West Allis, Wisconsin climate: Normal weather by month, frost dates and records
West Allis's normal year runs from 15°F January nights to 85°F July afternoons, with 39.4 inches of precipitation and 52 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 9.5°C, January lows of −10°C, July highs of 29°C, 1,000 mm of precipitation a year.
- NOAA stationWest Allis
- Station IDUSC00479046
- Location43.02°N 88.00°W
- Elevation723 ft (220 m)
- From the center2 miles
- Population59,784
On October 22, the normal high in West Allis is 59°F and the normal low 40°F, and the chance of measurable rain or snow is 38%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for West Allis.
- Jan 31° 15°
- Feb 34° 17°
- Mar 45° 27°
- Apr 57° 37°
- May 70° 48°
- Jun 80° 58°
- Jul 85° 63°
- Aug 83° 62°
- Sep 77° 54°
- Oct 62° 42°
- Nov 48° 30°
- Dec 36° 21°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in West Allis each month?
July is the warmest month, with normal highs of 85°F; January the coldest, with normal lows of 15°F. The most precipitation falls in June (5.03 in), the least in February (2.15 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 31°F | 15°F | 22.8°F | 2.23 | 13.5 | 10 | <1 | 29 | 9 h 20 min |
| February | 34°F | 17°F | 25.5°F | 2.15 | 13.6 | 11 | <1 | 26 | 10 h 30 min |
| March | 45°F | 27°F | 35.9°F | 2.53 | 8.3 | 11 | <1 | 23 | 11 h 50 min |
| April | 57°F | 37°F | 46.6°F | 3.70 | 2.1 | 11 | <1 | 7 | 13 h 20 min |
| May | 70°F | 48°F | 58.7°F | 4.32 | 0.0 | 14 | 1 | 1 | 14 h 40 min |
| June | 80°F | 58°F | 69.0°F | 5.03 | 0.0 | 13 | 4 | <1 | 15 h 20 min |
| July | 85°F | 63°F | 73.9°F | 3.73 | 0.0 | 10 | 7 | <1 | 15 h |
| August | 83°F | 62°F | 72.4°F | 4.34 | 0.0 | 10 | 5 | <1 | 14 h |
| September | 77°F | 54°F | 65.4°F | 3.69 | 0.0 | 9 | 2 | <1 | 12 h 30 min |
| October | 62°F | 42°F | 52.0°F | 3.08 | 0.1 | 12 | <1 | 4 | 11 h 10 min |
| November | 48°F | 30°F | 38.9°F | 2.31 | 1.4 | 11 | <1 | 16 | 9 h 50 min |
| December | 36°F | 21°F | 28.4°F | 2.25 | 13.3 | 12 | <1 | 28 | 9 h |
| Year (annual) | 59°F | 39°F | 49.1°F | 39.36 | 52.3 | 134 | 18 | 133 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −1°C | −10°C | −5.1°C | 57 mm | 34 cm |
| February | 1°C | −8°C | −3.6°C | 55 mm | 35 cm |
| March | 7°C | −3°C | 2.2°C | 64 mm | 21 cm |
| April | 14°C | 3°C | 8.1°C | 94 mm | 5 cm |
| May | 21°C | 9°C | 14.8°C | 110 mm | 0 cm |
| June | 27°C | 15°C | 20.6°C | 128 mm | 0 cm |
| July | 29°C | 17°C | 23.3°C | 95 mm | 0 cm |
| August | 28°C | 17°C | 22.4°C | 110 mm | 0 cm |
| September | 25°C | 12°C | 18.6°C | 94 mm | 0 cm |
| October | 17°C | 6°C | 11.1°C | 78 mm | 0 cm |
| November | 9°C | −1°C | 3.8°C | 59 mm | 4 cm |
| December | 2°C | −6°C | −2.0°C | 57 mm | 34 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00479046; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit West Allis?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. Of those, September has the fewest days with rain (9).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00479046.
When is the last frost in West Allis?
In West Allis, the last spring frost (32°F) comes after April 26 in half of years and after May 12 in one year in ten; the first autumn frost comes before October 22 in half of years and before October 7 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- April 261 year in 10 after May 12; 9 in 10 after April 12
- First autumn frost, half of years before
- October 221 year in 10 before October 7; 9 in 10 before November 3
NOAA puts the median frost-free season at 177 days, and the season without a hard freeze (28°F) at 200 days.
A hard freeze (28°F) comes after April 14 in half of springs and before November 1 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts West Allis in zone 5b across its 3 ZIP code areas (5b in 53214, the largest).
Frost dates for every NOAA station in Wisconsin · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00479046; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
What hardiness zone is each West Allis ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. West Allis's 3 ZIP code areas are all in zone 5b. Each ZIP's frost dates are in the frost tool.
Source: USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; ZIP areas in the place: Census Bureau 2020 ZCTA-to-place relationship file. A ZIP area counts when at least a tenth of its land (and 0.5 km²) lies in the place.
How hot and how cold does it get in West Allis?
In a normal year in West Allis, 18 days a year reach 90°F, 133 nights fall to 32°F or colder and 134 days bring measurable precipitation.
- Days at 90°F or more
- 18a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 133a normal year
- Days that stay below freezing
- 45high of 32°F or less
- Days with 0.01 inch of precipitation
- 134a normal year
- Days with 1 inch of snow or more
- 13a normal year
The highest temperature in this station's record (since 1948) is 104°F, on July 15, 2026; the lowest is −26°F, on January 20, 1985.
The wettest calendar year on that record is 2008, with 49.29 in; the snowiest season is 2007–08, with 122.1 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00479046; records: ACIS (NOAA Regional Climate Centers), station USC00479046. Records use complete months only; a month missing more than three days is left out.
How sunny is West Allis?
Over a year 72% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around West Allis, 3.8 kWh per square metre a day. July is the sunniest month (80%) and December the cloudiest (59%). Among the 459 U.S. places of 50,000 or more, that ranks tied 385th (with 30 others) in sunshine.
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 63% | 1.6 |
| February | 70% | 2.7 |
| March | 70% | 3.7 |
| April | 68% | 4.6 |
| May | 71% | 5.5 |
| June | 76% | 6.1 |
| July | 80% | 6.3 |
| August | 78% | 5.3 |
| September | 77% | 4.2 |
| October | 68% | 2.7 |
| November | 66% | 1.8 |
| December | 59% | 1.3 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does West Allis need?
A normal year in West Allis brings 6,585 heating degree days, 23% more than the median U.S. place (5,373), and 835 cooling degree days, 8% fewer than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,001 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,309 | 0 |
| February | 1,106 | 0 |
| March | 904 | 0 |
| April | 554 | 4 |
| May | 232 | 37 |
| June | 46 | 166 |
| July | 4 | 280 |
| August | 7 | 238 |
| September | 88 | 100 |
| October | 416 | 11 |
| November | 784 | 0 |
| December | 1,134 | 0 |
| Year (annual) | 6,585 | 835 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00479046. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has West Allis been warmer than normal lately?
2025 averaged 48.9°F, 0.2°F below the 1991-2020 normal of 49.1°F. 1 of the 2 complete years since 2024 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2024 | 52.3°F | +3.2°F | 46.29 | 44.1 |
| 2025 | 48.9°F | −0.2°F | 41.78 | 39.9 |
Over 44 complete years from 1952 to 2025, the station's annual mean temperature rose at a fitted 3.1°F per century (+0.17°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00479046; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does West Allis's climate compare?
West Allis is warmer than 161 of the other 164 places with their own NOAA record in Wisconsin, and wetter than 152. Across the 7,247 U.S. stations with normals, its annual mean of 49.1°F is warmer than 36%.
In the Köppen classification computed from these normals, West Allis is Dfa: continental, no dry season, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near West Allis share this climate record?
West Milwaukee has no NOAA station with 1991-2020 normals of its own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- West Milwaukee, WI3,997 people · 2 mi E
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about West Allis's climate
What is the coldest month in West Allis?
January, with a normal high of 31°F and a normal low of 15°F. The warmest is July (85°F by day, 63°F at night).
Does it snow in West Allis?
Yes: 52 inches in a normal year, falling on 33 days with 0.1 inch or more, the most in February (13.6 inches).
What is the rainiest month in West Allis?
June, with 5.03 in of precipitation in a normal year; the driest is February with 2.15 in.
What plant hardiness zone is West Allis in?
The USDA's 2023 map puts West Allis in zone 5b across its 3 ZIP code areas (5b in 53214, the largest).
How late can frost come in West Allis?
In half of years the last 32°F night comes after April 26; in one year in ten it comes after May 12. Waiting until May 12 leaves about a one-in-ten chance of a later frost.
Nearby and next
- West Allis in OctoberThis month day by day, its records and recent years
- Wisconsin climateThe statewide normals and every place in the state
- Wauwatosa, WI4 miles from this station, 48.2°F a year
- Hales Corners, WI6 miles from this station, 47.3°F a year
- Milwaukee, WI7 miles from this station, 49.3°F a year
- Brookfield, WI9 miles from this station, 46.6°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made