Plymouth, Wisconsin climate: Normal weather by month, frost dates and records
Plymouth's normal year runs from 12°F January nights to 81°F July afternoons, with 33.6 inches of precipitation and 45 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 7.6°C, January lows of −11°C, July highs of 27°C, 853 mm of precipitation a year.
- NOAA stationPlymouth Wastewater Treatment Plant
- Station IDUSC00476678
- Location43.73°N 87.97°W
- Elevation828 ft (252 m)
- From the center1 miles
- Population8,854
On October 14, the normal high in Plymouth is 59°F and the normal low 40°F, and the chance of measurable rain or snow is 34%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Plymouth.
- Jan 26° 12°
- Feb 30° 14°
- Mar 41° 24°
- Apr 53° 34°
- May 66° 45°
- Jun 76° 55°
- Jul 81° 60°
- Aug 79° 59°
- Sep 72° 51°
- Oct 58° 39°
- Nov 44° 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 Plymouth 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 (4.22 in), the least in February (1.41 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 26°F | 12°F | 18.9°F | 1.59 | 12.4 | 9 | <1 | 30 | 9 h 20 min |
| February | 30°F | 14°F | 21.7°F | 1.41 | 11.0 | 9 | <1 | 27 | 10 h 30 min |
| March | 41°F | 24°F | 32.0°F | 1.97 | 5.9 | 9 | <1 | 25 | 11 h 50 min |
| April | 53°F | 34°F | 43.7°F | 3.63 | 2.1 | 11 | <1 | 12 | 13 h 20 min |
| May | 66°F | 45°F | 55.5°F | 3.83 | 0.2 | 13 | <1 | 1 | 14 h 40 min |
| June | 76°F | 55°F | 65.4°F | 4.22 | 0.0 | 12 | 2 | <1 | 15 h 30 min |
| July | 81°F | 60°F | 70.6°F | 3.50 | 0.0 | 11 | 3 | <1 | 15 h 10 min |
| August | 79°F | 59°F | 68.7°F | 3.69 | 0.0 | 10 | 2 | <1 | 14 h |
| September | 72°F | 51°F | 61.1°F | 2.81 | 0.0 | 9 | <1 | <1 | 12 h 30 min |
| October | 58°F | 39°F | 48.8°F | 2.96 | 0.1 | 11 | <1 | 7 | 11 h 10 min |
| November | 44°F | 29°F | 36.3°F | 2.14 | 2.3 | 9 | <1 | 20 | 9 h 40 min |
| December | 32°F | 18°F | 25.2°F | 1.82 | 10.7 | 9 | <1 | 28 | 9 h |
| Year (annual) | 55°F | 37°F | 45.7°F | 33.57 | 44.7 | 121 | 7 | 151 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −3°C | −11°C | −7.3°C | 40 mm | 31 cm |
| February | −1°C | −10°C | −5.7°C | 36 mm | 28 cm |
| March | 5°C | −5°C | 0.0°C | 50 mm | 15 cm |
| April | 12°C | 1°C | 6.5°C | 92 mm | 5 cm |
| May | 19°C | 7°C | 13.1°C | 97 mm | 1 cm |
| June | 24°C | 13°C | 18.6°C | 107 mm | 0 cm |
| July | 27°C | 16°C | 21.4°C | 89 mm | 0 cm |
| August | 26°C | 15°C | 20.4°C | 94 mm | 0 cm |
| September | 22°C | 10°C | 16.2°C | 71 mm | 0 cm |
| October | 15°C | 4°C | 9.3°C | 75 mm | 0 cm |
| November | 7°C | −2°C | 2.4°C | 54 mm | 6 cm |
| December | 0°C | −8°C | −3.8°C | 46 mm | 27 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00476678; 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 Plymouth?
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 USC00476678.
When is the last frost in Plymouth?
In Plymouth, the last spring frost (32°F) comes after May 3 in half of years and after May 20 in one year in ten; the first autumn frost comes before October 10 in half of years and before September 28 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 31 year in 10 after May 20; 9 in 10 after April 19
- First autumn frost, half of years before
- October 101 year in 10 before September 28; 9 in 10 before October 25
NOAA puts the median frost-free season at 159 days, and the season without a hard freeze (28°F) at 183 days.
A hard freeze (28°F) comes after April 20 in half of springs and before October 23 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Plymouth in zone 5b in ZIP code 53073, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Plymouth's NOAA station is in zone 5b: the coldest night of a typical year reaches −13°F (28 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 USC00476678; 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 Plymouth?
In a normal year in Plymouth, 7 days a year reach 90°F, 151 nights fall to 32°F or colder and 121 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
- 151a normal year
- Days that stay below freezing
- 65high of 32°F or less
- Days with 0.01 inch of precipitation
- 121a normal year
- Days with 1 inch of snow or more
- 14a normal year
The highest temperature in this station's record (since 1910) is 107°F, on July 14, 1936; the lowest is −29°F, on January 15, 1972.
The wettest calendar year on that record is 1973, with 45.51 in; the snowiest season is 1978–79, with 105.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00476678; records: ACIS (NOAA Regional Climate Centers), station USC00476678. Records use complete months only; a month missing more than three days is left out.
How sunny is Plymouth?
Over a year 70% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Plymouth, 3.7 kWh per square metre a day. July is the sunniest month (80%) and December the cloudiest (53%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 54% | 1.4 |
| February | 60% | 2.3 |
| March | 66% | 3.5 |
| April | 68% | 4.6 |
| May | 70% | 5.4 |
| June | 75% | 6.0 |
| July | 80% | 6.1 |
| August | 79% | 5.2 |
| September | 77% | 4.2 |
| October | 67% | 2.6 |
| November | 62% | 1.7 |
| December | 53% | 1.2 |
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 Plymouth need?
A normal year in Plymouth brings 7,518 heating degree days, 40% more than the median U.S. place (5,373), and 511 cooling degree days, 44% fewer than the median (908). Eight months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,391 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,427 | 0 |
| February | 1,212 | 0 |
| March | 1,022 | 0 |
| April | 641 | 2 |
| May | 318 | 22 |
| June | 85 | 97 |
| July | 20 | 193 |
| August | 30 | 144 |
| September | 164 | 48 |
| October | 504 | 4 |
| November | 861 | 0 |
| December | 1,234 | 0 |
| Year (annual) | 7,518 | 511 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00476678. 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 Plymouth been warmer than normal lately?
2025 averaged 45.6°F, 0.1°F below the 1991-2020 normal of 45.7°F. 3 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 47.4°F | +1.6°F | 28.65 | 31.3 |
| 2022 | 44.8°F | −0.9°F | 31.71 | 34.0 |
| 2023 | 47.8°F | +2.1°F | 31.09 | 57.5 |
| 2024 | 48.5°F | +2.8°F | 40.18 | 44.6 |
| 2025 | 45.6°F | −0.1°F | 26.19 | 37.2 |
Over 98 complete years from 1911 to 2025, the station's annual mean temperature rose at a fitted 2.2°F per century (+0.12°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00476678; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Plymouth's climate compare?
Plymouth is warmer than 94 of the other 164 places with their own NOAA record in Wisconsin, and wetter than 49. Across the 7,247 U.S. stations with normals, its annual mean of 45.7°F is warmer than 22%.
In the Köppen classification computed from these normals, Plymouth 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 Plymouth 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.
- Elkhart Lake, WI1,102 people · 7 mi N
- Cascade, WI709 people · 5 mi S
- St. Cloud, WI493 people · 12 mi NW
- Glenbeulah, WI453 people · 6 mi NW
- Greenbush, WI122 people · 7 mi NW
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 Plymouth's climate
What is the coldest month in Plymouth?
January, with a normal high of 26°F and a normal low of 12°F. The warmest is July (81°F by day, 60°F at night).
Does it snow in Plymouth?
Yes: 45 inches in a normal year, falling on 27 days with 0.1 inch or more, the most in January (12.4 inches).
What is the rainiest month in Plymouth?
June, with 4.22 in of precipitation in a normal year; the driest is February with 1.41 in.
What plant hardiness zone is Plymouth in?
The USDA's 2023 map puts Plymouth in zone 5b in ZIP code 53073, the nearest ZIP area. By the same method at Plymouth's NOAA station, the coldest night of a typical year reaches −13°F (28 years, 1991-2020): zone 5b.
How late can frost come in Plymouth?
In half of years the last 32°F night comes after May 3; in one year in ten it comes after May 20. Waiting until May 20 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Wisconsin climateThe statewide normals and every place in the state
- Sheboygan, WI7 miles from this station, 45.2°F a year
- Hingham, WI7 miles from this station, 45.9°F a year
- Belgium, WI16 miles from this station, 45.1°F a year
- Chilton, WI22 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