Hot day
Temperature & humidity Day with at least 30 °C
In German weather statistics, a hot day reaches at least 30 °C air temperature. The threshold applies to a shielded measurement, not a thermometer in direct sunshine.
Counting starts at thirty
The meteorological threshold is a daily maximum of at least 30.0 °C. A brief exceedance is enough. A thermometer on a sunny wall is not directly suitable: sunshine and the wall heat the instrument as well as the air.
A hot day is also a summer day
Summer days begin at 25 °C, so every hot day is already included in the summer-day count. Adding the two figures would count the hottest days twice.
Comparing annual counts
The number of hot days varies from year to year. A climate average combines many years and always belongs to a location and reference period. The frequency alone also does not tell you how well a home cools down at night.
A statistical threshold, not a personal limit
Humid conditions at 29 °C may feel more demanding than 30 °C in other circumstances. Hot nights, activity and lack of shade matter too. “Not yet a hot day” is a statistical statement, not an all-clear for heat exposure.