Waukesha, Wisconsin climate: Normal weather by month, frost dates and records
Waukesha's normal year runs from 12°F January nights to 81°F July afternoons, with 36.0 inches of precipitation and 37 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.1°C, January lows of −11°C, July highs of 27°C, 913 mm of precipitation a year.
- NOAA stationWaukesha Wastewater Treatment Plant
- Station IDUSC00478937
- Location43.01°N 88.25°W
- Elevation789 ft (241 m)
- Population71,461
On October 14, the normal high in Waukesha is 61°F and the normal low 41°F, and the chance of measurable rain or snow is 31%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Waukesha.
- Jan 28° 12°
- Feb 32° 15°
- Mar 43° 24°
- Apr 55° 35°
- May 67° 46°
- Jun 77° 56°
- Jul 81° 60°
- Aug 80° 59°
- Sep 73° 51°
- Oct 60° 40°
- Nov 45° 28°
- Dec 33° 18°
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 Waukesha each month?
July is the warmest month, with normal highs of 81°F; January the coldest, with normal lows of 12°F. The most precipitation falls in June (4.88 in), the least in January (1.60 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 | 28°F | 12°F | 19.7°F | 1.60 | 10.4 | 9 | <1 | 30 | 9 h 20 min |
| February | 32°F | 15°F | 23.0°F | 1.71 | 10.1 | 8 | <1 | 26 | 10 h 30 min |
| March | 43°F | 24°F | 33.5°F | 1.93 | 4.6 | 8 | <1 | 24 | 11 h 50 min |
| April | 55°F | 35°F | 45.1°F | 3.65 | 1.1 | 11 | <1 | 10 | 13 h 20 min |
| May | 67°F | 46°F | 56.6°F | 3.97 | 0.0 | 13 | <1 | 1 | 14 h 40 min |
| June | 77°F | 56°F | 66.5°F | 4.88 | 0.0 | 11 | 3 | <1 | 15 h 20 min |
| July | 81°F | 60°F | 70.9°F | 3.99 | 0.0 | 9 | 4 | <1 | 15 h |
| August | 80°F | 59°F | 69.4°F | 4.18 | 0.0 | 9 | 3 | <1 | 14 h |
| September | 73°F | 51°F | 62.0°F | 3.27 | 0.0 | 9 | 1 | <1 | 12 h 30 min |
| October | 60°F | 40°F | 49.9°F | 2.92 | 0.1 | 10 | <1 | 6 | 11 h 10 min |
| November | 45°F | 28°F | 36.7°F | 2.15 | 1.8 | 9 | <1 | 19 | 9 h 50 min |
| December | 33°F | 18°F | 25.5°F | 1.70 | 8.8 | 9 | <1 | 28 | 9 h |
| Year (annual) | 56°F | 37°F | 46.5°F | 35.95 | 36.9 | 115 | 11 | 143 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −2°C | −11°C | −6.8°C | 41 mm | 26 cm |
| February | 0°C | −10°C | −5.0°C | 43 mm | 26 cm |
| March | 6°C | −4°C | 0.8°C | 49 mm | 12 cm |
| April | 13°C | 2°C | 7.3°C | 93 mm | 3 cm |
| May | 20°C | 8°C | 13.7°C | 101 mm | 0 cm |
| June | 25°C | 13°C | 19.2°C | 124 mm | 0 cm |
| July | 27°C | 16°C | 21.6°C | 101 mm | 0 cm |
| August | 27°C | 15°C | 20.8°C | 106 mm | 0 cm |
| September | 23°C | 11°C | 16.7°C | 83 mm | 0 cm |
| October | 16°C | 4°C | 9.9°C | 74 mm | 0 cm |
| November | 7°C | −2°C | 2.6°C | 55 mm | 5 cm |
| December | 1°C | −8°C | −3.6°C | 43 mm | 22 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00478937; 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 Waukesha?
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 USC00478937.
When is the last frost in Waukesha?
In Waukesha, the last spring frost (32°F) comes after May 1 in half of years and after May 18 in one year in ten; the first autumn frost comes before October 13 in half of years and before September 29 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
- May 11 year in 10 after May 18; 9 in 10 after April 18
- First autumn frost, half of years before
- October 131 year in 10 before September 29; 9 in 10 before October 25
NOAA puts the median frost-free season at 162 days, and the season without a hard freeze (28°F) at 185 days.
A hard freeze (28°F) comes after April 19 in half of springs and before October 23 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Waukesha in zone 5b across its 3 ZIP code areas (5b in 53188, the largest). By the map's own method, the average of each year's coldest night over 1991-2020, Waukesha's NOAA station is in zone 5b: the coldest night of a typical year reaches −11°F (16 complete years).
Frost dates for every NOAA station in Wisconsin · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00478937; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. 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 Waukesha ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. Waukesha'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 Waukesha?
In a normal year in Waukesha, 11 days a year reach 90°F, 143 nights fall to 32°F or colder and 115 days bring measurable precipitation.
- Days at 90°F or more
- 11a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 143a normal year
- Days that stay below freezing
- 58high of 32°F or less
- Days with 0.01 inch of precipitation
- 115a normal year
- Days with 1 inch of snow or more
- 13a normal year
The highest temperature in this station's record (since 1894) is 109°F, on July 14, 1936; the lowest is −28°F, on February 3, 1996.
The wettest calendar year on that record is 2013, with 45.17 in; the snowiest season is 2007–08, with 85.4 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00478937; records: ACIS (NOAA Regional Climate Centers), station USC00478937. Records use complete months only; a month missing more than three days is left out.
How sunny is Waukesha?
Over a year 72% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Waukesha, 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 Waukesha need?
A normal year in Waukesha brings 7,247 heating degree days, 35% more than the median U.S. place (5,373), and 559 cooling degree days, 38% 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 2,535 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,406 | 0 |
| February | 1,174 | 0 |
| March | 977 | 0 |
| April | 600 | 2 |
| May | 287 | 25 |
| June | 71 | 116 |
| July | 14 | 195 |
| August | 22 | 157 |
| September | 148 | 57 |
| October | 474 | 6 |
| November | 851 | 0 |
| December | 1,223 | 0 |
| Year (annual) | 7,247 | 559 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00478937. 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 Waukesha been warmer than normal lately?
2025 averaged 46.5°F, equal to the 1991-2020 normal of 46.5°F.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2025 | 46.5°F | at normal | 37.62 | 29.2 |
Over 85 complete years from 1896 to 2025, the station's annual mean temperature rose at a fitted 1.7°F per century (+0.09°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00478937; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Waukesha's climate compare?
Waukesha is warmer than 118 of the other 164 places with their own NOAA record in Wisconsin, and wetter than 110. Across the 7,247 U.S. stations with normals, its annual mean of 46.5°F is warmer than 25%.
In the Köppen classification computed from these normals, Waukesha is Dfb: continental, no dry season, warm 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 Waukesha share this climate record?
5 places have no NOAA station with 1991-2020 normals of their 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.
- Hartland, WI10,203 people · 8 mi NW
- Waukesha, WI8,573 people · 3 mi S
- Vernon, WI7,505 people · 9 mi S
- Wales, WI2,913 people · 6 mi W
- Big Bend, WI1,502 people · 9 mi S
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 Waukesha's climate
What is the coldest month in Waukesha?
January, with a normal high of 28°F and a normal low of 12°F. The warmest is July (81°F by day, 60°F at night).
Does it snow in Waukesha?
Yes: 37 inches in a normal year, falling on 24 days with 0.1 inch or more, the most in January (10.4 inches).
What is the rainiest month in Waukesha?
June, with 4.88 in of precipitation in a normal year; the driest is January with 1.60 in.
What plant hardiness zone is Waukesha in?
The USDA's 2023 map puts Waukesha in zone 5b across its 3 ZIP code areas (5b in 53188, the largest). By the same method at Waukesha's NOAA station, the coldest night of a typical year reaches −11°F (16 years, 1991-2020): zone 5b.
How late can frost come in Waukesha?
In half of years the last 32°F night comes after May 1; in one year in ten it comes after May 18. Waiting until May 18 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Waukesha in OctoberThis month day by day, its records and recent years
- Wisconsin climateThe statewide normals and every place in the state
- Brookfield, WI5 miles from this station, 46.6°F a year
- Wauwatosa, WI12 miles from this station, 48.2°F a year
- Hales Corners, WI12 miles from this station, 47.3°F a year
- West Allis, WI12 miles from this station, 49.1°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made