NASA POWER

NASA POWER (Prediction of Worldwide Energy Resources) provides global gridded meteorological data at 0.5° resolution from 1981 to near-real-time (2-3 day delay). Parameters include temperature, precipitation, relative humidity, solar radiation (GHI, DNI, DIF), and wind speed — the exact variables needed for solar panel sizing, crop modelling, and water balance calculations. It has a straightforward REST API, an interactive Data Access Viewer, and is widely used in regions without dense ground instrumentation.