South Windsor climate — normals and trends
South Windsor (United States) has a hot-summer humid continental climate (Dfa) under the Köppen-Geiger classification. Its mean annual temperature is 10.2 °C and it receives 1,096 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 (22.9 °C on average) and the coldest is January (-2.5 °C). Rainfall peaks in August.
South Windsor averages 110 frost days, 23 hot days (≥ 30 °C) and 120 rainy days per year.
South Windsor has warmed by +1.7 °C between 1940 and 2025, or +0.20 °C per decade. This trend is statistically significant.
The number of frost days there went from about 119 to 101 per year over the period.
The hottest day of the period reached 39.7 °C (on 18 July 2012) and the coldest -29.4 °C (on 13 February 1967).
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
South WindsorConnecticut
- coords
- 41.82°, -72.62°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
10.2°C
Average daily high
15.2°C
Average daily low
5.6°C
Annual rainfall
1,096mm
Sunshine / day
8.7h
Mean relative humidity
69%
Average peak wind
16.1km/h
Seasonal range
25.4°C
Frost days (< 0 °C)
110 d/yr
Hot days (≥ 30 °C)
23 d/yr
Rainy days (≥ 1 mm)
120 d/yr
Annual snowfall
90.9 cm
Average feels-like high
13.4 °C
Average feels-like low
2.9 °C
Average peak gust
39.2 km/h
Tropical nights (≥ 20 °C)
19 d/yr
Solar radiation
14.4 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.7 °C
since 1940
+0.2 °C per decade · r² = 0.43 · 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
39.7 °C
18 July 2012
Coldest day
-29.4 °C
13 February 1967
Wettest day
127 mm
19 September 1972
Windiest day
49.1 km/h
25 November 1950
Strongest gust
136.4 km/h
25 November 1950
Hottest feels-like
43.9 °C
26 June 1952
Coldest feels-like
-34.0 °C
13 February 1967
Snowiest day
30.6 cm
16 February 1958
Sunniest day
14.7 h
17 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 | 1.1 °C | -0.6 °C | 42 mm | -44 mm |
| Feb | 2.8 °C | -0.3 °C | 77 mm | -3 mm |
| Mar | 11.4 °C | +3.5 °C | 108 mm | +10 mm |
| Apr | 16.0 °C | +1.7 °C | 85 mm | -8 mm |
| May | 19.8 °C | -0.4 °C | 211 mm | +118 mm |
| Jun | 26.1 °C | +0.9 °C | 62 mm | -26 mm |
| Jul | 29.3 °C | +1.2 °C | 115 mm | +25 mm |
| Aug | 27.0 °C | 0.0 °C | 59 mm | -41 mm |
| Sep | 24.3 °C | +1.4 °C | 73 mm | -16 mm |
| Oct | 17.2 °C | +0.3 °C | 96 mm | +5 mm |
| Nov | 9.9 °C | -0.5 °C | 55 mm | -38 mm |
| Dec | 2.7 °C | -1.4 °C | 82 mm | -16 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 South Windsor?
South Windsor has a hot-summer humid continental climate (Köppen Dfa). Over 1940-2025, the average annual temperature is 10.2 °C and it receives 1,096 mm of precipitation per year.
What is the hottest day ever recorded in South Windsor?
The hottest day measured in South Windsor between 1940 and 2025 was 18 July 2012, reaching 39.7 °C.
What is the coldest day in South Windsor?
The coldest day measured in South Windsor between 1940 and 2025 was 13 February 1967, at -29.4 °C.
Does it snow in South Windsor?
Yes. South Windsor gets on average 90.9 cm of snow per year and has around 110 frost days.
Has the climate of South Windsor warmed?
Yes: South Windsor warmed by +1.7 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in South Windsor?
The wettest day measured in South Windsor between 1940 and 2025 was 19 September 1972, with 127 mm of rain in 24 hours.
What was the windiest day in South Windsor?
The windiest day measured in South Windsor between 1940 and 2025 was 25 November 1950, with winds reaching 49.1 km/h.
What is the warmest month in South Windsor?
The warmest month in South Windsor is July (22.9 °C on average); the coldest is January (-2.5 °C).
How much does it rain in South Windsor?
South Windsor receives on average 1,096 mm of precipitation per year, spread over about 120 rainy days.
Is it sunny in South Windsor?
South Windsor 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 South Windsor?
The heaviest 24-hour snowfall measured in South Windsor between 1940 and 2025 was 16 February 1958, with 30.6 cm.
Are there tropical nights in South Windsor?
Yes: South Windsor has on average 19 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in South Windsor?
In South Windsor, between 1940 and 2025, the highest apparent temperature reached 43.9 °C on 26 June 1952, and the lowest was -34.0 °C on 13 February 1967.
Compare South Windsor with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around South Windsor