Among the most useful databases containing reanalyzed historical climate data are the ERA5 hourly data on single levels, and the GPCC¹ Full Data Monthly Precipitation Product Version 2022 .

ERA5 is the fifth generation ECMWF² reanalysis for the global climate and weather for the past eight decades. ERA5 provides hourly estimates for a large number of atmospheric, ocean-wave and land-surface quantities from 1940 onwards in the form of a global grid with 0.25 degree spatial resolution. Monthly summaries are available, which makes the dataset interesting for analyzing climatic variability and change through commonly used meteorological variables, such as precipitation, temperature, radiation, evaporation, wind, etc.

The GPCC Full Data Reanalysis dataset³, currently in version 2022, contains monthly global land-surface precipitation data from 75,000 precipitation stations world-wide with record durations of 10 years or longer. This product contains the monthly totals on a regular grid with a maximum spatial resolution of 0.25° x 0.25° and a temporal coverage from January 1891 to December 2020.

NOTE: The GPCC datasets have been used in some of our studies – notably Pub.77 (Near East), Pub.94 (Central Asia and NW China), Pub.100 (Africa) and Pub.109 (Iraq and Jordan) for mapping annual precipitation probabilities and trends, changes in precipitation variability, and drought and wetness periods.

Acronyms and sources:
• (1) GPCC: Global Precipitation Climatology Center
• (2) ECMWF: European Center for Medium-Term Weather Forecasts
• (3) Source: Schneider, Udo; Hänsel, Stephanie; Finger, Peter; Rustemeier, Elke; Ziese, Markus (2022): GPCC Full Data Monthly Product Version 2022 at 0.25°: Monthly Land-Surface Precipitation from Rain-Gauges built on GTS-based and Historical Data.