Norwalk has a temperate climate with warm summers and freezing winters.
Temperatures peak in July and drop to their lowest in January, while rainfall is highest during winter months.
Humidity remains high throughout the year, especially during winter months, creating cold and damp conditions.
| Month | 🌤️ | High | Low | Avg | Humid % | Rain (mm) | Wind (m/s) | Solar (kWh/m²) |
|---|---|---|---|---|---|---|---|---|
| January | ☔ | 51.1°F | 12.1°F | 31.6°F | 84% | 90 | 3.6 | 1.78 |
| February | ☔ | 49.3°F | 13.3°F | 31.3°F | 83% | 82 | 3.4 | 2.65 |
| March | ☔ | 57.8°F | 19.8°F | 38.8°F | 81% | 107 | 3.1 | 3.73 |
| April | ☔ | 67.2°F | 31.3°F | 49.2°F | 80% | 106 | 2.6 | 4.68 |
| May | ☔ | 75.8°F | 41.6°F | 58.7°F | 81% | 102 | 2.1 | 5.42 |
| June | ☔ | 82.6°F | 50.9°F | 66.8°F | 80% | 99 | 2.0 | 5.91 |
| July | ☔ | 87.3°F | 60.4°F | 73.9°F | 78% | 102 | 1.9 | 5.91 |
| August | ☔ | 86.4°F | 59.7°F | 73.1°F | 76% | 102 | 2.1 | 5.25 |
| September | ☔ | 82.8°F | 51.9°F | 67.3°F | 75% | 101 | 2.5 | 4.25 |
| October | ☔ | 74.6°F | 40.8°F | 57.7°F | 76% | 107 | 3.0 | 3.01 |
| November | ☔ | 65.0°F | 29.9°F | 47.5°F | 79% | 95 | 3.2 | 2.02 |
| December | ☔ | 56.4°F | 19.9°F | 38.2°F | 82% | 108 | 3.4 | 1.51 |
Showing average climate conditions across 45 years (1981–2025)
🧥 Pack heavy layers and prepare for snow — this is a Severe Winter destination.
🌤️ Early mornings and evenings are most comfortable during this Hot Summer season.
☔ Moderate Rainfall expected — carry rain gear and plan outdoor activities around these months.
Monthly averages · 1981–2025 climate normals · °F
Temperatures rise steadily from spring, peak in July, and gradually decline through autumn into winter.
These seasonal patterns make summer ideal for outdoor activities, while winters bring freezing conditions and heavy snowfall.
Monthly rainfall · 1981–2025 seasonal trends · mm/month
Monthly averages · 1981–2025
💧 Humidity peaks at 84% in January · annual avg 80%
The warmest year in Norwalk's recorded history was 2024 (avg: 55.9°F), while the coldest was 1984 (avg: 50.0°F).
Average annual high/low · Last 10 years · °F
Total annual precipitation · Last 10 years · mm/year
| Year | Min Temp | Avg Temp | Max Temp | Rainfall (mm) | Avg Humidity | Avg Wind |
|---|---|---|---|---|---|---|
2025 | 38.3°F | 54.9°F | 71.2°F | 954 | 77% | 2.9 m/s |
2024 | 39.6°F | 55.9°F | 72.1°F | 1316 | 80% | 2.7 m/s |
2023 | 39.0°F | 55.2°F | 71.4°F | 1403 | 80% | 2.6 m/s |
2022 | 37.4°F | 54.9°F | 72.1°F | 1121 | 78% | 2.8 m/s |
2021 | 38.3°F | 54.3°F | 70.3°F | 1241 | 81% | 2.7 m/s |
2020 | 37.0°F | 53.6°F | 70.3°F | 1184 | 80% | 2.8 m/s |
2019 | 35.6°F | 53.1°F | 70.5°F | 1419 | 81% | 2.7 m/s |
2018 🌧️ | 36.3°F | 53.4°F | 70.7°F | 1668 | 83% | 2.8 m/s |
2017 | 36.5°F | 53.8°F | 71.1°F | 1179 | 80% | 2.8 m/s |
2016 | 36.5°F | 54.5°F | 72.5°F | 984 | 77% | 2.8 m/s |
Showing 1 to 10 of 45 years
Based on 45 years of data (1981–2025), July is typically the hottest month in Norwalk, Connecticut, with average high temperatures around 87.3°F.
January is the coldest month in Norwalk, with average low temperatures around 12.1°F.
December receives the most rainfall with approximately 108 mm, while February is the driest with 82 mm.
The highest recorded temperature was 97.0°F in July 2010. This is part of the historical record spanning 1981–2025.
The lowest recorded temperature was 1.2°F in February 2016.
This page covers 45 years of climate data from 1981 to 2025. As new data is added to the database the page automatically reflects the updated coverage.
Norwalk receives the most sunlight in June with an average solar radiation of 5.91 kWh/m²/day. This solar radiation data, sourced from NASA POWER, is useful for solar energy planning and agriculture in Connecticut.
All climate data is sourced from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite and model data. It provides monthly averages for temperature, precipitation, humidity, wind speed, and solar radiation.
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.
