Alto Pass, IL climate
Alto Pass has chilly winters and warm summers, with plenty of rain. A typical July afternoon reaches 88°, a January night drops to 25°, and about 6 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Alto Pass feels like
Winter
Spring
Summer
Fall
Alto Pass 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 | 42° | 25° | 3.4" | 1.7" | 7 | 27° – 42° |
| February | 47° | 28° | 3.2" | 1.7" | 6 | 26° – 46° |
| March | 57° | 36° | 4.4" | 1.0" | 9 | 40° – 59° |
| April | 68° | 45° | 5.4" | 0 | 8 | 49° – 62° |
| May | 77° | 55° | 5.2" | 0 | 8 | 61° – 73° |
| June | 85° | 64° | 4.5" | 0 | 7 | 69° – 79° |
| July | 88° | 68° | 4.1" | 0 | 6 | 72° – 84° |
| August | 87° | 65° | 3.3" | 0 | 5 | 71° – 83° |
| September | 81° | 58° | 3.3" | 0 | 6 | 65° – 76° |
| October | 69° | 46° | 3.7" | 0.1" | 6 | 54° – 63° |
| November | 55° | 36° | 4.4" | 0.1" | 7 | 38° – 51° |
| December | 45° | 28° | 3.6" | 1.6" | 7 | 24° – 46° |
| Year | 67° | 46° | 48.4" | 6.2" | 82 |
“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 Alto Pass
Alto Pass 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 82 days a year.
About 203 frost-free days a year
In half of years the last 32° night comes by April 8 and the first one by October 29. That leaves about 203 frost-free days for gardens, longer than 74% of U.S. towns.
Heating and cooling a home in Alto Pass
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Alto Pass, 71% of that work is heating and 29% 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 Alto Pass 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 Alto Pass averaged 1.0° warmer than the 1900s. The biggest change is in February (+1.9°). The shift is smaller than in 70% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Alto Pass’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 24° to 46°. October is the most reliable, staying within 9°.
Common questions about Alto Pass’s climate
What is the coldest month in Alto Pass?
January, with a typical high of 42° and a low of 25°.
What is the hottest month in Alto Pass?
July, with a typical high of 88° and a low of 68°. About 43 days a year reach 90°.
How much snow does Alto Pass get?
About 6 inches in a normal winter, most of it in January.
When is the first frost in Alto Pass?
In half of years the first 32° night comes by October 29, and the last spring frost by April 8.
What is the rainiest month in Alto Pass?
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 Alto Pass itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Grand Twr 2 N, IL (12 mi, snow) and Anna 2 Nne, IL (8 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.