Riders Mills Historic District · Photo: UtsukushiHikariNY · CC BY-SA 4.0Nights turn raw in Chatham each January, colder than in 83% of U.S. towns
High summer brings afternoon highs near 82°. Summers stay cool: July afternoons here are cooler than in 77% of U.S. towns. Warming shows here too: 1.7° more than in 1901–2000, led by December. Warm coats and heating bills mark the months from November to April, when means dip under 50°.
A year in Chatham at a glance
Each month’s typical high and low, and what it brings.
What stands out about Chatham’s climate
Compared with towns across the U.S., with Chatham’s place in New York beside it.
What a year in Chatham feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 171 frost-free days a year
In half of years the last 32° night comes by April 27 and the first by October 14. Frost and day counts come from NOAA’s station at Valatie 1 N, NY, 5 miles from the town’s center, 240 ft lower.
The 2023 USDA map puts Chatham’s center in zone 6a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −9°. 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 50 inches of snow a winter
Snow, measured at Copake, NY, falls mostly in January. Precipitation (rain plus melted snow) adds up to 43 inches a year; September is the wettest month and February the driest. Rain or snow falls on about 133 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Chatham
90% 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 Valatie 1 N, NY.
Living with Chatham’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
171 frost-free days in zone 6a. The last frost comes by Apr 27 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 14.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August and September. 7.6 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Chatham from natural hazards, river flooding is the largest share (77%); heat waves, cold waves, winter storms and ice storms together are 4%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Chatham and its neighbors
New Lebanon has the coldest January nights next door (14°, 1° colder) and Kinderhook the hottest July afternoons (84°, 2° warmer). Differences under a degree are within what the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Chatham’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 |
|---|---|---|---|---|
| Chatham, NY | 15° | 82° | 43" | 50" |
| Ontario, OH | 17° | 82° | 42" | 49" |
| Grove City, PA | 18° | 83° | 44" | 54" |
| Mishawaka, IN | 17° | 83° | 40" | 50" |
| Coldwater, MI | 17° | 83° | 39" | 43" |
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 Chatham averaged 1.7° warmer than the 1900s. The biggest change is in December (+3.3°).
A bigger shift than in 69% 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 Chatham compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Chatham’s place among New York’s.
Chatham weather by month
Highs, lows and precipitation from NOAA’s grid at Chatham’s center; snow, wet days and snow on the ground from Copake, NY. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 33° | 15° | 3.0" | 15.5" | 12 | 14° – 31° |
| February | 36° | 17° | 2.3" | 10.0" | 9 | 12° – 33° |
| March | 45° | 25° | 2.9" | 10.0" | 12 | 27° – 46° |
| April | 58° | 35° | 3.3" | 1.8" | 12 | 41° – 52° |
| May | 70° | 46° | 3.7" | 0.0" | 14 | 53° – 64° |
| June | 78° | 55° | 4.3" | 0.0" | 12 | 64° – 71° |
| July | 82° | 60° | 4.2" | 0.0" | 10 | 67° – 75° |
| August | 80° | 58° | 4.4" | 0.0" | 10 | 66° – 73° |
| September | 73° | 51° | 4.4" | 0.0" | 11 | 59° – 66° |
| October | 61° | 40° | 3.9" | 0.0" | 11 | 46° – 57° |
| November | 49° | 31° | 3.1" | 1.8" | 11 | 35° – 45° |
| December | 38° | 22° | 3.5" | 10.5" | 11 | 23° – 41° |
| Year | 58° | 38° | 43.0" | 49.6" | 133 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 12° to 33°. August is the most reliable, staying within 7°.
Where Chatham’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 Chatham’s center.
- Snow: Copake, NY.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Valatie 1 N, NY, 5 miles from the town’s center, 240 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 Chatham’s climate
What is the weather like in Chatham?
A typical July afternoon reaches 82°, a January night drops to 15°, and about 50 inches of snow falls in a normal winter. Colder January nights than 83% of U.S. towns; cooler July afternoons than 77% of U.S. towns.
How cold does it get in Chatham in winter?
January nights average 15°. About 144 nights a year reach 32° or below and 9 reach 0° or below. In the coldest January of the last 30 years the month averaged 14°.
How much snow does Chatham get?
About 50 inches in a normal winter at Copake, NY, most of it in January.
How hot does it get in Chatham?
July, with a typical high of 82° and a low of 60°. About 10 days a year reach 90° (Valatie 1 N, NY).
When is the first and last frost in Chatham?
In half of years the last spring frost (32°) comes by April 27 and the first fall frost by October 14, about 171 frost-free days, at Valatie 1 N, NY.
What growing zone is Chatham in?
Zone 6a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −9°.
What is the best time of year to visit Chatham?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, July, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Chatham getting warmer?
Yes: 1991–2020 averaged 1.7° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 69% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Chatham.
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.