Altdorf climate — normals and trends
Altdorf (Switzerland) has a warm-summer humid continental climate (Dfb) under the Köppen-Geiger classification. Its mean annual temperature is 4.6 °C and it receives 1,931 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is July (13.7 °C on average) and the coldest is January (-4.5 °C). Rainfall peaks in August.
Altdorf averages 163 frost days, 0 hot days (≥ 30 °C) and 197 rainy days per year.
Altdorf has warmed by +2.6 °C between 1940 and 2025, or +0.31 °C per decade. This trend is statistically significant.
The number of frost days there went from about 191 to 135 per year over the period.
The hottest day of the period reached 29.5 °C (on 18 June 2013) and the coldest -26.2 °C (on 14 February 1940).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
AltdorfCanton of Uri
- coords
- 46.88°, 8.64°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
4.6°C
Average daily high
8.5°C
Average daily low
0.8°C
Annual rainfall
1,931mm
Sunshine / day
8.7h
Mean relative humidity
80%
Average peak wind
7.5km/h
Seasonal range
18.2°C
Frost days (< 0 °C)
163 d/yr
Hot days (≥ 30 °C)
0 d/yr
Rainy days (≥ 1 mm)
197 d/yr
Annual snowfall
464.0 cm
Average feels-like high
6.7 °C
Average feels-like low
-1.9 °C
Average peak gust
34.6 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
13.0 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.6 °C
since 1940
+0.3 °C per decade · r² = 0.62 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
29.5 °C
18 June 2013
Coldest day
-26.2 °C
14 February 1940
Wettest day
84 mm
6 August 1985
Windiest day
20.9 km/h
21 October 2014
Strongest gust
142.6 km/h
27 February 1990
Hottest feels-like
32.1 °C
5 July 2015
Coldest feels-like
-30.6 °C
14 February 1940
Snowiest day
37.2 cm
14 January 2021
Sunniest day
15.0 h
5 June 1940
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 1.0 °C | +2.6 °C | 115 mm | -14 mm |
| Feb | 3.0 °C | +2.8 °C | 38 mm | -83 mm |
| Mar | 7.1 °C | +3.3 °C | 107 mm | -27 mm |
| Apr | 11.6 °C | +4.3 °C | 123 mm | -25 mm |
| May | 13.1 °C | +1.0 °C | 232 mm | +48 mm |
| Jun | 21.3 °C | +5.3 °C | 130 mm | -86 mm |
| Jul | 17.6 °C | -0.7 °C | 333 mm | +115 mm |
| Aug | 20.0 °C | +2.0 °C | 255 mm | +36 mm |
| Sep | 15.1 °C | +0.2 °C | 227 mm | +67 mm |
| Oct | 9.8 °C | -0.4 °C | 127 mm | -0 mm |
| Nov | 4.8 °C | +1.4 °C | 133 mm | -9 mm |
| Dec | 3.0 °C | +3.8 °C | 37 mm | -98 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Altdorf?
Altdorf has a warm-summer humid continental climate (Köppen Dfb). Over 1940-2025, the average annual temperature is 4.6 °C and it receives 1,931 mm of precipitation per year.
What is the hottest day ever recorded in Altdorf?
The hottest day measured in Altdorf between 1940 and 2025 was 18 June 2013, reaching 29.5 °C.
What is the coldest day in Altdorf?
The coldest day measured in Altdorf between 1940 and 2025 was 14 February 1940, at -26.2 °C.
Does it snow in Altdorf?
Yes. Altdorf gets on average 464.0 cm of snow per year and has around 163 frost days.
Has the climate of Altdorf warmed?
Yes: Altdorf warmed by +2.6 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Altdorf?
The wettest day measured in Altdorf between 1940 and 2025 was 6 August 1985, with 84 mm of rain in 24 hours.
What was the windiest day in Altdorf?
The windiest day measured in Altdorf between 1940 and 2025 was 21 October 2014, with winds reaching 20.9 km/h.
What is the warmest month in Altdorf?
The warmest month in Altdorf is July (13.7 °C on average); the coldest is January (-4.5 °C).
How much does it rain in Altdorf?
Altdorf receives on average 1,931 mm of precipitation per year, spread over about 197 rainy days.
Is it sunny in Altdorf?
Altdorf gets on average 8.7 hours of sunshine per day, roughly 3,175 hours per year over 1940-2025.
What is the biggest single-day snowfall in Altdorf?
The heaviest 24-hour snowfall measured in Altdorf between 1940 and 2025 was 14 January 2021, with 37.2 cm.
Are there tropical nights in Altdorf?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Altdorf.
What was the most extreme apparent temperature in Altdorf?
In Altdorf, between 1940 and 2025, the highest apparent temperature reached 32.1 °C on 5 July 2015, and the lowest was -30.6 °C on 14 February 1940.
Compare Altdorf with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Altdorf