Solar & UV Data Center
Sunshine and UV for any spot on the map. NASA POWER gives satellite-based hourly radiation and UV back to 2001; Open-Meteo adds reanalysis radiation and a UV forecast. Upload your weather station's solar readings to see whether its sensor reads high or low, and by how much.
1 · Place and dates
NASA POWER daily totals lag about 5 days behind today; its hourly values lag about two months, so for recent weeks the hourly chart uses Open-Meteo. Times are shown in the local time of the point.
Tap the map to move the point.
Summary
Hourly solar radiation (W/m²)
All-sky = what actually reached the ground. Clear-sky = what would have reached it with no clouds; the gap between them is cloud cover.
Daily solar energy (kWh/m²)
UV index
UV 3–5 moderate, 6–7 high, 8–10 very high, 11+ extreme.
2 · Check your station's solar sensor (optional)
Upload a CSV from your station that has a time column and a solar radiation column in W/m² (Ecowitt, Weather Underground, WeeWX and Davis exports all work). The dates above are set from your file automatically. Only hours when the reference shows good sunshine (over 200 W/m²) are used, so night and deep-shade hours don't skew the result.
NREL NSRDB (research-grade, needs your own free key)
The National Solar Radiation Database has 30-minute to hourly GHI/DNI/DHI back to 1998. It requires a free API key and an email address from developer.nrel.gov/signup. This builds the download link for the point above; open it and the CSV downloads straight from NREL. Nothing is stored here.
Sources: NASA Langley POWER project (CERES/MERRA-2), Open-Meteo (ERA5 reanalysis and forecast models), NREL NSRDB, OpenStreetMap / Nominatim for search. Ported and combined from the CPA Weather Lab UV & Solar downloader and solar calibration console.