Cairo, IL climate
Cairo has chilly winters and warm summers, with plenty of rain. A typical July afternoon reaches 89°, a January night drops to 27°, and about 7 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Cairo feels like
Winter
Spring
Summer
Fall
Cairo 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 | 44° | 27° | 3.8" | 2.1" | 10 | 2 | 29° – 44° |
| February | 49° | 30° | 3.8" | 2.5" | 10 | 2 | 28° – 48° |
| March | 59° | 38° | 4.9" | 0.7" | 10 | 0 | 41° – 61° |
| April | 70° | 47° | 5.2" | 0 | 10 | 0 | 52° – 63° |
| May | 78° | 58° | 5.0" | 0 | 10 | 0 | 63° – 75° |
| June | 86° | 66° | 4.2" | 0 | 9 | 0 | 71° – 81° |
| July | 89° | 69° | 4.1" | 0 | 8 | 0 | 75° – 84° |
| August | 89° | 67° | 3.0" | 0 | 6 | 0 | 73° – 83° |
| September | 82° | 59° | 3.3" | 0 | 7 | 0 | 67° – 77° |
| October | 71° | 48° | 4.0" | 0.1" | 8 | 0 | 55° – 64° |
| November | 58° | 38° | 4.3" | 0 | 8 | 0 | 41° – 53° |
| December | 47° | 31° | 4.3" | 1.8" | 10 | 2 | 26° – 48° |
| Year | 69° | 48° | 49.9" | 7.2" | 107 | 7 |
“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 Cairo
Cairo gets 50 inches of rain and melted snow a year. April is the wettest month and August the driest. Rain or snow falls on about 107 days a year. Snow covers the ground about 7 days of the year.
About 211 frost-free days a year
In half of years the last 32° night comes by April 2 and the first one by October 31. That leaves about 211 frost-free days for gardens, longer than 79% of U.S. towns.
Heating and cooling a home in Cairo
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Cairo, 72% of that work is heating and 28% 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 Cairo 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 Cairo averaged 0.9° warmer than the 1900s. The biggest change is in February (+2.1°). The shift is smaller than in 81% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Cairo’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 26° to 48°. October is the most reliable, staying within 9°.
Common questions about Cairo’s climate
What is the coldest month in Cairo?
January, with a typical high of 44° and a low of 27°.
What is the hottest month in Cairo?
July, with a typical high of 89° and a low of 69°. About 42 days a year reach 90°.
How much snow does Cairo get?
About 7 inches in a normal winter, most of it in February.
When is the first frost in Cairo?
In half of years the first 32° night comes by October 31, and the last spring frost by April 2.
What is the rainiest month in Cairo?
April, with 5.2 inches of rain and melted snow. The year totals 50 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Cairo itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Grand Chain Dam 53, IL (16 mi, snow) and Cairo 3n, IL (2 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.