Input data set: ERA5

ERA5 global meteorological forcing data processed for ISIMIP2a. Original ERA5 data were aggregated in space and time to 0.5° and temporal resolution, respectively. Prior to that aggregation, near-surface wind speed, relative and specific humidity were derived from available ERA5 variables: Near-surface wind speed was computed from near-surface easterly and northerly wind components. Near-surface relative and specific humidity were computed from surface air pressure, near-surface air temperature and near-surface dew point using the equations of Buck (1981, doi:10.1175/1520-0450(1981)020<1527:NEFCVP>2.0.CO;2) as described in Buck Research CR-1A User's Manual, Appendix 1 (

Data Type: Observed atmospheric climate
Simulation rounds: ISIMIP2a
Scenarios: hist-obs
Variables: tasmax, tas, tasmin, rlds, hurs, huss, wind, rsds, prsn, ps, pr
Data source

ERA5 reanalysis data at 0.25° spatial and hourly temporal resolution (

Download Instructions

For ISIMIP participants, these files are available for download on the DKRZ server using the path /ISIMIP/ISIMIP2a/InputData/climate_co2/climate/HistObs/ERA5/.

For external users, these data will soon be made available on the ISIMIP ESGF server ( Currently they are available via an rsync facility (described here:, for which the password will be provided upon request (