Harrison, IL climate
Harrison has chilly winters and warm summers. A typical July afternoon reaches 89°, a January night drops to 24°, and about 10 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Harrison feels like
Winter
Spring
Summer
Fall
Harrison 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 | 30-yr range |
|---|---|---|---|---|---|---|
| January | 42° | 24° | 3.1" | 3.2" | 7 | 27° – 42° |
| February | 47° | 28° | 2.8" | 1.9" | 8 | 25° – 46° |
| March | 57° | 36° | 4.1" | 0.5" | 10 | 39° – 59° |
| April | 68° | 45° | 5.3" | 0 | 10 | 49° – 62° |
| May | 77° | 55° | 5.2" | 0 | 11 | 61° – 73° |
| June | 85° | 64° | 4.4" | 0 | 9 | 69° – 79° |
| July | 89° | 68° | 3.9" | 0 | 7 | 72° – 84° |
| August | 88° | 65° | 3.3" | 0 | 7 | 71° – 83° |
| September | 81° | 57° | 3.3" | 0 | 6 | 65° – 76° |
| October | 70° | 46° | 3.5" | 0 | 8 | 54° – 63° |
| November | 56° | 35° | 4.2" | 0.3" | 7 | 38° – 51° |
| December | 45° | 28° | 3.3" | 4.0" | 8 | 23° – 46° |
| Year | 67° | 46° | 46.4" | 9.9" | 98 |
“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 Harrison
Harrison gets 46 inches of rain and melted snow a year. April is the wettest month and February the driest. Rain or snow falls on about 98 days a year.
About 195 frost-free days a year
In half of years the last 32° night comes by April 9 and the first one by October 22. That leaves about 195 frost-free days for gardens, longer than 69% of U.S. towns.
Heating and cooling a home in Harrison
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Harrison, 77% of that work is heating and 23% is cooling.
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 Harrison 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 Harrison averaged 1.0° warmer than the 1900s. The biggest change is in February (+2.0°). The shift is smaller than in 73% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Harrison’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 23° to 46°. October is the most reliable, staying within 10°.
Common questions about Harrison’s climate
What is the coldest month in Harrison?
January, with a typical high of 42° and a low of 24°.
What is the hottest month in Harrison?
July, with a typical high of 89° and a low of 68°. About 41 days a year reach 90°.
How much snow does Harrison get?
About 10 inches in a normal winter, most of it in December.
When is the first frost in Harrison?
In half of years the first 32° night comes by October 22, and the last spring frost by April 9.
What is the rainiest month in Harrison?
April, with 5.3 inches of rain and melted snow. The year totals 46 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Harrison itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Murphysboro 2 Sw, IL (3 mi, snow) and Carbondale Southern Il Airport, IL (5 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.