Chatham, PA climate
Chatham has cold, snowy winters and pleasant summers. A typical July afternoon reaches 80°, a January night drops to 15°, and about 49 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Chatham feels like
Winter
Spring
Summer
Fall
Chatham weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 31° | 15° | 2.6" | 10.6" | 13 | 21 | 13° – 31° |
| February | 34° | 15° | 2.0" | 10.5" | 10 | 17 | 11° – 33° |
| March | 43° | 23° | 2.9" | 10.6" | 10 | 16 | 26° – 45° |
| April | 56° | 32° | 3.3" | 2.4" | 10 | 2 | 38° – 50° |
| May | 68° | 43° | 3.6" | 0 | 11 | 0 | 49° – 61° |
| June | 76° | 52° | 4.0" | 0 | 11 | 0 | 60° – 67° |
| July | 80° | 56° | 4.0" | 0 | 10 | 0 | 63° – 71° |
| August | 78° | 54° | 3.6" | 0 | 10 | 0 | 63° – 70° |
| September | 71° | 48° | 4.2" | 0 | 9 | 0 | 55° – 63° |
| October | 59° | 37° | 3.7" | 0.6" | 10 | 0 | 43° – 55° |
| November | 46° | 29° | 2.9" | 3.3" | 10 | 4 | 32° – 43° |
| December | 36° | 21° | 2.9" | 10.7" | 12 | 15 | 19° – 39° |
| Year | 56° | 35° | 39.9" | 48.7" | 126 | 75 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Chatham
Chatham gets 40 inches of rain and melted snow a year. September is the wettest month and February the driest. Rain or snow falls on about 126 days a year. Snow covers the ground about 75 days of the year.
About 148 frost-free days a year
In half of years the last 32° night comes by May 10 and the first one by October 5. That leaves about 148 frost-free days for gardens, shorter than 82% of U.S. towns.
Heating and cooling a home in Chatham
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Chatham, 96% of that work is heating and 4% is cooling, so the furnace matters far more than the air conditioner.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
Chatham and its neighbors
Chatham borders 5 towns with climate data. January nights across them vary by 0.7°. Clymer has the coldest January nights (15°) and Middlebury the hottest July afternoons (81°). Chatham’s January low is 15° and its July high 80°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Chatham compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Chatham averaged 0.9° warmer than the 1900s. The biggest change is in December (+2.6°). The shift is smaller than in 75% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Chatham’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. February swings the most: between 1991 and 2020 its average temperature ranged from 11° to 33°. June is the most reliable, staying within 7°.
Common questions about Chatham’s climate
What is the coldest month in Chatham?
January, with a typical high of 31° and a low of 15°.
What is the hottest month in Chatham?
July, with a typical high of 80° and a low of 56°. About 2 days a year reach 90°.
How much snow does Chatham get?
About 49 inches in a normal winter, most of it in December.
When is the first frost in Chatham?
In half of years the first 32° night comes by October 5, and the last spring frost by May 10.
What is the rainiest month in Chatham?
September, with 4.2 inches of rain and melted snow. The year totals 40 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Chatham itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Sabinsville 3 Se, PA (3 mi, snow) and Wellsboro 4 Sw, PA (12 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.