How the calendar is created
Why flowering times vary
No flower follows the calendar exactly. Temperature, weather and location all affect when the first blossoms open. That is why we show not only a single date, but also the period in which flowering has usually been observed.
Observations from the German Weather Service
The flowering times are based on quality-checked plant observations from the German Weather Service’s current annual data.
A reliable midpoint
The displayed midpoint is the median of the observations. This makes it less sensitive to individual years with particularly early or late flowering.
A guide, not a forecast
The calendar shows typical flowering times across Germany, not a live forecast. Local flowering may start earlier or later depending on elevation, region and weather.
Source: Deutscher Wetterdienst, Climate Data Center (CDC) ↗,
CC BY 4.0; own evaluation. Dataset generated on September 13, 2026