Mount Joy, PA climate
Mount Joy has chilly winters and warm summers. A typical July afternoon reaches 87°, a January night drops to 22°, and about 28 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Mount Joy feels like
Winter
Spring
Summer
Fall
Mount Joy 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 | 40° | 22° | 3.3" | 8.7" | 9 | 6 | 22° – 39° |
| February | 43° | 24° | 2.6" | 8.8" | 8 | 8 | 22° – 41° |
| March | 52° | 31° | 3.8" | 4.4" | 10 | 3 | 35° – 51° |
| April | 64° | 41° | 3.7" | 0.2" | 11 | 0 | 48° – 58° |
| May | 74° | 50° | 4.1" | 0 | 13 | 0 | 57° – 68° |
| June | 82° | 60° | 4.2" | 0 | 11 | 0 | 67° – 74° |
| July | 87° | 64° | 4.3" | 0 | 11 | 0 | 70° – 79° |
| August | 85° | 62° | 3.5" | 0 | 10 | 0 | 69° – 77° |
| September | 78° | 55° | 4.8" | 0 | 9 | 0 | 64° – 70° |
| October | 66° | 44° | 3.9" | 0.1" | 9 | 0 | 51° – 61° |
| November | 54° | 34° | 3.3" | 0.8" | 8 | 0 | 38° – 49° |
| December | 44° | 27° | 3.6" | 4.5" | 9 | 3 | 26° – 46° |
| Year | 64° | 43° | 45.0" | 27.5" | 117 | 21 |
“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 Mount Joy
Mount Joy gets 45 inches of rain and melted snow a year. September is the wettest month and February the driest. Rain or snow falls on about 117 days a year. Snow covers the ground about 21 days of the year.
About 180 frost-free days a year
In half of years the last 32° night comes by April 24 and the first one by October 21. That leaves about 180 frost-free days for gardens, longer than 53% of U.S. towns.
Heating and cooling a home in Mount Joy
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Mount Joy, 86% of that work is heating and 14% 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.
Mount Joy and its neighbors
Mount Joy borders 4 towns with climate data. January nights across them vary by 0.4°. Mount Pleasant has the coldest January nights (22°) and Cumberland the hottest July afternoons (87°). Mount Joy’s January low is 22° and its July high 87°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Mount Joy 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 Mount Joy averaged 1.5° warmer than the 1900s. The biggest change is in December (+2.9°). The shift is larger than in 70% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Mount Joy’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. December swings the most: between 1991 and 2020 its average temperature ranged from 26° to 46°. September is the most reliable, staying within 7°.
Common questions about Mount Joy’s climate
What is the coldest month in Mount Joy?
January, with a typical high of 40° and a low of 22°.
What is the hottest month in Mount Joy?
July, with a typical high of 87° and a low of 64°. About 21 days a year reach 90°.
How much snow does Mount Joy get?
About 28 inches in a normal winter, most of it in February.
When is the first frost in Mount Joy?
In half of years the first 32° night comes by October 21, and the last spring frost by April 24.
What is the rainiest month in Mount Joy?
September, with 4.8 inches of rain and melted snow. The year totals 45 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Mount Joy itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Emmitsburg 2 Se, MD (8 mi, snow) and Eisenhower Nhs, PA (4 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.