Altamont climate — normals and trends
Altamont (United States) has a warm-summer mediterranean continental climate (Dsb) under the Köppen-Geiger classification. Its mean annual temperature is 8.3 °C and it receives 599 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 (20.1 °C on average) and the coldest is January (-1.5 °C). Rainfall peaks in December.
Altamont averages 133 frost days, 28 hot days (≥ 30 °C) and 96 rainy days per year.
Altamont has warmed by +3.1 °C between 1940 and 2025, or +0.36 °C per decade. This trend is statistically significant.
The number of frost days there went from about 155 to 111 per year over the period.
The hottest day of the period reached 39.1 °C (on 28 June 2021) and the coldest -26.7 °C (on 21 December 1990).
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
AltamontOregon
- coords
- 42.21°, -121.74°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
8.3°C
Average daily high
14.4°C
Average daily low
2.9°C
Annual rainfall
599mm
Sunshine / day
10.2h
Mean relative humidity
66%
Average peak wind
12.7km/h
Seasonal range
21.6°C
Frost days (< 0 °C)
133 d/yr
Hot days (≥ 30 °C)
28 d/yr
Rainy days (≥ 1 mm)
96 d/yr
Annual snowfall
192.0 cm
Average feels-like high
11.8 °C
Average feels-like low
0.1 °C
Average peak gust
33.3 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
17.5 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+3.1 °C
since 1940
+0.4 °C per decade · r² = 0.71 · 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
39.1 °C
28 June 2021
Coldest day
-26.7 °C
21 December 1990
Wettest day
67 mm
22 December 1964
Windiest day
43.0 km/h
12 October 1962
Strongest gust
108.4 km/h
6 December 1952
Hottest feels-like
38.3 °C
30 July 2003
Coldest feels-like
-31.9 °C
21 December 1990
Snowiest day
32.6 cm
17 January 1951
Sunniest day
14.8 h
15 June 1945
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 | 6.1 °C | +3.5 °C | 56 mm | -33 mm |
| Feb | 3.2 °C | -1.7 °C | 164 mm | +95 mm |
| Mar | 9.0 °C | +1.3 °C | 107 mm | +37 mm |
| Apr | 15.5 °C | +3.6 °C | 31 mm | -15 mm |
| May | 20.0 °C | +2.6 °C | 16 mm | -26 mm |
| Jun | 25.7 °C | +3.1 °C | 7 mm | -17 mm |
| Jul | 29.3 °C | +0.9 °C | 12 mm | +4 mm |
| Aug | 28.3 °C | +0.7 °C | 18 mm | +6 mm |
| Sep | 24.4 °C | +0.9 °C | 25 mm | +7 mm |
| Oct | 14.7 °C | -1.5 °C | 48 mm | +4 mm |
| Nov | 10.6 °C | +3.3 °C | 43 mm | -36 mm |
| Dec | 6.7 °C | +3.9 °C | 139 mm | +41 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 Altamont?
Altamont has a warm-summer mediterranean continental climate (Köppen Dsb). Over 1940-2025, the average annual temperature is 8.3 °C and it receives 599 mm of precipitation per year.
What is the hottest day ever recorded in Altamont?
The hottest day measured in Altamont between 1940 and 2025 was 28 June 2021, reaching 39.1 °C.
What is the coldest day in Altamont?
The coldest day measured in Altamont between 1940 and 2025 was 21 December 1990, at -26.7 °C.
Does it snow in Altamont?
Yes. Altamont gets on average 192.0 cm of snow per year and has around 133 frost days.
Has the climate of Altamont warmed?
Yes: Altamont warmed by +3.1 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Altamont?
The wettest day measured in Altamont between 1940 and 2025 was 22 December 1964, with 67 mm of rain in 24 hours.
What was the windiest day in Altamont?
The windiest day measured in Altamont between 1940 and 2025 was 12 October 1962, with winds reaching 43.0 km/h.
What is the warmest month in Altamont?
The warmest month in Altamont is July (20.1 °C on average); the coldest is January (-1.5 °C).
How much does it rain in Altamont?
Altamont receives on average 599 mm of precipitation per year, spread over about 96 rainy days.
Is it sunny in Altamont?
Altamont gets on average 10.2 hours of sunshine per day, roughly 3,723 hours per year over 1940-2025.
What is the biggest single-day snowfall in Altamont?
The heaviest 24-hour snowfall measured in Altamont between 1940 and 2025 was 17 January 1951, with 32.6 cm.
Are there tropical nights in Altamont?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Altamont.
What was the most extreme apparent temperature in Altamont?
In Altamont, between 1940 and 2025, the highest apparent temperature reached 38.3 °C on 30 July 2003, and the lowest was -31.9 °C on 21 December 1990.
Compare Altamont with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Altamont