Daily data from various sources (aerological soundings for three geopotential heights, reanalysis, weather station, FarmImpact measurements) were analyzed for the 2010–2022 period by k-means cluster analysis. The basic pattern of the classification of 5 weather types derived from cluster analysis is the seasonal change of near-ground circulation depending on the strength and position of the controlling pressure centers (South Atlantic Anticyclone and either dynamic mid-latitude or thermal inland lows). In winter, the active pressure centers are either mid-latitude cyclones with frontal passage and cold air influx, strong wind and high rainfall (Type 2 with overall minor frequencies) or cyclones further south in the mid-latitude west wind drift with frontal systems typically not reaching the Southwestern Cape (Type 4 as the more frequent type). In summer, Type 3 represents the typical synoptic pattern of strong inland thermal Lows, a seasonally strong South Atlantic Anticyclone and following high wind speeds and temperatures in the southern Western Cape. Microclimatic processes like rainfall and evapotranspiration and the resulting water balance on farmlands of the southern Western Cape are largely driven by the mesoscale atmospheric dynamics as could be shown for the Rust en Vrede Farm site. Irrigation water consumption or mechanical fruit damage caused by high wind speeds is defined by frequencies of dry and windy weather types in the growing season (Types 3 and 1) as well as of rain-bearing types (Types 2, 4 and 5) over the winter half year, determining soil, groundwater and reservoir water storage.