Connecticut has a temperate climate with warm summers and cold winters.
Connecticut has an average annual temperature of 50.4°F across all 18 cities, with approximately 1209 mm of annual precipitation and average humidity of 80%. Temperatures peak in July and drop to their lowest in January, while rainfall is highest during autumn months.
The warmest city is Stamford with average July highs of 83.7°F, while East Hartford is the coldest with average January lows of 15.6°F. Humidity remains high throughout the year, especially during winter months, creating cold and damp conditions. These seasonal patterns make summer pleasant for travel, while winters can bring frost and occasional snowfall.
| Month | 🌤️ | Avg High | Avg Temp | Avg Low | Record High | Record Low | Humid % | Rain (mm) | Wind (m/s) | Solar (kWh/m²) |
|---|---|---|---|---|---|---|---|---|---|---|
| January | ⛅ | 33.8°F | 27.0°F | 19.9°F | 66.2°F | -23.3°F | 87% | 88 | 1.5 | 1.80 |
| February | ⛅ | 36.1°F | 28.8°F | 21.4°F | 70.3°F | -19.1°F | 86% | 80 | 1.6 | 2.70 |
| March | ⛅ | 44.2°F | 36.1°F | 28.0°F | 79.2°F | -12.1°F | 83% | 104 | 1.4 | 3.70 |
| April | ⛅ | 55.8°F | 46.6°F | 37.4°F | 90.9°F | 10.9°F | 79% | 105 | 1.0 | 4.70 |
| May | ⛅ | 66.4°F | 57.2°F | 48.0°F | 89.4°F | 27.9°F | 79% | 104 | 0.8 | 5.50 |
| June | ⛅ | 75.2°F | 66.6°F | 57.7°F | 97.2°F | 36.1°F | 78% | 102 | 0.7 | 5.90 |
| July | ⛅ | 82.0°F | 73.2°F | 64.4°F | 101.7°F | 43.2°F | 75% | 107 | 0.7 | 5.90 |
| August | ⛅ | 81.3°F | 72.3°F | 63.3°F | 102.6°F | 41.5°F | 74% | 104 | 0.7 | 5.30 |
| September | ⛅ | 74.8°F | 65.7°F | 56.3°F | 97.9°F | 31.6°F | 74% | 105 | 0.9 | 4.30 |
| October | ⛅ | 63.0°F | 54.3°F | 45.7°F | 91.6°F | 17.6°F | 77% | 109 | 1.1 | 3.00 |
| November | ⛅ | 50.7°F | 43.2°F | 35.4°F | 78.8°F | 2.1°F | 81% | 96 | 1.1 | 2.00 |
| December | ⛅ | 39.6°F | 33.1°F | 26.6°F | 70.9°F | -7.4°F | 85% | 105 | 1.3 | 1.50 |
Showing average climate conditions across 45 years (1981–2025) · averaged across all 18 cities in Connecticut
🧥 Expect frosty nights and below-freezing temperatures during this Cold Winter period.
🌤️ Conditions are ideal for outdoor activities throughout the day in this Mild Summer.
☔ Moderate Rainfall expected — carry rain gear and plan outdoor activities around these months.
Region-wide monthly averages across 18 cities · 1981–2025 · °F
Temperatures rise steadily from spring, peak in July, and gradually decline through autumn into winter.
These seasonal patterns make summer pleasant for travel, while winters can bring frost and occasional snowfall.
Region-wide monthly rainfall · 1981–2025 · mm/month
💧 Humidity peaks at 87% in January · annual avg 80%
Monthly averages · 1981–2025
Across 45 years, Connecticut's temperature shows a slight warming trend over the past decade. 2012 was the warmest year overall and 1989 the coolest.
The warmest year on record was 2012 (avg: 53.1°F), while the coldest year was 1989 (avg: 48.0°F).
Averaged across all 18 cities in Connecticut · Last 30 years · °F
Averaged across all 18 cities in Connecticut · Last 30 years · mm/year
🔥 hottest · ❄️ coldest · 🌧️ wettest
ℹ️ Values are averages across all 18 cities in Connecticut for each year.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall (mm) | Avg Humidity | Avg Wind |
|---|---|---|---|---|---|---|---|---|
2025 | 59.7°F | 51.4°F | 43.2°F | 101.3°F | 0.5°F | 1026 | 77% | 1.1 m/s |
2024 | 61.0°F | 52.9°F | 44.8°F | 95.0°F | 5.5°F | 1323 | 80% | 1.0 m/s |
2023 | 60.6°F | 52.7°F | 44.8°F | 94.8°F | -11.9°F | 1491 | 82% | 1.0 m/s |
2022 | 60.3°F | 51.8°F | 43.2°F | 98.4°F | -3.6°F | 1116 | 78% | 1.1 m/s |
2021 | 59.9°F | 52.0°F | 44.1°F | 96.6°F | -0.9°F | 1271 | 81% | 1.0 m/s |
2020 | 60.8°F | 52.5°F | 44.2°F | 96.6°F | 0.0°F | 1133 | 79% | 1.1 m/s |
2019 | 58.5°F | 50.5°F | 42.6°F | 93.2°F | -6.0°F | 1363 | 81% | 1.1 m/s |
2018 | 58.5°F | 50.9°F | 43.2°F | 100.9°F | -13.9°F | 1604 | 83% | 1.1 m/s |
2017 | 59.2°F | 51.3°F | 43.3°F | 93.7°F | -4.0°F | 1107 | 80% | 1.1 m/s |
2016 🔥 | 61.2°F | 52.5°F | 43.7°F | 95.7°F | -12.6°F | 940 | 76% | 1.1 m/s |
Showing 1 to 10 of 45 years
All weather data is sourced from NASA POWER (Prediction of Worldwide Energy Resources), a NASA project providing solar and meteorological data for renewable energy, building efficiency, and agricultural research.
