Marion, IL climate
Marion has chilly winters and warm summers, with plenty of rain. A typical July afternoon reaches 88°, a January night drops to 25°, and about 10 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Marion feels like
Winter
Spring
Summer
Fall
Marion 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 | 41° | 25° | 3.3" | 2.3" | 8 | 27° – 42° |
| February | 46° | 28° | 3.2" | 2.9" | 7 | 25° – 46° |
| March | 56° | 36° | 4.5" | 1.4" | 9 | 39° – 60° |
| April | 68° | 45° | 5.5" | 0.1" | 9 | 50° – 62° |
| May | 77° | 55° | 5.1" | 0 | 10 | 61° – 72° |
| June | 85° | 64° | 4.5" | 0 | 8 | 69° – 79° |
| July | 88° | 67° | 4.0" | 0 | 8 | 72° – 84° |
| August | 87° | 65° | 3.3" | 0 | 7 | 71° – 82° |
| September | 81° | 57° | 3.4" | 0 | 6 | 65° – 75° |
| October | 70° | 46° | 3.7" | 0.3" | 6 | 54° – 63° |
| November | 56° | 36° | 4.2" | 0.1" | 7 | 39° – 52° |
| December | 45° | 28° | 3.6" | 2.7" | 8 | 23° – 46° |
| Year | 67° | 46° | 48.2" | 9.8" | 94 |
“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 Marion
Marion gets 48 inches of rain and melted snow a year. April is the wettest month and February the driest. Rain or snow falls on about 94 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 Marion
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Marion, 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 Marion 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 Marion averaged 0.9° warmer than the 1900s. The biggest change is in February (+1.9°). The shift is smaller than in 76% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Marion’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 9°.
Common questions about Marion’s climate
What is the coldest month in Marion?
January, with a typical high of 41° and a low of 25°.
What is the hottest month in Marion?
July, with a typical high of 88° and a low of 67°. About 38 days a year reach 90°.
How much snow does Marion get?
About 10 inches in a normal winter, most of it in February.
When is the first frost in Marion?
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 Marion?
April, with 5.5 inches of rain and melted snow. The year totals 48 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Marion itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Plumfield, IL (12 mi, snow) and Carbondale Sewage Plt, IL (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.