Rocky Run-Wilcox, IL climate
Rocky Run-Wilcox has chilly winters and warm summers. A typical July afternoon reaches 87°, a January night drops to 18°, and about 23 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeRight about normal today. The forecast high is 72°, and a typical Oct 1 in Rocky Run-Wilcox peaks around 72°.Live forecast: National Weather Service · Normal: NOAA 1991–2020
What a year in Rocky Run-Wilcox feels like
Winter
Spring
Summer
Fall
Rocky Run-Wilcox 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 | 35° | 18° | 1.7" | 7.6" | 8 | 15 | 19° – 38° |
| February | 40° | 22° | 1.9" | 6.3" | 7 | 8 | 18° – 42° |
| March | 52° | 32° | 2.5" | 2.1" | 9 | 2 | 34° – 56° |
| April | 64° | 42° | 4.1" | 0.4" | 11 | 0 | 45° – 60° |
| May | 74° | 53° | 5.1" | 0 | 12 | 0 | 58° – 72° |
| June | 83° | 63° | 4.9" | 0 | 10 | 0 | 69° – 77° |
| July | 87° | 67° | 4.2" | 0 | 9 | 0 | 71° – 83° |
| August | 85° | 65° | 3.9" | 0 | 8 | 0 | 69° – 80° |
| September | 79° | 56° | 3.5" | 0 | 7 | 0 | 62° – 72° |
| October | 66° | 45° | 3.3" | 0.1" | 8 | 0 | 50° – 61° |
| November | 52° | 33° | 2.6" | 1.4" | 8 | 1 | 35° – 52° |
| December | 40° | 23° | 2.0" | 5.2" | 8 | 6 | 17° – 41° |
| Year | 63° | 43° | 39.4" | 23.1" | 106 | 32 |
“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 Rocky Run-Wilcox
Rocky Run-Wilcox gets 39 inches of rain and melted snow a year. May is the wettest month and January the driest. Rain or snow falls on about 106 days a year. Snow covers the ground about 32 days of the year.
About 198 frost-free days a year
In half of years the last 32° night comes by April 10 and the first one by October 27. That leaves about 198 frost-free days for gardens, longer than 71% of U.S. towns.
Heating and cooling a home in Rocky Run-Wilcox
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Rocky Run-Wilcox, 84% of that work is heating and 16% 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.
Rocky Run-Wilcox and its neighbors
Rocky Run-Wilcox borders 7 towns with climate data. January nights across them vary by 0.9°. Montebello has the coldest January nights (17°) and Warsaw the hottest July afternoons (87°). Rocky Run-Wilcox’s January low is 18° and its July high 87°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Rocky Run-Wilcox 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 Rocky Run-Wilcox averaged 0.6° warmer than the 1900s. The biggest change is in December (+1.8°). The shift is smaller than in 94% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Rocky Run-Wilcox’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 18° to 42°. June is the most reliable, staying within 7°.
Common questions about Rocky Run-Wilcox’s climate
What is the coldest month in Rocky Run-Wilcox?
January, with a typical high of 35° and a low of 18°.
What is the hottest month in Rocky Run-Wilcox?
July, with a typical high of 87° and a low of 67°. About 26 days a year reach 90°.
How much snow does Rocky Run-Wilcox get?
About 23 inches in a normal winter, most of it in January.
When is the first frost in Rocky Run-Wilcox?
In half of years the first 32° night comes by October 27, and the last spring frost by April 10.
What is the rainiest month in Rocky Run-Wilcox?
May, with 5.1 inches of rain and melted snow. The year totals 39 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Rocky Run-Wilcox itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Bentley, IL (18 mi, snow) and Keokuk Lock Dam 19, IA (9 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.