Sterling climate — normals and trends
Sterling (United States) has a hot-summer humid continental climate (Dfa) under the Köppen-Geiger classification. Its mean annual temperature is 9.8 °C and it receives 914 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 (23.4 °C on average) and the coldest is January (-6.1 °C). Rainfall peaks in May.
Sterling averages 122 frost days, 28 hot days (≥ 30 °C) and 111 rainy days per year.
Sterling has warmed by +2.0 °C between 1940 and 2025, or +0.24 °C per decade. This trend is statistically significant.
The number of frost days there went from about 133 to 111 per year over the period.
The hottest day of the period reached 38.9 °C (on 17 August 1988) and the coldest -35.2 °C (on 3 February 1996).
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
SterlingIllinois
- coords
- 41.79°, -89.70°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
9.8°C
Average daily high
14.6°C
Average daily low
5.0°C
Annual rainfall
914mm
Sunshine / day
8.7h
Mean relative humidity
71%
Average peak wind
20.0km/h
Seasonal range
29.5°C
Frost days (< 0 °C)
122 d/yr
Hot days (≥ 30 °C)
28 d/yr
Rainy days (≥ 1 mm)
111 d/yr
Annual snowfall
67.3 cm
Average feels-like high
12.6 °C
Average feels-like low
2.1 °C
Average peak gust
38.0 km/h
Tropical nights (≥ 20 °C)
28 d/yr
Solar radiation
15.0 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.0 °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
38.9 °C
17 August 1988
Coldest day
-35.2 °C
3 February 1996
Wettest day
80 mm
10 October 1954
Windiest day
55.2 km/h
9 March 2002
Strongest gust
100.8 km/h
6 April 1997
Hottest feels-like
43.7 °C
13 July 1995
Coldest feels-like
-41.0 °C
3 February 1996
Snowiest day
25.5 cm
15 December 1987
Sunniest day
14.3 h
2 July 2022
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 | -1.1 °C | +0.9 °C | 41 mm | -6 mm |
| Feb | 0.7 °C | +0.1 °C | 18 mm | -25 mm |
| Mar | 13.0 °C | +5.3 °C | 118 mm | +44 mm |
| Apr | 16.5 °C | +1.2 °C | 94 mm | -8 mm |
| May | 21.9 °C | +0.5 °C | 76 mm | -29 mm |
| Jun | 29.1 °C | +2.6 °C | 100 mm | -3 mm |
| Jul | 29.7 °C | +1.4 °C | 121 mm | +36 mm |
| Aug | 27.3 °C | -0.1 °C | 87 mm | +5 mm |
| Sep | 27.3 °C | +3.5 °C | 32 mm | -52 mm |
| Oct | 20.6 °C | +3.4 °C | 40 mm | -34 mm |
| Nov | 10.0 °C | +1.6 °C | 54 mm | -9 mm |
| Dec | 0.4 °C | -0.6 °C | 55 mm | +1 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 Sterling?
Sterling has a hot-summer humid continental climate (Köppen Dfa). Over 1940-2025, the average annual temperature is 9.8 °C and it receives 914 mm of precipitation per year.
What is the hottest day ever recorded in Sterling?
The hottest day measured in Sterling between 1940 and 2025 was 17 August 1988, reaching 38.9 °C.
What is the coldest day in Sterling?
The coldest day measured in Sterling between 1940 and 2025 was 3 February 1996, at -35.2 °C.
Does it snow in Sterling?
Yes. Sterling gets on average 67.3 cm of snow per year and has around 122 frost days.
Has the climate of Sterling warmed?
Yes: Sterling warmed by +2.0 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Sterling?
The wettest day measured in Sterling between 1940 and 2025 was 10 October 1954, with 80 mm of rain in 24 hours.
What was the windiest day in Sterling?
The windiest day measured in Sterling between 1940 and 2025 was 9 March 2002, with winds reaching 55.2 km/h.
What is the warmest month in Sterling?
The warmest month in Sterling is July (23.4 °C on average); the coldest is January (-6.1 °C).
How much does it rain in Sterling?
Sterling receives on average 914 mm of precipitation per year, spread over about 111 rainy days.
Is it sunny in Sterling?
Sterling 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 Sterling?
The heaviest 24-hour snowfall measured in Sterling between 1940 and 2025 was 15 December 1987, with 25.5 cm.
Are there tropical nights in Sterling?
Yes: Sterling has on average 28 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Sterling?
In Sterling, between 1940 and 2025, the highest apparent temperature reached 43.7 °C on 13 July 1995, and the lowest was -41.0 °C on 3 February 1996.
Compare Sterling with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Sterling