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South Windsor, Connecticut climate
Cfa Humid subtropical
South Windsor has a seasonal cool-temperate climate (Humid subtropical, Köppen Cfa). The hottest month is July with an average daily high near 27°C, while the coldest is January averaging around −7°C at night. Precipitation is fairly even year-round, totalling about 1251 mm. Winters bring significant snowfall (99 cm of snow per year on average).
Temperature & precipitation
Daily high–low temperature range with the monthly average, plus monthly precipitation split into rain and snow · 1991–2020 normals · hover a month for the exact figuresClear vs cloudy days
Share of days each month that are clear, partly cloudy or cloudy · 1991–2020 · hover a month for the day countsSouth Windsor climate normals (1991–2020)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 2 | 3 | 7 | 14 | 20 | 24 | 27 | 26 | 23 | 16 | 10 | 5 |
| Avg temp (°C) | −3 | −2 | 2 | 9 | 14 | 19 | 22 | 21 | 17 | 11 | 6 | 0 |
| Avg low (°C) | −7 | −6 | −2 | 3 | 9 | 14 | 17 | 16 | 12 | 6 | 1 | −4 |
| Precipitation (mm) | 93 | 76 | 111 | 107 | 95 | 115 | 102 | 109 | 114 | 116 | 99 | 114 |
| Snowfall (cm) | 21 | 36 | 16 | 4 | — | — | — | — | — | 1 | 3 | 18 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Avg high (°C) | 2 | 3 | 7 | 14 | 20 | 24 |
| Avg temp (°C) | −3 | −2 | 2 | 9 | 14 | 19 |
| Avg low (°C) | −7 | −6 | −2 | 3 | 9 | 14 |
| Precipitation (mm) | 93 | 76 | 111 | 107 | 95 | 115 |
| Snowfall (cm) | 21 | 36 | 16 | 4 | — | — |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Avg high (°C) | 27 | 26 | 23 | 16 | 10 | 5 |
| Avg temp (°C) | 22 | 21 | 17 | 11 | 6 | 0 |
| Avg low (°C) | 17 | 16 | 12 | 6 | 1 | −4 |
| Precipitation (mm) | 102 | 109 | 114 | 116 | 99 | 114 |
| Snowfall (cm) | — | — | — | 1 | 3 | 18 |
How often — frequency of weather events
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 8 | 7 | 9 | 9 | 11 | 10 | 9 | 9 | 9 | 9 | 8 | 10 |
| Days with high ≥ 32°C (days) | — | — | — | 0.0 | 0.1 | 0.3 | 1 | 0.6 | 0.1 | — | — | — |
| Days with low ≤ 0°C (days) | 22 | 21 | 20 | 6 | 0.2 | — | — | — | 0.0 | 2 | 12 | 23 |
| Days with snowfall ≥ 2.5 cm (days) | 2 | 2 | 2 | 0.3 | — | — | — | — | — | 0.0 | 0.3 | 2 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 8 | 7 | 9 | 9 | 11 | 10 |
| Days with high ≥ 32°C (days) | — | — | — | 0.0 | 0.1 | 0.3 |
| Days with low ≤ 0°C (days) | 22 | 21 | 20 | 6 | 0.2 | — |
| Days with snowfall ≥ 2.5 cm (days) | 2 | 2 | 2 | 0.3 | — | — |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 9 | 9 | 9 | 9 | 8 | 10 |
| Days with high ≥ 32°C (days) | 1 | 0.6 | 0.1 | — | — | — |
| Days with low ≤ 0°C (days) | — | — | 0.0 | 2 | 12 | 23 |
| Days with snowfall ≥ 2.5 cm (days) | — | — | — | 0.0 | 0.3 | 2 |
Sky & atmosphere
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cloud cover (%) | 64 | 61 | 62 | 63 | 63 | 61 | 57 | 54 | 53 | 57 | 61 | 63 |
| Clear days (≤ 30% cloud) | 5 | 6 | 6 | 6 | 5 | 5 | 7 | 8 | 9 | 8 | 6 | 5 |
| Partly cloudy days (30–70%) | 12 | 10 | 11 | 10 | 12 | 12 | 13 | 12 | 10 | 10 | 10 | 12 |
| Cloudy days (≥ 70%) | 14 | 13 | 14 | 14 | 15 | 13 | 11 | 11 | 11 | 13 | 14 | 14 |
| Relative humidity (%) | 89 | 88 | 84 | 79 | 78 | 77 | 73 | 72 | 73 | 78 | 82 | 87 |
| Wind speed (mph) | 0.9 | 1.2 | 0.9 | 0.3 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.2 | 0.2 | 0.3 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 64 | 61 | 62 | 63 | 63 | 61 |
| Clear days (≤ 30% cloud) | 5 | 6 | 6 | 6 | 5 | 5 |
| Partly cloudy days (30–70%) | 12 | 10 | 11 | 10 | 12 | 12 |
| Cloudy days (≥ 70%) | 14 | 13 | 14 | 14 | 15 | 13 |
| Relative humidity (%) | 89 | 88 | 84 | 79 | 78 | 77 |
| Wind speed (mph) | 0.9 | 1.2 | 0.9 | 0.3 | 0.1 | 0.1 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 57 | 54 | 53 | 57 | 61 | 63 |
| Clear days (≤ 30% cloud) | 7 | 8 | 9 | 8 | 6 | 5 |
| Partly cloudy days (30–70%) | 13 | 12 | 10 | 10 | 10 | 12 |
| Cloudy days (≥ 70%) | 11 | 11 | 11 | 13 | 14 | 14 |
| Relative humidity (%) | 73 | 72 | 73 | 78 | 82 | 87 |
| Wind speed (mph) | 0.1 | 0.1 | 0.1 | 0.2 | 0.2 | 0.3 |
Methodology & sources
Temperature & precipitation — the official 1991–2020 climate normals from NOAA's U.S. Climate Normals, measured at Storrs (NOAA GHCN station USC00068138), about 33 km from the city centre.
Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.