Portland climate — normals and trends
Portland (United States) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 21.9 °C and it receives 732 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 August (28.4 °C on average) and the coldest is January (13.6 °C). Rainfall peaks in September.
Portland averages 2 frost days, 101 hot days (≥ 30 °C) and 103 rainy days per year.
Portland has warmed by +1.3 °C between 1940 and 2025, or +0.15 °C per decade. This trend is statistically significant.
The hottest day of the period reached 40.1 °C (on 24 September 2005) and the coldest -9.7 °C (on 23 December 1989).
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
PortlandTexas
- coords
- 27.88°, -97.32°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
21.9°C
Average daily high
25.4°C
Average daily low
18.7°C
Annual rainfall
732mm
Sunshine / day
9.9h
Mean relative humidity
78%
Average peak wind
23.4km/h
Seasonal range
14.8°C
Frost days (< 0 °C)
2 d/yr
Hot days (≥ 30 °C)
101 d/yr
Rainy days (≥ 1 mm)
103 d/yr
Annual snowfall
0.4 cm
Average feels-like high
27.0 °C
Average feels-like low
19.1 °C
Average peak gust
39.9 km/h
Tropical nights (≥ 20 °C)
191 d/yr
Solar radiation
17.4 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.3 °C
since 1940
+0.2 °C per decade · r² = 0.35 · 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
40.1 °C
24 September 2005
Coldest day
-9.7 °C
23 December 1989
Wettest day
175 mm
11 September 1971
Windiest day
82.0 km/h
11 September 1961
Strongest gust
139.0 km/h
11 September 1961
Hottest feels-like
43.1 °C
7 June 2019
Coldest feels-like
-17.6 °C
23 December 1989
Snowiest day
9.2 cm
30 January 1949
Sunniest day
13.0 h
4 July 2024
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 | 15.9 °C | -1.8 °C | 34 mm | -18 mm |
| Feb | 19.9 °C | +0.7 °C | 6 mm | -38 mm |
| Mar | 25.2 °C | +3.1 °C | 215 mm | +168 mm |
| Apr | 26.3 °C | +1.2 °C | 14 mm | -38 mm |
| May | 29.4 °C | +1.3 °C | 79 mm | +5 mm |
| Jun | 31.1 °C | +0.7 °C | 95 mm | +25 mm |
| Jul | 31.5 °C | +0.2 °C | 39 mm | -18 mm |
| Aug | 32.8 °C | +1.2 °C | 70 mm | +7 mm |
| Sep | 31.3 °C | +1.2 °C | 80 mm | -27 mm |
| Oct | 29.7 °C | +2.6 °C | 14 mm | -54 mm |
| Nov | 25.9 °C | +3.3 °C | 46 mm | -9 mm |
| Dec | 20.7 °C | +1.4 °C | 47 mm | +3 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 Portland?
Portland has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 21.9 °C and it receives 732 mm of precipitation per year.
What is the hottest day ever recorded in Portland?
The hottest day measured in Portland between 1940 and 2025 was 24 September 2005, reaching 40.1 °C.
What is the coldest day in Portland?
The coldest day measured in Portland between 1940 and 2025 was 23 December 1989, at -9.7 °C.
Does it snow in Portland?
Almost never: Portland sees virtually no snow, with about 2 frost days per year.
Has the climate of Portland warmed?
Yes: Portland warmed by +1.3 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Portland?
The wettest day measured in Portland between 1940 and 2025 was 11 September 1971, with 175 mm of rain in 24 hours.
What was the windiest day in Portland?
The windiest day measured in Portland between 1940 and 2025 was 11 September 1961, with winds reaching 82.0 km/h.
What is the warmest month in Portland?
The warmest month in Portland is August (28.4 °C on average); the coldest is January (13.6 °C).
How much does it rain in Portland?
Portland receives on average 732 mm of precipitation per year, spread over about 103 rainy days.
Is it sunny in Portland?
Portland gets on average 9.9 hours of sunshine per day, roughly 3,614 hours per year over 1940-2025.
What is the biggest single-day snowfall in Portland?
The heaviest 24-hour snowfall measured in Portland between 1940 and 2025 was 30 January 1949, with 9.2 cm.
Are there tropical nights in Portland?
Yes: Portland has on average 191 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Portland?
In Portland, between 1940 and 2025, the highest apparent temperature reached 43.1 °C on 7 June 2019, and the lowest was -17.6 °C on 23 December 1989.
Compare Portland with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Portland