← All major cities

Rank 68 of 80

Ulm

10.1 hot days a year, average 2016–2025. In 1951–1960 it was 4.2.

Grid and weather station typically differ by about 0.9 days. If the value is shifted by that much, the city lies on one of the places 60 to 74. How it was checked.

Ulm has no historical counterpart: no major German city was as hot in 1951–1960 as Ulm is today.

10.1Hot days today
4.2Hot days 1951–1960
23.5hottest year: 2003
41 → 68Rank then and now
37.12026, provisional

2026: 37.1 hot days up to the cut-off date – 3.7 times the decade average. This puts Ulm above its previous record year 2003 (23.5 days). The count covers the first 292 days of the year, up to 19 October. The year is therefore not yet complete, and the figure comes from the daily grid rather than the annual grid, which the DWD only publishes after the end of the year. Over the three most recent years available in both, the two agree on average (+0.18 days); for a single city they typically differ by 1.5 days, in individual cases by up to 6.8. This figure is not included in any decade average or any rank on this page.

010203040195119882025
010203040195119882025
1951–2025, axis 0 to 46 days. Grey: the national median. The same axis as on every other city page – the lines can be compared with one another.

Decade by decade

PeriodHot daysRank
1951–19604.241
1961–19704.544
1971–19802.775
1981–19904.267
1991–20004.877
2001–20107.371
2006–20158.744
2016–202510.168

Context

This figure describes the location of Ulm. No city administration decides on location. On shade over streets, schoolyards and playgrounds, it does.

What can be changed

Location is fixed, the residential surroundings are not

30.2 %of the residential surroundings is tree cover
Rank 58of 80 for green where people live

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.

Examples in the same location

Cities with a similar number of hot days and a similar size to Ulm that have clearly more green where people live:

  1. Ulm10.1 days30.2 %
  2. Siegen9.7 days50.2 %
  3. Mülheim an der Ruhr10.9 days49.1 %
  4. Chemnitz10.7 days45.8 %

Hot days per year, average 2016–2025, and green where people live. Compared are cities no more than 1.5 hot days apart, at most three times as large or as small, with at least 5.0 percentage points more green. Green also depends on urban form and topography; the comparison shows what occurs in the same location and is not a grade for any administration.

Heat action plan

We did not find a published heat action plan for Ulm. That does not mean there is none: plans may exist internally or be called something else.

Research as of 24 October 2026. Corrections and tips to kontakt@julianzuber.de.

The map for this city

For Ulm this has been analysed across the city area: trees, land, planting search areas. deutschland-hitzesicher.de/ulm-hitzesicher (in German)

Each city has its own access to its map. Enquiries to kontakt@julianzuber.de.

Neighbours in the ranking

  1. 66Wuppertal10.6
  2. 67Hagen10.1
  3. 68Ulm10.1
  4. 69Kassel10.0
  5. 70Remscheid9.9

Hot days per year, average 2016–2025. All 80 at a glance