Summer day
Temperature & humidity
In German weather statistics, a summer day has a maximum air temperature of at least 25 °C. The calendar month does not determine the classification.
The calendar does not decide
A day counts as a summer day if its measured maximum reaches 25.0 °C or more. A warm April day can qualify, while a rainy July day reaching only 19 °C does not. The calendar is welcome to disagree.
What the definition does not require
- Temperature need not stay above 25 °C all day.
- The weather need not be sunny or dry.
- A maximum of at least 30 °C also makes it a hot day.
Summer days in climate records
The record counts all days when the maximum temperature reaches the threshold. Hot days are already included and must not be added again. Long-term averages may have decimal places; an individual day counts as a whole day.