Flannigan, IL climate
Flannigan has chilly winters and warm summers, with plenty of rain. A typical July afternoon reaches 88°, a January night drops to 24°, and about 13 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Flannigan feels like
Winter
Spring
Summer
Fall
Flannigan 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 | 41° | 24° | 3.4" | 3.7" | 11 | 6 | 27° – 42° |
| February | 46° | 28° | 3.1" | 3.3" | 9 | 3 | 26° – 46° |
| March | 56° | 36° | 4.4" | 2.1" | 12 | 1 | 38° – 59° |
| April | 68° | 45° | 5.4" | 0 | 13 | 0 | 50° – 62° |
| May | 76° | 55° | 5.2" | 0 | 13 | 0 | 61° – 73° |
| June | 85° | 64° | 4.7" | 0 | 11 | 0 | 69° – 78° |
| July | 88° | 67° | 4.0" | 0 | 8 | 0 | 72° – 84° |
| August | 87° | 65° | 3.3" | 0 | 8 | 0 | 71° – 81° |
| September | 81° | 57° | 3.4" | 0 | 8 | 0 | 64° – 75° |
| October | 69° | 46° | 3.6" | 0.6" | 8 | 0 | 53° – 63° |
| November | 55° | 36° | 4.1" | 0.2" | 10 | 0 | 38° – 52° |
| December | 45° | 28° | 3.5" | 3.4" | 12 | 4 | 23° – 46° |
| Year | 66° | 46° | 48.0" | 13.3" | 121 | 14 |
“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 Flannigan
Flannigan 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 121 days a year. Snow covers the ground about 14 days of the year.
About 190 frost-free days a year
In half of years the last 32° night comes by April 11 and the first one by October 21. That leaves about 190 frost-free days for gardens, longer than 64% of U.S. towns.
Heating and cooling a home in Flannigan
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Flannigan, 78% of that work is heating and 22% 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.
Flannigan and its neighbors
Flannigan borders 4 towns with climate data. January nights across them vary by 0.4°. Knight Prairie has the coldest January nights (24°) and Twigg the hottest July afternoons (88°). Flannigan’s January low is 24° and its July high 88°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Flannigan 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 Flannigan averaged 0.9° warmer than the 1900s. The biggest change is in February (+2.1°). The shift is smaller than in 80% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Flannigan’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°. June is the most reliable, staying within 10°.
Common questions about Flannigan’s climate
What is the coldest month in Flannigan?
January, with a typical high of 41° and a low of 24°.
What is the hottest month in Flannigan?
July, with a typical high of 88° and a low of 67°. About 43 days a year reach 90°.
How much snow does Flannigan get?
About 13 inches in a normal winter, most of it in January.
When is the first frost in Flannigan?
In half of years the first 32° night comes by October 21, and the last spring frost by April 11.
What is the rainiest month in Flannigan?
April, with 5.4 inches of rain and melted snow. The year totals 48 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Flannigan itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Mcleansboro, IL (9 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.