Fond du Lac, Wisconsin climate: Normal weather by month, frost dates and records
Fond du Lac's normal year runs from 11°F January nights to 82°F July afternoons, with 28.4 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.1°C, January lows of −12°C, July highs of 28°C, 721 mm of precipitation a year.
- NOAA stationFond Du Lac County Airport
- Station IDUSW00004840
- Location43.77°N 88.49°W
- Elevation809 ft (247 m)
- From the center2 miles
- Population44,469
On October 22, the normal high in Fond du Lac is 56°F and the normal low 38°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 Fond du Lac.
- Jan 27° 11°
- Feb 30° 14°
- Mar 42° 24°
- Apr 56° 35°
- May 68° 47°
- Jun 78° 57°
- Jul 82° 61°
- Aug 80° 59°
- Sep 73° 51°
- Oct 59° 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 Fond du Lac each month?
July is the warmest month, with normal highs of 82°F; January the coldest, with normal lows of 11°F. The most precipitation falls in June (4.14 in), the least in February (0.69 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. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 27°F | 11°F | 18.9°F | 0.73 | 6 | <1 | 29 | 9 h 20 min |
| February | 30°F | 14°F | 22.0°F | 0.69 | 7 | <1 | 26 | 10 h 30 min |
| March | 42°F | 24°F | 33.2°F | 1.72 | 9 | <1 | 24 | 11 h 50 min |
| April | 56°F | 35°F | 45.4°F | 2.79 | 11 | <1 | 10 | 13 h 20 min |
| May | 68°F | 47°F | 57.4°F | 3.31 | 13 | 1 | 1 | 14 h 40 min |
| June | 78°F | 57°F | 67.4°F | 4.14 | 12 | 2 | <1 | 15 h 30 min |
| July | 82°F | 61°F | 71.3°F | 3.40 | 11 | 4 | <1 | 15 h 10 min |
| August | 80°F | 59°F | 69.4°F | 3.45 | 10 | 1 | <1 | 14 h |
| September | 73°F | 51°F | 61.9°F | 2.86 | 9 | <1 | <1 | 12 h 30 min |
| October | 59°F | 40°F | 49.5°F | 2.54 | 11 | <1 | 6 | 11 h 10 min |
| November | 45°F | 29°F | 36.7°F | 1.84 | 8 | <1 | 18 | 9 h 40 min |
| December | 32°F | 18°F | 25.1°F | 0.92 | 8 | <1 | 27 | 9 h |
| Year (annual) | 56°F | 37°F | 46.5°F | 28.39 | 114 | 7 | 143 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | −3°C | −12°C | −7.3°C | 19 mm |
| February | −1°C | −10°C | −5.6°C | 18 mm |
| March | 6°C | −4°C | 0.7°C | 44 mm |
| April | 13°C | 2°C | 7.4°C | 71 mm |
| May | 20°C | 8°C | 14.1°C | 84 mm |
| June | 26°C | 14°C | 19.7°C | 105 mm |
| July | 28°C | 16°C | 21.8°C | 86 mm |
| August | 26°C | 15°C | 20.8°C | 88 mm |
| September | 23°C | 11°C | 16.6°C | 73 mm |
| October | 15°C | 4°C | 9.7°C | 65 mm |
| November | 7°C | −2°C | 2.6°C | 47 mm |
| December | 0°C | −8°C | −3.8°C | 23 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. Fond du Lac's own co-op station Fond Du Lac Wastewater Treatment Plant does: 38 inches of snow in a normal year (see the other stations below).
Source: NOAA NCEI 1991-2020 monthly normals, station USW00004840; 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 Fond du Lac?
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 USW00004840.
When is the last frost in Fond du Lac?
In Fond du Lac, the last spring frost (32°F) comes after May 1 in half of years and after May 17 in one year in ten; the first autumn frost comes before October 10 in half of years and before September 27 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 17; 9 in 10 after April 17
- First autumn frost, half of years before
- October 101 year in 10 before September 27; 9 in 10 before October 25
NOAA puts the median frost-free season at 160 days, and the season without a hard freeze (28°F) at 182 days.
A hard freeze (28°F) comes after April 21 in half of springs and before October 23 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Fond du Lac in zone 5b in ZIP code 54935. By the map's own method, the average of each year's coldest night over 1991-2020, Fond du Lac's NOAA station is in zone 5b: the coldest night of a typical year reaches −15°F (23 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 USW00004840; 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 Fond du Lac?
In a normal year in Fond du Lac, 7 days a year reach 90°F, 143 nights fall to 32°F or colder and 114 days bring measurable precipitation.
- Days at 90°F or more
- 7a 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
- 62high of 32°F or less
- Days with 0.01 inch of precipitation
- 114a normal year
The highest temperature in this station's record (since 1996) is 102°F, on July 23, 2012; the lowest is −28°F, on January 31, 2019.
The wettest calendar year on that record is 2020, with 35.92 in.
Source: NOAA NCEI 1991-2020 annual normals, station USW00004840; records: ACIS (NOAA Regional Climate Centers), station USW00004840. Records use complete months only; a month missing more than three days is left out.
How sunny is Fond du Lac?
Over a year 72% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Fond du Lac, 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 Fond du Lac need?
A normal year in Fond du Lac brings 7,275 heating degree days, 35% more than the median U.S. place (5,373), and 583 cooling degree days, 36% 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 2,600 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,429 | 0 |
| February | 1,203 | 0 |
| March | 987 | 1 |
| April | 590 | 2 |
| May | 267 | 31 |
| June | 50 | 124 |
| July | 11 | 207 |
| August | 21 | 155 |
| September | 150 | 57 |
| October | 485 | 7 |
| November | 849 | 0 |
| December | 1,235 | 0 |
| Year (annual) | 7,275 | 583 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00004840. 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 Fond du Lac been warmer than normal lately?
2025 averaged 46.3°F, 0.2°F below the 1991-2020 normal of 46.5°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 50.2°F | +3.7°F | 24.62 |
| 2022 | 46.7°F | +0.2°F | 28.27 |
| 2023 | 49.7°F | +3.2°F | 26.52 |
| 2024 | 50.0°F | +3.5°F | 33.95 |
| 2025 | 46.3°F | −0.2°F | 24.73 |
Source: observed years: ACIS, station USW00004840. A year counts only with all twelve months complete.
How does Fond du Lac's climate compare?
Fond du Lac is warmer than 118 of the other 164 places with their own NOAA record in Wisconsin, and wetter than 2. 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, Fond du Lac 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 Fond du Lac share this climate record?
8 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.
- North Fond du Lac, WI5,419 people · 3 mi N
- Lomira, WI2,671 people · 12 mi S
- St. Peter, WI1,403 people · 9 mi NE
- Oakfield, WI1,064 people · 7 mi SW
- Eden, WI904 people · 8 mi SE
- Taycheedah, WI682 people · 6 mi NE
- Brownsville, WI650 people · 11 mi S
- Mount Calvary, WI488 people · 13 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.
What do Fond du Lac's other NOAA stations record?
2 more NOAA stations keep 1991-2020 normals in or near Fond du Lac. This page uses Fond Du Lac County Airport; the others differ by site and elevation:
| Station | From the center | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Fond Du Lac (2 mi SW) USC00472842 | 1 mi W | 772 ft | 47.0°F | 12°F | 82°F | 32.4 | – | April 27 |
| Fond Du Lac Wastewater Treatment Plant USC00472839 | 2 mi N | 750 ft | 45.0°F | 9°F | 80°F | 31.4 | 38 | May 1 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Fond du Lac's climate
What is the coldest month in Fond du Lac?
January, with a normal high of 27°F and a normal low of 11°F. The warmest is July (82°F by day, 61°F at night).
Does it snow in Fond du Lac?
Yes. NOAA publishes no 1991-2020 snowfall normal for Fond du Lac's NOAA station; Fond du Lac's own co-op station Fond Du Lac Wastewater Treatment Plant records 38 inches of snow in a normal year.
What is the rainiest month in Fond du Lac?
June, with 4.14 in of precipitation in a normal year; the driest is February with 0.69 in.
What plant hardiness zone is Fond du Lac in?
The USDA's 2023 map puts Fond du Lac in zone 5b in ZIP code 54935. By the same method at Fond du Lac's NOAA station, the coldest night of a typical year reaches −15°F (23 years, 1991-2020): zone 5b.
How late can frost come in Fond du Lac?
In half of years the last 32°F night comes after May 1; in one year in ten it comes after May 17. Waiting until May 17 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Fond du Lac in OctoberThis month day by day, its records and recent years
- Wisconsin climateThe statewide normals and every place in the state
- Ripon, WI15 miles from this station, 45.1°F a year
- Oshkosh, WI16 miles from this station, 46.3°F a year
- Horicon, WI24 miles from this station, 45.2°F a year
- Chilton, WI25 miles from this station, 45.7°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made