Rank 63 of 80
10.8 hot days a year, average 2016–2025. In 1951–1960 it was 3.3.
Bielefeld has no historical counterpart: no major German city was as hot in 1951–1960 as Bielefeld is today.
| Period | Hot days | Rank | |
|---|---|---|---|
| 1951–1960 | 3.3 | 62 | |
| 1961–1970 | 3.2 | 66 | |
| 1971–1980 | 4.5 | 61 | |
| 1981–1990 | 4.8 | 59 | |
| 1991–2000 | 7.2 | 63 | |
| 2001–2010 | 8.0 | 65 | |
| 2006–2015 | 6.9 | 69 | |
| 2016–2025 | 10.8 | 63 |
This figure describes the location of Bielefeld. No city administration decides on location. On shade over streets, schoolyards and playgrounds, it does.
What can be changed
This measures the share of residential surroundings covered by trees – from the satellite, weighted by the population of the same 100 m cells as the heat figure above. Both figures therefore apply to the same places and can stand side by side. Parks, cemeteries and gardens count. The city’s stock of street trees requires the tree register.
Cities with a similar number of hot days and a similar size to Bielefeld that have clearly more green where people live:
Bielefeld has a published heat action plan: „Hitzeaktionsplanung Stadt Bielefeld“ (2024).
Research as of 24 October 2026. Corrections and tips to kontakt@julianzuber.de.
For Bielefeld this has been analysed across the city area: trees, land, heat stress. deutschland-hitzesicher.de/bielefeld-hitzesicher (in German)
Each city has its own access to its map. Enquiries to kontakt@julianzuber.de.