Photo: Carol M. Highsmith · Public domainWet weather: 49 inches of rain and melted snow a year in East Haddam, more than in 80% of U.S. towns
Nights in January average 20°. In July, afternoons here are cooler than in 74% of U.S. towns. December has warmed most since 1901–2000, part of a 2.0° rise. Seedlings are safe outdoors from about April 14, with the first autumn frost due around October 24.
A year in East Haddam at a glance
Each month’s typical high and low, and what it brings.
What stands out about East Haddam’s climate
Compared with towns across the U.S., with East Haddam’s place in Connecticut beside it.
What a year in East Haddam feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 192 frost-free days a year
In half of years the last 32° night comes by April 14 and the first by October 24. Frost and day counts come from NOAA’s station at Norwich Public Utility Plt, CT, 17 miles from the town’s center, 350 ft lower.
The 2023 USDA map puts East Haddam’s center in zone 6b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −2°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 28 inches of snow a winter
Snow, measured at Norwich Public Utility Plt, CT, falls mostly in January. Precipitation (rain plus melted snow) adds up to 49 inches a year; October is the wettest month and February the driest. Rain or snow falls on about 120 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in East Haddam
87% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Norwich Public Utility Plt, CT.
Living with East Haddam’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
192 frost-free days in zone 6b. The last frost comes by Apr 14 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 24.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August, September and October. 120 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in East Haddam from natural hazards, river flooding is the largest share (74%); heat waves, cold waves, winter storms and ice storms together are 3%. Normals are averages; the hazards page covers the extremes.
Natural hazards →East Haddam and its neighbors
Every town next door is within a degree of East Haddam in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like East Haddam’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| East Haddam, CT | 20° | 83° | 49" | 28" |
| Bangor, PA | 19° | 84° | 50" | 23" |
| Bridgeport, WV | 23° | 84° | 47" | 24" |
| New Castle, IN | 19° | 84° | 44" | 25" |
| Manchester, MD | 22° | 84° | 47" | 34" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in East Haddam averaged 2.0° warmer than the 1900s. The biggest change is in December (+3.6°).
A bigger shift than in 90% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How East Haddam compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with East Haddam’s place among Connecticut’s.
East Haddam weather by month
Highs, lows and precipitation from NOAA’s grid at East Haddam’s center; snow, wet days and snow on the ground from Norwich Public Utility Plt, CT. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 37° | 20° | 3.8" | 9.0" | 11 | 10 | 20° – 35° |
| February | 40° | 21° | 3.0" | 7.1" | 10 | 10 | 17° – 37° |
| March | 47° | 28° | 4.3" | 5.0" | 10 | 4 | 32° – 46° |
| April | 59° | 37° | 4.3" | 0.8" | 11 | 0 | 44° – 52° |
| May | 69° | 47° | 3.7" | 0.0" | 11 | 0 | 53° – 62° |
| June | 77° | 56° | 4.3" | 0.0" | 10 | 0 | 64° – 70° |
| July | 83° | 62° | 3.5" | 0.0" | 9 | 0 | 68° – 76° |
| August | 81° | 61° | 4.1" | 0.0" | 9 | 0 | 67° – 75° |
| September | 74° | 53° | 4.3" | 0.0" | 9 | 0 | 61° – 68° |
| October | 63° | 43° | 4.8" | 0.0" | 10 | 0 | 49° – 59° |
| November | 52° | 34° | 4.1" | 0.3" | 9 | 0 | 38° – 47° |
| December | 42° | 25° | 4.6" | 5.6" | 11 | 6 | 27° – 44° |
| Year | 60° | 40° | 48.8" | 27.8" | 120 | 30 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 17° to 37°. June is the most reliable, staying within 5°.
Where East Haddam’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at East Haddam’s center.
- Snow: Norwich Public Utility Plt, CT.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Norwich Public Utility Plt, CT, 17 miles from the town’s center, 350 ft lower; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about East Haddam’s climate
What is the weather like in East Haddam?
A typical July afternoon reaches 83°, a January night drops to 20°, and about 28 inches of snow falls in a normal winter. Colder January nights than 60% of U.S. towns; cooler July afternoons than 74% of U.S. towns.
How cold does it get in East Haddam in winter?
January nights average 20°. About 124 nights a year reach 32° or below and 2 reach 0° or below. In the coldest January of the last 30 years the month averaged 20°.
How much snow does East Haddam get?
About 28 inches in a normal winter at Norwich Public Utility Plt, CT, most of it in January, with snow on the ground about 30 days a year.
How hot does it get in East Haddam?
July, with a typical high of 83° and a low of 62°. About 14 days a year reach 90° (Norwich Public Utility Plt, CT).
When is the first and last frost in East Haddam?
In half of years the last spring frost (32°) comes by April 14 and the first fall frost by October 24, about 192 frost-free days, at Norwich Public Utility Plt, CT.
What growing zone is East Haddam in?
Zone 6b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −2°.
What is the best time of year to visit East Haddam?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, July, August, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is East Haddam getting warmer?
Yes: 1991–2020 averaged 2.0° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 90% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in East Haddam.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.