOP Solar Radiation Data

About one fifth of active CWOP members send solar radiation data along with other weather data and most use this Solar Radiation Sensor. Each of these Davis sensors has been "calibrated against a secondary standard which is calibrated periodically against an Eppley Precision Spectral Pyranometer in natural daylight". Click here for information on solar radiation measurements. The CWOP solar radiation data are acquired by findu.com and available for viewing here, where call is station ID in findU, xsize and ysize determine size of the graph, and last is the number of previous hours covered on the x axis.

NOAA operates the SurfRad Network with these Eppley Precision Spectral Pyranometers to monitor solar radiation at seven sites around the US 48-state area. The downwelling solar radiation data from these sites are available to compare with CWOP solar radiation data. The NOAA SurfRad data have IDs that start with the letters of "Surf Rad Calibration (SRC...) and are: SRCBON Bondville, IL; SRCTBL Boulder, CO; SRCDRA Desert Rock, NV; SRCFPK Fort Peck, MT; SRCGWN Goodwin Creek, MS; SRCPSU Penn State, PA; and SRCSXF Sioux Falls, SD.

This tool will accept a CWOP ID (or SRC ID) and date in the boxes below, and then return one of three data sets. The first, a listing of the received raw packets from that station for the specified date and a listing of the selected number of nearby solar stations. The second, a CSV listing of the time, solar radiation, wind, temperature values for a single station. The third, a CSV listing of time and solar radiation for between one and twenty (closest first) stations.

The units for time are decimal UTC hours; for solar radiation, Watts per square meter; for wind, miles per hour; and for temperature, degrees F. Note that only packets with non-zero values of solar radiation are listed. Entering ? for Call Sign and a recent date below will return a list of stations sending solar radiation data on that day.


Call Sign [CW/DW/EW/FW.... or Ham Call or SRC...]
Date Desired [Feb 09, 2017 is 20170209]
Compare with only NOAA SurfRad stations
Number of nearby solar radiation stations
Output Display Format Single Station raw packets with non-zero Solar Radiation
Single Station of Time, Solar Radiation, Wind, Temperature (CSV)
Multi-Station Comparison of Time, Solar Radiation (CSV)

Solar Radiation Raw Data Archive

All of the solar radiation data received by CWOP since 2009 have been archived. This collection is described in Six Years of the Solar Radiation Data Archive: Citizen Weather Observer Program which summarizes the holdings, now comprising more than a quarter billion reports. Those reports have been collected into an Amazon Web Services database as described by Paper 12.1 in the Innovative Measurements Session at the 2016 AMS Annual Meeting.

The raw data packets used to get the solar radiation data in the archive are available for download as daily text files compressed by gzip. After download, they have to be ungzipped to be viewed. The report linked above has a script for downloading the files. The NOAA SurfRad data discussed above are also included in these files.


The units are: time, decimal UTC hours; solar radiation, Watts per square meter; wind, miles per hour and degrees from true north; and temperature, degrees F. Note that only raw packets with non-zero values of solar radiation are listed. The SurfRad data files start and end at 0000z. All other data files start and end one hour earlier.