Hourly gridded air temperatures of South Africa derived from MSG SEVIRI

Monitoring of climate variables such as air temperature is gaining increasing importance under climate change. This study aimed at developing an hourly gridded 3.5 x 3.5 km air temperature (T-air) data set for entire South Africa. In a Random Forest approach, MSG SEVIRI data from 2010 to 2014 were used and related to T-air measured by 78 weather stations. An external validation on new climate stations and years that were not used for model training indicated the ability of the model to predict T-air with a RMSE of 2.61 degrees C and a R-2 of 0.89. The resulting model can be applied to the entire MSG SEVIRI time series since 2004. It hence allows for spatiotemporal pattern analysis as well as for the detection of trends which is relevant in the context of climate change.