Carol Stream, IL climate
Carol Stream has chilly, snowy winters and pleasant summers. A typical July afternoon reaches 84°, a January night drops to 15°, and about 46 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Carol Stream feels like
Winter
Spring
Summer
Fall
Carol Stream 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 | 30° | 15° | 1.8" | 11.2" | 11 | 14° – 34° |
| February | 35° | 19° | 1.8" | 13.0" | 10 | 14° – 38° |
| March | 46° | 28° | 2.3" | 5.0" | 11 | 29° – 52° |
| April | 59° | 37° | 3.8" | 2.9" | 12 | 40° – 55° |
| May | 71° | 48° | 4.8" | 0 | 13 | 53° – 66° |
| June | 80° | 58° | 4.5" | 0 | 12 | 65° – 74° |
| July | 84° | 63° | 3.8" | 0 | 10 | 68° – 80° |
| August | 82° | 62° | 3.9" | 0 | 9 | 66° – 78° |
| September | 75° | 54° | 3.4" | 0 | 9 | 59° – 69° |
| October | 62° | 42° | 3.4" | 0.2" | 11 | 48° – 58° |
| November | 48° | 31° | 2.5" | 3.7" | 9 | 32° – 48° |
| December | 36° | 21° | 2.1" | 10.2" | 12 | 15° – 38° |
| Year | 59° | 40° | 38.2" | 46.2" | 129 |
“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 Carol Stream
Carol Stream gets 38 inches of rain and melted snow a year. May is the wettest month and February the driest. Rain or snow falls on about 129 days a year.
About 174 frost-free days a year
In half of years the last 32° night comes by April 25 and the first one by October 19. That leaves about 174 frost-free days for gardens, shorter than 56% of U.S. towns.
Heating and cooling a home in Carol Stream
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Carol Stream, 89% of that work is heating and 11% 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.
Carol Stream and its neighbors
Carol Stream borders 9 towns with climate data. January nights across them vary by 0.7°. Bartlett has the coldest January nights (15°) and Winfield the hottest July afternoons (84°). Carol Stream’s January low is 15° and its July high 84°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Carol Stream 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 Carol Stream averaged 1.3° warmer than the 1900s. The biggest change is in December (+2.6°). The shift is larger than in 58% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Carol Stream’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 14° to 38°. June is the most reliable, staying within 9°.
Common questions about Carol Stream’s climate
What is the coldest month in Carol Stream?
January, with a typical high of 30° and a low of 15°.
What is the hottest month in Carol Stream?
July, with a typical high of 84° and a low of 63°. About 15 days a year reach 90°.
How much snow does Carol Stream get?
About 46 inches in a normal winter, most of it in February.
When is the first frost in Carol Stream?
In half of years the first 32° night comes by October 19, and the last spring frost by April 25.
What is the rainiest month in Carol Stream?
May, with 4.8 inches of rain and melted snow. The year totals 38 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Carol Stream itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at St. Charles 0.1 E, IL (9 mi, snow) and West Chicago Dupage Airport, IL (6 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.