Derry, PA climate
Derry has chilly, snowy winters and pleasant summers, with plenty of rain. A typical July afternoon reaches 83°, a January night drops to 21°, and about 48 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Derry feels like
Winter
Spring
Summer
Fall
Derry 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 | 37° | 21° | 3.5" | 14.6" | 15 | 14 | 21° – 38° |
| February | 41° | 22° | 3.1" | 10.7" | 12 | 12 | 18° – 40° |
| March | 50° | 29° | 3.8" | 9.6" | 13 | 6 | 33° – 50° |
| April | 63° | 38° | 4.1" | 0.8" | 13 | 1 | 46° – 56° |
| May | 72° | 48° | 4.4" | 0 | 13 | 0 | 54° – 67° |
| June | 80° | 57° | 4.8" | 0 | 11 | 0 | 64° – 70° |
| July | 83° | 61° | 4.6" | 0 | 11 | 0 | 68° – 77° |
| August | 82° | 59° | 4.3" | 0 | 9 | 0 | 67° – 75° |
| September | 76° | 53° | 4.2" | 0 | 9 | 0 | 61° – 69° |
| October | 64° | 42° | 3.5" | 0.3" | 9 | 0 | 49° – 59° |
| November | 52° | 33° | 3.6" | 2.2" | 12 | 2 | 36° – 48° |
| December | 42° | 26° | 3.8" | 10.0" | 13 | 10 | 24° – 45° |
| Year | 62° | 41° | 47.6" | 48.2" | 140 | 44 |
“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 Derry
Derry gets 48 inches of rain and melted snow a year. June is the wettest month and February the driest. Rain or snow falls on about 140 days a year. Snow covers the ground about 44 days of the year.
About 163 frost-free days a year
In half of years the last 32° night comes by May 2 and the first one by October 14. That leaves about 163 frost-free days for gardens, shorter than 68% of U.S. towns.
Heating and cooling a home in Derry
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Derry, 91% of that work is heating and 9% 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.
How Derry 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 Derry averaged 0.8° warmer than the 1900s. The biggest change is in December (+2.1°). The shift is smaller than in 84% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Derry’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 18° to 40°. June is the most reliable, staying within 6°.
Common questions about Derry’s climate
What is the coldest month in Derry?
January, with a typical high of 37° and a low of 21°.
What is the hottest month in Derry?
July, with a typical high of 83° and a low of 61°. About 14 days a year reach 90°.
How much snow does Derry get?
About 48 inches in a normal winter, most of it in January.
When is the first frost in Derry?
In half of years the first 32° night comes by October 14, and the last spring frost by May 2.
What is the rainiest month in Derry?
June, with 4.8 inches of rain and melted snow. The year totals 48 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Derry itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Derry 4 Sw, PA (3 mi, snow) and Loyalhanna Lake, 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.