Climate averages 1991–2020
Hartford weather
in May.
A mild, moderately wet month: the 5th warmest and the joint 2nd driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
May is a mild month in Hartford: daytime highs average 20.4°C and nights cool to about 9.7°C. By daytime temperature it is the 5th warmest of the 12 months.
Expect about 84 mm of rain on roughly 11 days, which makes May a moderately wet month (the joint 2nd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 14 h 31 min on an average May day.
The nearest other city in this atlas is New Britain (14 km away). In May its highs average 20.2°C, about as warm as Hartford, with 84 mm of rain.
Among the 498 cities listed in the United States, Hartford ranks joint 359th of 498 for the warmest May highs and joint 238th of 498 for the driest May (rainfall, lowest first). The mean May high of those 498 cities is 23.8°C; Hartford is 3.4°C cooler than that mean.
From May to June, average highs rise by 5.0°C to 25.4°C, and monthly rainfall rises from 84 mm to 96 mm.
The annual picture
May in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Hartford climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 2.0°C-6.9°C | -6.9°C | 84 | 9.3 | 9.510 h |
| February | 3.6°C-6.1°C | -6.1°C | 76 | 8.7 | 10.611 h |
| March | 8.0°C-2.1°C | -2.1°C | 103 | 10.5 | 11.912 h |
| April | 14.7°C3.8°C | 3.8°C | 91 | 10.8 | 13.313 h |
| May, selected | 20.4°C9.7°C | 9.7°C | 84 | 10.9 | 14.515 h |
| June | 25.4°C15.1°C | 15.1°C | 96 | 11.5 | 15.215 h |
| July | 28.6°C18.4°C | 18.4°C | 89 | 10.6 | 14.915 h |
| August | 27.6°C17.8°C | 17.8°C | 100 | 10.1 | 13.914 h |
| September | 23.4°C13.9°C | 13.9°C | 97 | 8.5 | 12.513 h |
| October | 16.6°C7.7°C | 7.7°C | 103 | 9.2 | 11.111 h |
| November | 10.3°C2.0°C | 2.0°C | 84 | 8.5 | 9.910 h |
| December | 4.7°C-3.1°C | -3.1°C | 104 | 10.0 | 9.29 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
May in nearby cities
- New Britain in MayUnited States · 14 kmHigh 20.2°C · Low 9.8°C · 84 mm rain
- Waterbury in MayUnited States · 38 kmHigh 20.0°C · Low 10.3°C · 87 mm rain
- Springfield (Massachusetts), United States in MayUnited States · 38 kmHigh 19.9°C · Low 9.5°C · 83 mm rain
- New Haven in MayUnited States · 55 kmHigh 18.4°C · Low 10.6°C · 98 mm rain
- Danbury in MayUnited States · 76 kmHigh 19.9°C · Low 10.2°C · 99 mm rain
- Bridgeport in MayUnited States · 77 kmHigh 19.0°C · Low 10.9°C · 92 mm rain
- Worcester, United States in MayUnited States · 92 kmHigh 19.2°C · Low 9.2°C · 82 mm rain
- Norwalk in MayUnited States · 94 kmHigh 19.5°C · Low 11.2°C · 85 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Hartford) is explained once on the Hartford year overview and on the Sources, method and limits page.
New Britain lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.