Photo: Michael Barera · CC BY-SA 4.0Winter nights in West Allis are colder than in 87% of U.S. towns
Midsummer highs settle at about 82°. The seasons are far apart: from a winter night to a summer afternoon the average spans 68°. Its July afternoons stay fresher than in 83% of U.S. towns. Radiators earn their keep from November to April, the months that average under 50°.
A year in West Allis at a glance
Each month’s typical high and low, and what it brings.
What stands out about West Allis’ climate
Compared with towns across the U.S., with West Allis’ place in Wisconsin beside it.
What a year in West Allis feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 173 frost-free days a year
In half of years the last 32° night comes by April 26 and the first by October 18. Frost and day counts come from NOAA’s station at Mt Mary College, WI, 4 miles from the city’s center point, at about the same height.
The 2023 USDA map puts West Allis’ center in zone 5b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −11°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 40 inches of snow a winter
Snow, measured at Mt Mary College, WI, is heaviest from January through February, about 10 inches a month. Precipitation (rain plus melted snow) adds up to 35 inches a year; June is the wettest month and February the driest. Rain or snow falls on about 120 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in West Allis
90% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Mt Mary College, WI.
Living with West Allis’ climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
173 frost-free days in zone 5b. The last frost comes by Apr 26 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 18.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August and September. 4.9 miles of trails are waiting.
Parks & trails →Cold waves are 55% of the yearly building losses FEMA expects in West Allis from natural hazards, the largest share. Normals are averages; the hazards page covers the extremes.
Natural hazards →West Allis and its neighbors
New Berlin has the coldest January nights next door (13°, 1° colder). Differences under a degree are within what the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like West Allis’, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| West Allis, WI | 14° | 82° | 35" | 40" |
| Horseheads, NY | 16° | 82° | 36" | 42" |
| Milford, MI | 15° | 82° | 33" | 36" |
| Kendallville, IN | 17° | 83° | 38" | 36" |
| Sayre, PA | 17° | 84° | 37" | 35" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
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°).
A smaller shift than in 53% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How West Allis compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with West Allis’ place among Wisconsin’s.
West Allis weather by month
Highs, lows and precipitation from NOAA’s grid at West Allis’ center; snow, wet days and snow on the ground from Mt Mary College, WI. 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" | 0.0" | 13 | 0 | 51° – 62° |
| June | 77° | 56° | 4.5" | 0.0" | 11 | 0 | 63° – 72° |
| July | 82° | 61° | 3.5" | 0.0" | 10 | 0 | 66° – 78° |
| August | 80° | 60° | 3.8" | 0.0" | 10 | 0 | 65° – 75° |
| September | 73° | 53° | 3.3" | 0.0" | 9 | 0 | 57° – 67° |
| October | 60° | 41° | 2.9" | 0.0" | 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 |
How much a month can swing
A normal is an average. March swings the most: from 1991 to 2020 its average ranged from 27° to 49°. June is the most reliable, staying within 9°.
Where West Allis’ numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at West Allis’ center.
- Snow: Mt Mary College, WI.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Mt Mary College, WI, 4 miles from the city’s center point, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about West Allis’ climate
What is the weather like in West Allis?
A typical July afternoon reaches 82°, a January night drops to 14°, and about 40 inches of snow falls in a normal winter. Colder January nights than 87% of U.S. towns; cooler July afternoons than 83% of U.S. towns.
How cold does it get in West Allis in winter?
January nights average 14°. About 134 nights a year reach 32° or below and 11 reach 0° or below. In the coldest January of the last 30 years the month averaged 11°.
How much snow does West Allis get?
About 40 inches in a normal winter at Mt Mary College, WI, heaviest from January through February, about 10 inches a month, with snow on the ground about 58 days a year.
How hot does it get in West Allis?
July, with a typical high of 82° and a low of 61°. About 17 days a year reach 90° (Mt Mary College, WI).
When is the first and last frost in West Allis?
In half of years the last spring frost (32°) comes by April 26 and the first fall frost by October 18, about 173 frost-free days, at Mt Mary College, WI.
What growing zone is West Allis in?
Zone 5b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −11°.
What is the best time of year to visit West Allis?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, July, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is West Allis getting warmer?
Yes: 1991–2020 averaged 1.3° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 53% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in West Allis.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.