Connecticut Historical Weather Data & Climate

Historical Climate Data for 18 Cities  •  1981–2025

°F / °C

Connecticut Climate Overview

Connecticut has an average annual temperature of 51.1°F (across all 18 cities) with approximately 1191 mm of annual precipitation and average humidity of 80%. The warmest city is Danbury with average July highs of 92.7°F, while East Hartford is the coldest with average January lows of -3.3°F. This page covers 45 years of NASA POWER climate data (1981–2025) including temperature, rainfall, humidity, wind speed, and solar radiation.

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Quick Climate Facts

(1981 – 2025)
Hottest City
🔥
Danbury
Jul High: 92.7°F
Coldest City
❄️
East Hartford
Jan Low: -3.3°F
Wettest City
💧
East Hartford
1199 mm/yr
Driest City
🏜️
Meriden
1173 mm/yr
Hottest Month
🌞
Jul
Avg High: 90.9°F
Coldest Month
🧊
Jan
Avg Low: 2.8°F
Cities With Data
🏙️
18
cities in Connecticut
Data Coverage
📅
45 yrs
1981 – 2025

🏙️ Cities in Connecticut — Weather History

📅 Connecticut Monthly Climate Averages

🌡️ State-Wide Monthly Temperature

Average across all 18 cities · 1981–2025 · °F

🌧️ Monthly Precipitation

State-wide average · mm/month

📖 Connecticut Seasonal Climate Guide

Jul is typically the warmest month across Connecticut with average highs around 90.9°F, while Jan is the coldest with average lows near 2.8°F. Oct is the wettest month with approximately 109 mm of rainfall on average.
MonthMax TempMin TempAvg Temp Rain (mm)HumidityWind (m/s)Solar (kWh/m²)
Jan 51.3°F 2.8°F 27.1°F 87 87% 1.5 1.80
Feb 51.4°F 5.4°F 28.4°F 81 86% 1.6 2.70
Mar 61.3°F 13.3°F 37.4°F 102 83% 1.4 3.70
Apr 72°F 26.8°F 49.5°F 105 79% 1.0 4.70
May 80.1°F 37.2°F 58.6°F 102 79% 0.8 5.50
Jun 86.4°F 46.8°F 66.6°F 102 78% 0.7 5.90
Jul 90.9°F 55.8°F 73.4°F 109 75% 0.7 5.90
Aug 90.1°F 54°F 72.1°F 102 74% 0.7 5.30
Sep 86.5°F 44.6°F 65.7°F 105 74% 0.9 4.30
Oct 76.8°F 32.9°F 54.9°F 109 77% 1.1 3.00
Nov 66.4°F 23.2°F 44.8°F 96 81% 1.1 2.00
Dec 56.3°F 12°F 34.2°F 105 85% 1.3 1.50

📈 Connecticut Yearly Climate Trends

🌡️ Annual Temperature Trend

State-wide avg annual high & low · Last 10 years

📈 Connecticut Long-Term Climate Trends (1981–2025)

This chart shows how Connecticut's average temperatures have shifted across 45 years. Use the range buttons to focus on recent decades or view the full historical record. Data is averaged across all 18 cities in the state.

🌧️ Annual Precipitation Trend

State-wide avg annual precipitation · Last 10 years · mm/year

🔗 Explore Cities in Connecticut

Browse detailed weather history, monthly averages, and 45-year climate trends for every city in Connecticut.

Looking for another state? 🇺🇸 Explore All US States & Cities →

❓ Frequently Asked Questions

What is the hottest city in Connecticut?
Danbury is the hottest city in Connecticut with an average July high of 92.7°F based on 45 years of data. View Danbury weather history →
What is the coldest city in Connecticut?
East Hartford is the coldest city with average January lows of -3.3°F. View East Hartford weather history →
Which city in Connecticut gets the most rain?
East Hartford is the wettest city in Connecticut with approximately 1199 mm of annual precipitation on average. View East Hartford weather history →
What is the warmest month in Connecticut?
Jul is the warmest month across Connecticut, with state-wide average highs of 90.9°F and average lows of 55.8°F.
How many cities in Connecticut have weather data?
TownPillar has historical weather data for 18 cities in Connecticut, covering 45 years of NASA POWER climate records from 1981 to 2025.
Which month has the most sunshine in Connecticut?
Jul is the sunniest month across Connecticut with an average solar radiation of 5.90 kWh/m²/day state-wide. This solar radiation data from NASA POWER is useful for solar energy planning, agriculture, and understanding seasonal sunshine availability.
Where does this climate data come from?
All data is sourced from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis data. It includes monthly temperature, precipitation, humidity, wind speed, and solar radiation at 0.5° × 0.625° spatial resolution.

📚 Data Source

All weather data is sourced from NASA POWER (Prediction of Worldwide Energy Resources). Data covers 45 years (1981–2025) across 18 cities in Connecticut at monthly temporal resolution.