Rank 12 of 80
21.1 hot days a year, average 2016–2025. In 1951–1960 it was 6.9.
Jena has no historical counterpart: no major German city was as hot in 1951–1960 as Jena is today.
| Period | Hot days | Rank | |
|---|---|---|---|
| 1951–1960 | 6.9 | 15 | |
| 1961–1970 | 7.4 | 16 | |
| 1971–1980 | 7.7 | 20 | |
| 1981–1990 | 6.2 | 41 | |
| 1991–2000 | 10.0 | 24 | |
| 2001–2010 | 15.1 | 13 | |
| 2006–2015 | 15.6 | 6 | |
| 2016–2025 | 21.1 | 12 |
This figure describes the location of Jena. 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.
Among the cities with a similar number of hot days and a similar size, Jena has the most green where people live.
Jena has a published heat action plan: „Hitzeaktionsplan der Stadt Jena“ (2025).
Research as of 24 October 2026. Corrections and tips to kontakt@julianzuber.de.
For Jena this has been analysed across the city area: trees, land, planting search areas. deutschland-hitzesicher.de/jena-hitzesicher (in German)
Each city has its own access to its map. Enquiries to kontakt@julianzuber.de.