Port Washington, Wisconsin climate: Normal weather by month, frost dates and records
Port Washington's normal year runs from 15°F January nights to 79°F July afternoons, with 33.9 inches of precipitation and 42 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.2°C, January lows of −10°C, July highs of 26°C, 861 mm of precipitation a year.
- NOAA stationPort Washington
- Station IDUSC00476764
- Location43.39°N 87.86°W
- Elevation594 ft (181 m)
- Population12,750
On October 24, the normal high in Port Washington is 56°F and the normal low 39°F, and the chance of measurable rain or snow is 29%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Port Washington.
- Jan 31° 15°
- Feb 34° 16°
- Mar 42° 25°
- Apr 51° 35°
- May 61° 45°
- Jun 72° 55°
- Jul 79° 62°
- Aug 78° 62°
- Sep 71° 54°
- Oct 59° 42°
- Nov 46° 31°
- 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 Port Washington each month?
July is the warmest month, with normal highs of 79°F; January the coldest, with normal lows of 15°F. The most precipitation falls in June (4.17 in), the least in February (1.48 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 31°F | 15°F | 22.7°F | 1.76 | 13.2 | 8 | <1 | 29 | 9 h 20 min |
| February | 34°F | 16°F | 24.6°F | 1.48 | 10.7 | 7 | <1 | 26 | 10 h 30 min |
| March | 42°F | 25°F | 33.7°F | 1.91 | 6.0 | 8 | <1 | 24 | 11 h 50 min |
| April | 51°F | 35°F | 43.2°F | 3.78 | 0.8 | 10 | <1 | 8 | 13 h 20 min |
| May | 61°F | 45°F | 53.0°F | 3.90 | 0.0 | 11 | <1 | <1 | 14 h 40 min |
| June | 72°F | 55°F | 63.2°F | 4.17 | 0.0 | 10 | 1 | <1 | 15 h 20 min |
| July | 79°F | 62°F | 70.1°F | 3.61 | 0.0 | 9 | 2 | <1 | 15 h 10 min |
| August | 78°F | 62°F | 70.0°F | 3.68 | 0.0 | 8 | 2 | <1 | 14 h |
| September | 71°F | 54°F | 62.5°F | 3.08 | 0.0 | 8 | <1 | <1 | 12 h 30 min |
| October | 59°F | 42°F | 50.4°F | 2.56 | 0.0 | 9 | <1 | 3 | 11 h 10 min |
| November | 46°F | 31°F | 38.5°F | 2.13 | 0.9 | 8 | <1 | 16 | 9 h 40 min |
| December | 36°F | 21°F | 28.2°F | 1.82 | 10.7 | 8 | <1 | 27 | 9 h |
| Year (annual) | 55°F | 38°F | 46.7°F | 33.88 | 42.3 | 103 | 5 | 133 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −1°C | −10°C | −5.2°C | 45 mm | 34 cm |
| February | 1°C | −9°C | −4.1°C | 38 mm | 27 cm |
| March | 5°C | −4°C | 0.9°C | 49 mm | 15 cm |
| April | 11°C | 2°C | 6.2°C | 96 mm | 2 cm |
| May | 16°C | 7°C | 11.7°C | 99 mm | 0 cm |
| June | 22°C | 13°C | 17.3°C | 106 mm | 0 cm |
| July | 26°C | 16°C | 21.2°C | 92 mm | 0 cm |
| August | 26°C | 16°C | 21.1°C | 93 mm | 0 cm |
| September | 22°C | 12°C | 16.9°C | 78 mm | 0 cm |
| October | 15°C | 5°C | 10.2°C | 65 mm | 0 cm |
| November | 8°C | −1°C | 3.6°C | 54 mm | 2 cm |
| December | 2°C | −6°C | −2.1°C | 46 mm | 27 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00476764; 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 Port Washington?
Normal highs sit between 65°F and 85°F in June, July, August and September. Of those, September has the fewest days with rain (8).
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 USC00476764.
When is the last frost in Port Washington?
In Port Washington, the last spring frost (32°F) comes after April 27 in half of years and after May 14 in one year in ten; the first autumn frost comes before October 22 in half of years and before October 6 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 271 year in 10 after May 14; 9 in 10 after April 11
- First autumn frost, half of years before
- October 221 year in 10 before October 6; 9 in 10 before November 4
NOAA puts the median frost-free season at 176 days, and the season without a hard freeze (28°F) at 202 days.
A hard freeze (28°F) comes after April 13 in half of springs and before November 2 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Port Washington in zone 5b in ZIP code 53074. By the map's own method, the average of each year's coldest night over 1991-2020, Port Washington's NOAA station is in zone 5b: the coldest night of a typical year reaches −10°F (19 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 USC00476764; 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 Port Washington?
In a normal year in Port Washington, 5 days a year reach 90°F, 133 nights fall to 32°F or colder and 103 days bring measurable precipitation.
- Days at 90°F or more
- 5a 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
- 51high of 32°F or less
- Days with 0.01 inch of precipitation
- 103a normal year
- Days with 1 inch of snow or more
- 12a normal year
The highest temperature in this station's record (since 1893) is 106°F, on July 13, 1995; the lowest is −29°F, on February 8, 1899.
The wettest calendar year on that record is 2008, with 44.24 in; the snowiest season is 2007–08, with 80.6 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00476764; records: ACIS (NOAA Regional Climate Centers), station USC00476764. Records use complete months only; a month missing more than three days is left out.
How sunny is Port Washington?
Over a year 70% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Port Washington, 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 Port Washington need?
A normal year in Port Washington brings 7,113 heating degree days, 32% more than the median U.S. place (5,373), and 467 cooling degree days, 49% 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 2,305 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,311 | 0 |
| February | 1,131 | 0 |
| March | 972 | 0 |
| April | 654 | 0 |
| May | 376 | 6 |
| June | 117 | 61 |
| July | 16 | 174 |
| August | 14 | 169 |
| September | 129 | 54 |
| October | 454 | 2 |
| November | 795 | 0 |
| December | 1,142 | 0 |
| Year (annual) | 7,113 | 467 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00476764. 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.
How does Port Washington's climate compare?
Port Washington is warmer than 130 of the other 164 places with their own NOAA record in Wisconsin, and wetter than 58. Across the 7,247 U.S. stations with normals, its annual mean of 46.7°F is warmer than 26%.
In the Köppen classification computed from these normals, Port Washington 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.
Questions about Port Washington's climate
What is the coldest month in Port Washington?
January, with a normal high of 31°F and a normal low of 15°F. The warmest is July (79°F by day, 62°F at night).
Does it snow in Port Washington?
Yes: 42 inches in a normal year, falling on 20 days with 0.1 inch or more, the most in January (13.2 inches).
What is the rainiest month in Port Washington?
June, with 4.17 in of precipitation in a normal year; the driest is February with 1.48 in.
What plant hardiness zone is Port Washington in?
The USDA's 2023 map puts Port Washington in zone 5b in ZIP code 53074. By the same method at Port Washington's NOAA station, the coldest night of a typical year reaches −10°F (19 years, 1991-2020): zone 5b.
How late can frost come in Port Washington?
In half of years the last 32°F night comes after April 27; in one year in ten it comes after May 14. Waiting until May 14 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Wisconsin climateThe statewide normals and every place in the state
- Saukville, WI4 miles from this station, 45.0°F a year
- Grafton, WI7 miles from this station, 47.9°F a year
- Belgium, WI8 miles from this station, 45.1°F a year
- Jackson, WI16 miles from this station, 46.7°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made