Stillwater climate — normals and trends
Stillwater (United States) has a humid subtropical climate (Cfa) under the Köppen-Geiger classification. Its mean annual temperature is 15.7 °C and it receives 880 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 (28.0 °C on average) and the coldest is January (2.4 °C). Rainfall peaks in May.
Stillwater averages 61 frost days, 92 hot days (≥ 30 °C) and 91 rainy days per year.
Stillwater has warmed by +1.5 °C between 1940 and 2025, or +0.17 °C per decade. This trend is statistically significant.
The number of frost days there went from about 68 to 54 per year over the period.
The hottest day of the period reached 43.9 °C (on 2 August 2012) and the coldest -26.8 °C (on 4 January 1947).
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
StillwaterOklahoma
- coords
- 36.12°, -97.06°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
15.7°C
Average daily high
21.3°C
Average daily low
10.6°C
Annual rainfall
880mm
Sunshine / day
9.6h
Mean relative humidity
65%
Average peak wind
18.3km/h
Seasonal range
25.6°C
Frost days (< 0 °C)
61 d/yr
Hot days (≥ 30 °C)
92 d/yr
Rainy days (≥ 1 mm)
91 d/yr
Annual snowfall
20.6 cm
Average feels-like high
20.5 °C
Average feels-like low
8.7 °C
Average peak gust
38.4 km/h
Tropical nights (≥ 20 °C)
87 d/yr
Solar radiation
17.0 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.5 °C
since 1940
+0.2 °C per decade · r² = 0.28 · 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
43.9 °C
2 August 2012
Coldest day
-26.8 °C
4 January 1947
Wettest day
141 mm
15 November 1964
Windiest day
50.2 km/h
29 April 1984
Strongest gust
104.0 km/h
13 March 2019
Hottest feels-like
47.0 °C
3 August 2011
Coldest feels-like
-32.0 °C
4 January 1947
Snowiest day
22.9 cm
1 February 2011
Sunniest day
14.4 h
22 June 2021
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 | 6.8 °C | -1.2 °C | 26 mm | -12 mm |
| Feb | 9.8 °C | -1.0 °C | 21 mm | -25 mm |
| Mar | 20.7 °C | +4.8 °C | 50 mm | -26 mm |
| Apr | 22.0 °C | +0.7 °C | 284 mm | +175 mm |
| May | 25.5 °C | -0.2 °C | 140 mm | +9 mm |
| Jun | 31.1 °C | +0.4 °C | 232 mm | +129 mm |
| Jul | 33.0 °C | -0.5 °C | 68 mm | +4 mm |
| Aug | 31.1 °C | -2.0 °C | 101 mm | +43 mm |
| Sep | 29.3 °C | +0.6 °C | 29 mm | -52 mm |
| Oct | 25.5 °C | +2.8 °C | 140 mm | +61 mm |
| Nov | 18.7 °C | +3.3 °C | 31 mm | -22 mm |
| Dec | 13.3 °C | +3.5 °C | 1 mm | -42 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 Stillwater?
Stillwater has a humid subtropical climate (Köppen Cfa). Over 1940-2025, the average annual temperature is 15.7 °C and it receives 880 mm of precipitation per year.
What is the hottest day ever recorded in Stillwater?
The hottest day measured in Stillwater between 1940 and 2025 was 2 August 2012, reaching 43.9 °C.
What is the coldest day in Stillwater?
The coldest day measured in Stillwater between 1940 and 2025 was 4 January 1947, at -26.8 °C.
Does it snow in Stillwater?
Yes. Stillwater gets on average 20.6 cm of snow per year and has around 61 frost days.
Has the climate of Stillwater warmed?
Yes: Stillwater warmed by +1.5 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Stillwater?
The wettest day measured in Stillwater between 1940 and 2025 was 15 November 1964, with 141 mm of rain in 24 hours.
What was the windiest day in Stillwater?
The windiest day measured in Stillwater between 1940 and 2025 was 29 April 1984, with winds reaching 50.2 km/h.
What is the warmest month in Stillwater?
The warmest month in Stillwater is July (28.0 °C on average); the coldest is January (2.4 °C).
How much does it rain in Stillwater?
Stillwater receives on average 880 mm of precipitation per year, spread over about 91 rainy days.
Is it sunny in Stillwater?
Stillwater gets on average 9.6 hours of sunshine per day, roughly 3,504 hours per year over 1940-2025.
What is the biggest single-day snowfall in Stillwater?
The heaviest 24-hour snowfall measured in Stillwater between 1940 and 2025 was 1 February 2011, with 22.9 cm.
Are there tropical nights in Stillwater?
Yes: Stillwater has on average 87 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Stillwater?
In Stillwater, between 1940 and 2025, the highest apparent temperature reached 47.0 °C on 3 August 2011, and the lowest was -32.0 °C on 4 January 1947.
Compare Stillwater with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Stillwater