Homogenization and interpolation of relative humidity hourly values with MASH and MISH software

To understand and study the climate, there is a need to create high-quality climatological databases. At the Climate Department of the OMSZ (Hungarian Meteorological Service), we use MASH (Multiple Analysis of Series of Homogenization) and MISH (Meteorological Interpolation based on Surface Homogenized Data Basis) software to produce a spatially and temporally representative database. However, these systems were developed for daily and monthly data series, so some improvements were required when applying them to hourly relative humidity data. The problem relates to the issue of the daily cycle. The aim of this article is to show how the data set of hourly values of the relative humidity measurements was prepared. To construct the grid point database, a homogenized data set of 41 stations for the period 1961-2020 was used; this was then interpolated into to a regular grid with a resolution of 0.1 degrees. At the end of the study, the hourly and daily data gridded series are compared.