West Allis, WI climate
West Allis has cold, snowy winters and pleasant summers. A typical July afternoon reaches 82°, a January night drops to 14°, and about 40 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in West Allis feels like
Winter
Spring
Summer
Fall
West Allis 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 | 29° | 14° | 1.6" | 11.0" | 10 | 20 | 11° – 33° |
| February | 33° | 17° | 1.6" | 9.9" | 9 | 17 | 13° – 35° |
| March | 44° | 26° | 2.1" | 5.3" | 9 | 7 | 27° – 49° |
| April | 55° | 35° | 3.8" | 1.5" | 12 | 1 | 37° – 51° |
| May | 67° | 46° | 3.8" | 0 | 13 | 0 | 51° – 62° |
| June | 77° | 56° | 4.5" | 0 | 11 | 0 | 63° – 72° |
| July | 82° | 61° | 3.5" | 0 | 10 | 0 | 66° – 78° |
| August | 80° | 60° | 3.8" | 0 | 10 | 0 | 65° – 75° |
| September | 73° | 53° | 3.3" | 0 | 9 | 0 | 57° – 67° |
| October | 60° | 41° | 2.9" | 0 | 11 | 0 | 46° – 57° |
| November | 46° | 30° | 2.2" | 2.0" | 9 | 2 | 29° – 47° |
| December | 35° | 20° | 1.9" | 9.8" | 10 | 12 | 16° – 37° |
| Year | 57° | 38° | 34.9" | 39.5" | 120 | 58 |
“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 West Allis
West Allis gets 35 inches of rain and melted snow a year. June is the wettest month and February the driest. Rain or snow falls on about 120 days a year. Snow covers the ground about 58 days of the year.
About 173 frost-free days a year
In half of years the last 32° night comes by April 26 and the first one by October 18. That leaves about 173 frost-free days for gardens, shorter than 57% of U.S. towns.
Heating and cooling a home in West Allis
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In West Allis, 90% of that work is heating and 10% 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.
West Allis and its neighbors
West Allis borders 5 towns with climate data. January nights across them vary by 1.8°. New Berlin has the coldest January nights (13°) and Greenfield the hottest July afternoons (82°). West Allis’s January low is 14° and its July high 82°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How West Allis 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 West Allis averaged 1.3° warmer than the 1900s. The biggest change is in December (+3.1°). The shift is larger than in 58% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at West Allis’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. March swings the most: between 1991 and 2020 its average temperature ranged from 27° to 49°. June is the most reliable, staying within 9°.
Common questions about West Allis’s climate
What is the coldest month in West Allis?
January, with a typical high of 29° and a low of 14°.
What is the hottest month in West Allis?
July, with a typical high of 82° and a low of 61°. About 17 days a year reach 90°.
How much snow does West Allis get?
About 40 inches in a normal winter, most of it in January.
When is the first frost in West Allis?
In half of years the first 32° night comes by October 18, and the last spring frost by April 26.
What is the rainiest month in West Allis?
June, with 4.5 inches of rain and melted snow. The year totals 35 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for West Allis itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Mt Mary College, WI (4 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.