Gresham climate — normals and trends
Gresham (United States) has a warm-summer mediterranean climate (Csb) under the Köppen-Geiger classification. Its mean annual temperature is 11.2 °C and it receives 1,604 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 (19.4 °C on average) and the coldest is January (3.9 °C). Rainfall peaks in December.
Gresham averages 37 frost days, 22 hot days (≥ 30 °C) and 155 rainy days per year.
Gresham has warmed by +1.6 °C between 1940 and 2025, or +0.19 °C per decade. This trend is statistically significant.
The number of frost days there went from about 47 to 27 per year over the period.
The hottest day of the period reached 47.2 °C (on 28 June 2021) and the coldest -21.3 °C (on 31 January 1950).
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
GreshamOregon
- coords
- 45.50°, -122.43°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
11.2°C
Average daily high
16.3°C
Average daily low
6.7°C
Annual rainfall
1,604mm
Sunshine / day
8.7h
Mean relative humidity
75%
Average peak wind
12.6km/h
Seasonal range
15.5°C
Frost days (< 0 °C)
37 d/yr
Hot days (≥ 30 °C)
22 d/yr
Rainy days (≥ 1 mm)
155 d/yr
Annual snowfall
47.8 cm
Average feels-like high
14.8 °C
Average feels-like low
4.5 °C
Average peak gust
33.2 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
13.7 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.6 °C
since 1940
+0.2 °C per decade · r² = 0.41 · 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
47.2 °C
28 June 2021
Coldest day
-21.3 °C
31 January 1950
Wettest day
108 mm
25 November 1999
Windiest day
46.0 km/h
14 November 1981
Strongest gust
115.9 km/h
14 December 2006
Hottest feels-like
45.8 °C
28 June 2021
Coldest feels-like
-26.2 °C
31 January 1950
Snowiest day
17.7 cm
31 January 1969
Sunniest day
15.3 h
17 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 | 8.5 °C | +1.4 °C | 109 mm | -124 mm |
| Feb | 8.7 °C | -0.8 °C | 207 mm | +26 mm |
| Mar | 13.0 °C | +0.9 °C | 258 mm | +80 mm |
| Apr | 17.8 °C | +2.7 °C | 72 mm | -57 mm |
| May | 20.0 °C | +1.2 °C | 51 mm | -37 mm |
| Jun | 24.4 °C | +2.3 °C | 34 mm | -24 mm |
| Jul | 28.7 °C | +2.2 °C | 2 mm | -14 mm |
| Aug | 28.5 °C | +2.0 °C | 26 mm | +1 mm |
| Sep | 24.9 °C | +1.7 °C | 35 mm | -29 mm |
| Oct | 16.2 °C | -0.5 °C | 139 mm | -7 mm |
| Nov | 12.0 °C | +1.5 °C | 195 mm | -42 mm |
| Dec | 10.5 °C | +3.2 °C | 390 mm | +144 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 Gresham?
Gresham has a warm-summer mediterranean climate (Köppen Csb). Over 1940-2025, the average annual temperature is 11.2 °C and it receives 1,604 mm of precipitation per year.
What is the hottest day ever recorded in Gresham?
The hottest day measured in Gresham between 1940 and 2025 was 28 June 2021, reaching 47.2 °C.
What is the coldest day in Gresham?
The coldest day measured in Gresham between 1940 and 2025 was 31 January 1950, at -21.3 °C.
Does it snow in Gresham?
Yes. Gresham gets on average 47.8 cm of snow per year and has around 37 frost days.
Has the climate of Gresham warmed?
Yes: Gresham warmed by +1.6 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Gresham?
The wettest day measured in Gresham between 1940 and 2025 was 25 November 1999, with 108 mm of rain in 24 hours.
What was the windiest day in Gresham?
The windiest day measured in Gresham between 1940 and 2025 was 14 November 1981, with winds reaching 46.0 km/h.
What is the warmest month in Gresham?
The warmest month in Gresham is July (19.4 °C on average); the coldest is January (3.9 °C).
How much does it rain in Gresham?
Gresham receives on average 1,604 mm of precipitation per year, spread over about 155 rainy days.
Is it sunny in Gresham?
Gresham 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 Gresham?
The heaviest 24-hour snowfall measured in Gresham between 1940 and 2025 was 31 January 1969, with 17.7 cm.
Are there tropical nights in Gresham?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Gresham.
What was the most extreme apparent temperature in Gresham?
In Gresham, between 1940 and 2025, the highest apparent temperature reached 45.8 °C on 28 June 2021, and the lowest was -26.2 °C on 31 January 1950.
Compare Gresham with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Gresham