Opportunity climate — normals and trends
Opportunity (United States) has a warm-summer mediterranean continental climate (Dsb) under the Köppen-Geiger classification. Its mean annual temperature is 8.8 °C and it receives 645 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 (21.6 °C on average) and the coldest is January (-2.7 °C). Rainfall peaks in December.
Opportunity averages 118 frost days, 31 hot days (≥ 30 °C) and 112 rainy days per year.
Opportunity has warmed by +2.3 °C between 1940 and 2025, or +0.27 °C per decade. This trend is statistically significant.
The number of frost days there went from about 134 to 102 per year over the period.
The hottest day of the period reached 43.6 °C (on 29 June 2021) and the coldest -30.9 °C (on 1 January 1979).
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
OpportunityWashington
- coords
- 47.65°, -117.24°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
8.8°C
Average daily high
14.0°C
Average daily low
3.7°C
Annual rainfall
645mm
Sunshine / day
9.5h
Mean relative humidity
66%
Average peak wind
13.9km/h
Seasonal range
24.3°C
Frost days (< 0 °C)
118 d/yr
Hot days (≥ 30 °C)
31 d/yr
Rainy days (≥ 1 mm)
112 d/yr
Annual snowfall
119.2 cm
Average feels-like high
11.2 °C
Average feels-like low
0.7 °C
Average peak gust
35.1 km/h
Tropical nights (≥ 20 °C)
1 d/yr
Solar radiation
14.9 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.3 °C
since 1940
+0.3 °C per decade · r² = 0.44 · 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
43.6 °C
29 June 2021
Coldest day
-30.9 °C
1 January 1979
Wettest day
38 mm
24 November 1960
Windiest day
45.7 km/h
17 December 2025
Strongest gust
117.0 km/h
17 December 2025
Hottest feels-like
43.6 °C
29 June 2021
Coldest feels-like
-35.9 °C
1 January 1979
Snowiest day
24.6 cm
18 December 1951
Sunniest day
15.7 h
1 July 2025
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 | 1.7 °C | +1.3 °C | 45 mm | -38 mm |
| Feb | 1.4 °C | -2.3 °C | 80 mm | +18 mm |
| Mar | 10.9 °C | +2.8 °C | 99 mm | +30 mm |
| Apr | 15.6 °C | +2.0 °C | 37 mm | -18 mm |
| May | 20.4 °C | +1.6 °C | 25 mm | -27 mm |
| Jun | 26.0 °C | +3.1 °C | 3 mm | -37 mm |
| Jul | 30.1 °C | +1.5 °C | 8 mm | -5 mm |
| Aug | 29.9 °C | +2.0 °C | 8 mm | -10 mm |
| Sep | 27.2 °C | +4.8 °C | 9 mm | -18 mm |
| Oct | 14.4 °C | +0.1 °C | 65 mm | +14 mm |
| Nov | 8.2 °C | +2.7 °C | 79 mm | -7 mm |
| Dec | 5.9 °C | +4.7 °C | 133 mm | +46 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 Opportunity?
Opportunity has a warm-summer mediterranean continental climate (Köppen Dsb). Over 1940-2025, the average annual temperature is 8.8 °C and it receives 645 mm of precipitation per year.
What is the hottest day ever recorded in Opportunity?
The hottest day measured in Opportunity between 1940 and 2025 was 29 June 2021, reaching 43.6 °C.
What is the coldest day in Opportunity?
The coldest day measured in Opportunity between 1940 and 2025 was 1 January 1979, at -30.9 °C.
Does it snow in Opportunity?
Yes. Opportunity gets on average 119.2 cm of snow per year and has around 118 frost days.
Has the climate of Opportunity warmed?
Yes: Opportunity warmed by +2.3 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Opportunity?
The wettest day measured in Opportunity between 1940 and 2025 was 24 November 1960, with 38 mm of rain in 24 hours.
What was the windiest day in Opportunity?
The windiest day measured in Opportunity between 1940 and 2025 was 17 December 2025, with winds reaching 45.7 km/h.
What is the warmest month in Opportunity?
The warmest month in Opportunity is July (21.6 °C on average); the coldest is January (-2.7 °C).
How much does it rain in Opportunity?
Opportunity receives on average 645 mm of precipitation per year, spread over about 112 rainy days.
Is it sunny in Opportunity?
Opportunity gets on average 9.5 hours of sunshine per day, roughly 3,468 hours per year over 1940-2025.
What is the biggest single-day snowfall in Opportunity?
The heaviest 24-hour snowfall measured in Opportunity between 1940 and 2025 was 18 December 1951, with 24.6 cm.
Are there tropical nights in Opportunity?
Yes: Opportunity has on average 1 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Opportunity?
In Opportunity, between 1940 and 2025, the highest apparent temperature reached 43.6 °C on 29 June 2021, and the lowest was -35.9 °C on 1 January 1979.
Compare Opportunity with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Opportunity