Lake Mills, Wisconsin climate: Normal weather by month, frost dates and records
Lake Mills's normal year runs from 11°F January nights to 84°F July afternoons, with 37.0 inches of precipitation and 42 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.6°C, January lows of −11°C, July highs of 29°C, 939 mm of precipitation a year.
- NOAA stationLake Mills Wastewater Treatment Plant
- Station IDUSC00474482
- Location43.08°N 88.90°W
- Elevation811 ft (247 m)
- From the centerunder 1 mile
- Population6,617
On October 14, the normal high in Lake Mills is 62°F and the normal low 41°F, and the chance of measurable rain or snow is 32%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Lake Mills.
- Jan 27° 11°
- Feb 31° 14°
- Mar 43° 25°
- Apr 57° 36°
- May 70° 48°
- Jun 80° 58°
- Jul 84° 62°
- Aug 81° 61°
- Sep 74° 52°
- Oct 61° 40°
- Nov 45° 29°
- Dec 32° 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 Lake Mills each month?
July is the warmest month, with normal highs of 84°F; January the coldest, with normal lows of 11°F. The most precipitation falls in June (5.11 in), the least in January (1.41 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 27°F | 11°F | 19.1°F | 1.41 | 10.7 | 8 | <1 | 30 | 9 h 20 min |
| February | 31°F | 14°F | 22.6°F | 1.52 | 11.4 | 7 | <1 | 27 | 10 h 30 min |
| March | 43°F | 25°F | 33.9°F | 2.03 | 4.9 | 7 | <1 | 24 | 11 h 50 min |
| April | 57°F | 36°F | 46.4°F | 3.59 | 2.1 | 10 | <1 | 10 | 13 h 20 min |
| May | 70°F | 48°F | 58.6°F | 4.39 | 0.1 | 12 | 1 | 1 | 14 h 40 min |
| June | 80°F | 58°F | 69.1°F | 5.11 | 0.0 | 12 | 3 | <1 | 15 h 20 min |
| July | 84°F | 62°F | 73.0°F | 4.37 | 0.0 | 9 | 5 | <1 | 15 h 10 min |
| August | 81°F | 61°F | 70.8°F | 4.50 | 0.0 | 9 | 3 | <1 | 14 h |
| September | 74°F | 52°F | 62.9°F | 3.47 | 0.0 | 9 | 1 | <1 | 12 h 30 min |
| October | 61°F | 40°F | 50.5°F | 2.82 | 0.2 | 10 | <1 | 6 | 11 h 10 min |
| November | 45°F | 29°F | 36.9°F | 2.12 | 2.0 | 8 | <1 | 19 | 9 h 50 min |
| December | 32°F | 18°F | 25.1°F | 1.65 | 10.9 | 9 | <1 | 29 | 9 h |
| Year (annual) | 57°F | 38°F | 47.4°F | 36.98 | 42.3 | 110 | 12 | 145 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −3°C | −11°C | −7.2°C | 36 mm | 27 cm |
| February | 0°C | −10°C | −5.2°C | 39 mm | 29 cm |
| March | 6°C | −4°C | 1.1°C | 52 mm | 12 cm |
| April | 14°C | 2°C | 8.0°C | 91 mm | 5 cm |
| May | 21°C | 9°C | 14.8°C | 112 mm | 0 cm |
| June | 27°C | 15°C | 20.6°C | 130 mm | 0 cm |
| July | 29°C | 17°C | 22.8°C | 111 mm | 0 cm |
| August | 27°C | 16°C | 21.6°C | 114 mm | 0 cm |
| September | 23°C | 11°C | 17.2°C | 88 mm | 0 cm |
| October | 16°C | 5°C | 10.3°C | 72 mm | 1 cm |
| November | 7°C | −2°C | 2.7°C | 54 mm | 5 cm |
| December | 0°C | −8°C | −3.8°C | 42 mm | 28 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00474482; 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 Lake Mills?
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 USC00474482.
When is the last frost in Lake Mills?
In Lake Mills, the last spring frost (32°F) comes after April 29 in half of years and after May 13 in one year in ten; the first autumn frost comes before October 14 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
- April 291 year in 10 after May 13; 9 in 10 after April 15
- First autumn frost, half of years before
- October 141 year in 10 before September 29; 9 in 10 before October 27
NOAA puts the median frost-free season at 167 days, and the season without a hard freeze (28°F) at 190 days.
A hard freeze (28°F) comes after April 17 in half of springs and before October 26 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Lake Mills in zone 5b in ZIP code 53551. By the map's own method, the average of each year's coldest night over 1991-2020, Lake Mills's NOAA station is in zone 5b: the coldest night of a typical year reaches −14°F (20 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 USC00474482; 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.
How hot and how cold does it get in Lake Mills?
In a normal year in Lake Mills, 12 days a year reach 90°F, 145 nights fall to 32°F or colder and 110 days bring measurable precipitation.
- Days at 90°F or more
- 12a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 145a normal year
- Days that stay below freezing
- 58high of 32°F or less
- Days with 0.01 inch of precipitation
- 110a normal year
- Days with 1 inch of snow or more
- 12a normal year
The highest temperature in this station's record (since 1893) is 110°F, on July 14, 1936; the lowest is −33°F, on January 30, 1951.
The wettest calendar year on that record is 2018, with 49.23 in; the snowiest season is 2007–08, with 85.7 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00474482; records: ACIS (NOAA Regional Climate Centers), station USC00474482. Records use complete months only; a month missing more than three days is left out.
How sunny is Lake Mills?
Over a year 72% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Lake Mills, 3.8 kWh per square metre a day. July is the sunniest month (80%) and December the cloudiest (59%).
| 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 Lake Mills need?
A normal year in Lake Mills brings 7,099 heating degree days, 32% more than the median U.S. place (5,373), and 725 cooling degree days, 20% 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 2,830 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,423 | 0 |
| February | 1,187 | 0 |
| March | 965 | 1 |
| April | 559 | 3 |
| May | 241 | 43 |
| June | 37 | 160 |
| July | 4 | 251 |
| August | 13 | 193 |
| September | 132 | 68 |
| October | 457 | 7 |
| November | 845 | 0 |
| December | 1,235 | 0 |
| Year (annual) | 7,099 | 725 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00474482. 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 Lake Mills been warmer than normal lately?
2025 averaged 48.0°F, 0.6°F above the 1991-2020 normal of 47.4°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 49.4°F | +2.0°F | 28.19 | 33.9 |
| 2022 | 46.8°F | −0.6°F | 37.73 | 30.9 |
| 2023 | 49.9°F | +2.5°F | 29.19 | 48.6 |
| 2024 | 50.5°F | +3.1°F | 44.47 | 39.9 |
| 2025 | 48.0°F | +0.6°F | 29.03 | 27.4 |
Over 95 complete years from 1893 to 2025, the station's annual mean temperature rose at a fitted 1.6°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 USC00474482; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Lake Mills's climate compare?
Lake Mills is warmer than 149 of the other 164 places with their own NOAA record in Wisconsin, and wetter than 125. Across the 7,247 U.S. stations with normals, its annual mean of 47.4°F is warmer than 29%.
In the Köppen classification computed from these normals, Lake Mills 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 Lake Mills share this climate record?
3 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.
- Deerfield, WI2,647 people · 9 mi W
- Lake Ripley, WI1,972 people · 7 mi SW
- Cambridge, WI1,691 people · 8 mi SW
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 Lake Mills's climate
What is the coldest month in Lake Mills?
January, with a normal high of 27°F and a normal low of 11°F. The warmest is July (84°F by day, 62°F at night).
Does it snow in Lake Mills?
Yes: 42 inches in a normal year, falling on 24 days with 0.1 inch or more, the most in February (11.4 inches).
What is the rainiest month in Lake Mills?
June, with 5.11 in of precipitation in a normal year; the driest is January with 1.41 in.
What plant hardiness zone is Lake Mills in?
The USDA's 2023 map puts Lake Mills in zone 5b in ZIP code 53551. By the same method at Lake Mills's NOAA station, the coldest night of a typical year reaches −14°F (20 years, 1991-2020): zone 5b.
How late can frost come in Lake Mills?
In half of years the last 32°F night comes after April 29; in one year in ten it comes after May 13. Waiting until May 13 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Wisconsin climateThe statewide normals and every place in the state
- Jefferson, WI7 miles from this station, 47.2°F a year
- Waterloo, WI9 miles from this station, 46.7°F a year
- Watertown, WI11 miles from this station, 46.4°F a year
- Fort Atkinson, WI12 miles from this station, 47.2°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made