Leaf River, IL climate
Leaf River has cold, snowy winters and pleasant summers. A typical July afternoon reaches 84°, a January night drops to 13°, and about 32 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Leaf River feels like
Winter
Spring
Summer
Fall
Leaf River 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 | 29° | 13° | 1.6" | 13.6" | 7 | 11° – 34° |
| February | 34° | 17° | 1.7" | 6.7" | 6 | 12° – 37° |
| March | 46° | 27° | 2.4" | 3.0" | 7 | 29° – 52° |
| April | 60° | 37° | 3.8" | 0.8" | 8 | 40° – 55° |
| May | 72° | 49° | 4.4" | 0 | 10 | 54° – 66° |
| June | 81° | 58° | 5.2" | 0 | 9 | 66° – 74° |
| July | 84° | 62° | 4.1" | 0 | 7 | 67° – 79° |
| August | 82° | 60° | 4.0" | 0 | 7 | 65° – 77° |
| September | 75° | 52° | 3.7" | 0 | 7 | 58° – 68° |
| October | 63° | 40° | 3.0" | 0 | 7 | 47° – 58° |
| November | 47° | 30° | 2.4" | 1.5" | 6 | 30° – 48° |
| December | 34° | 19° | 2.0" | 6.7" | 7 | 13° – 37° |
| Year | 59° | 39° | 38.3" | 32.3" | 88 |
“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 Leaf River
Leaf River gets 38 inches of rain and melted snow a year. June is the wettest month and January the driest. Rain or snow falls on about 88 days a year.
About 169 frost-free days a year
In half of years the last 32° night comes by April 26 and the first one by October 13. That leaves about 169 frost-free days for gardens, shorter than 62% of U.S. towns.
Heating and cooling a home in Leaf River
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Leaf River, 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.
Leaf River and its neighbors
Leaf River borders 5 towns with climate data. January nights across them vary by 0.5°. Maryland has the coldest January nights (13°) and Rockvale the hottest July afternoons (84°). Leaf River’s January low is 13° and its July high 84°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Leaf River 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 Leaf River averaged 1.3° warmer than the 1900s. The biggest change is in December (+2.5°). The shift is larger than in 55% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Leaf River’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 12° to 37°. June is the most reliable, staying within 8°.
Common questions about Leaf River’s climate
What is the coldest month in Leaf River?
January, with a typical high of 29° and a low of 13°.
What is the hottest month in Leaf River?
July, with a typical high of 84° and a low of 62°. About 11 days a year reach 90°.
How much snow does Leaf River get?
About 32 inches in a normal winter, most of it in January.
When is the first frost in Leaf River?
In half of years the first 32° night comes by October 13, and the last spring frost by April 26.
What is the rainiest month in Leaf River?
June, with 5.2 inches of rain and melted snow. The year totals 38 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Leaf River itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Oregon, IL (11 mi, snow) and Freeport Waste Wtp, IL (14 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.