Climateby Month

Green Bay, WI climate by month

NOAA 1991-2020 normals · 593 ft elevation

Summers in Green Bay are warm; winters are very cold and snowy. Highs peak at 81°F in July and fall to 26°F in January. Wet days are spread through the year, from about 9 to 12 a month. Normal snowfall is about 56 in a year. The most comfortable time to visit is May, June and September.

Warmest month
81°F
July normal high
Coldest month
11°F
January normal low
Wet days a year
126
31.6 in of precipitation
Snow a year
55.6 in
normal snowfall

How warm is Green Bay?

Normal highs range from 26°F in January to 81°F in July.

0°20°40°60°80°100° January: normal high 26°F (-3°C), low 11°F (-12°C) 26° 11° February: normal high 29°F (-2°C), low 13°F (-11°C) March: normal high 40°F (4°C), low 24°F (-4°C) April: normal high 54°F (12°C), low 35°F (2°C) May: normal high 67°F (19°C), low 46°F (8°C) June: normal high 77°F (25°C), low 56°F (13°C) July: normal high 81°F (27°C), low 60°F (16°C) 81° 60° August: normal high 79°F (26°C), low 58°F (14°C) September: normal high 72°F (22°C), low 50°F (10°C) October: normal high 58°F (14°C), low 40°F (4°C) November: normal high 44°F (7°C), low 29°F (-2°C) December: normal high 31°F (-1°C), low 18°F (-8°C) JFMAMJJASOND

Bars run from the normal low to the normal high for each month.

How rainy is Green Bay?

May has the most wet days (about 12); the year brings about 32 in of precipitation.

January: 11 wet days February: 9 wet days 9 March: 10 wet days April: 12 wet days May: 12 wet days 12 June: 11 wet days July: 11 wet days August: 10 wet days September: 10 wet days October: 10 wet days November: 10 wet days December: 11 wet days JFMAMJJASOND

Wet day: at least 0.01 in of rain or melted snow, counted from daily records 1991-2020.

How much does it snow?

Normal snowfall is 55.6 in a year, most of it in January.

January: 14.3 in of snow 14.3 February: 12.0 in of snow March: 8.1 in of snow April: 4.7 in of snow May: 0.0 in of snow 0.0 June: 0.0 in of snow July: 0.0 in of snow August: 0.0 in of snow September: 0.0 in of snow October: 0.3 in of snow November: 3.1 in of snow December: 13.1 in of snow JFMAMJJASOND

How humid is Green Bay?

Muggy days peak in July, at about 9 days.

January: 0 muggy days 0 February: 0 muggy days March: 0 muggy days April: 0 muggy days May: 1 muggy days June: 4 muggy days July: 9 muggy days 9 August: 7 muggy days September: 2 muggy days October: 0 muggy days November: 0 muggy days December: 0 muggy days JFMAMJJASOND

Muggy day: daily mean dew point of 65°F or higher, from hourly observations 1991-2020 at Austin Straubel International Airport, 6.4 mi WSW of the city center.

How much daylight?

Daylight ranges from about 8.9 hours in December to 15.5 hours in June.

January: 9.3 hours of daylight February: 10.5 hours of daylight March: 11.9 hours of daylight April: 13.5 hours of daylight May: 14.8 hours of daylight June: 15.5 hours of daylight 15.5 July: 15.2 hours of daylight August: 14.0 hours of daylight September: 12.5 hours of daylight October: 11.0 hours of daylight November: 9.6 hours of daylight December: 8.9 hours of daylight 8.9 JFMAMJJASOND
See all numbers
Monthly climate normals and day counts for Green Bay, 1991-2020
MonthHighLowPrecip.Wet daysSnowMuggy daysDaylight
January 26°F11°F 1.4 in11 14.3 in 0 9.3 h
February 29°F13°F 1.2 in9 12.0 in 0 10.5 h
March 40°F24°F 2.0 in10 8.1 in 0 11.9 h
April 54°F35°F 3.0 in12 4.7 in 0 13.5 h
May 67°F46°F 3.4 in12 0.0 in 1 14.8 h
June 77°F56°F 4.1 in11 0.0 in 4 15.5 h
July 81°F60°F 3.6 in11 0.0 in 9 15.2 h
August 79°F58°F 3.4 in10 0.0 in 7 14.0 h
September 72°F50°F 3.2 in10 0.0 in 2 12.5 h
October 58°F40°F 2.7 in10 0.3 in 0 11.0 h
November 44°F29°F 2.0 in10 3.1 in 0 9.6 h
December 31°F18°F 1.8 in11 13.1 in 0 8.9 h

High and low: NOAA 1991-2020 normal daily high and low. Wet days: at least 0.01 in of rain or melted snow. Muggy days: daily mean dew point 65°F or higher.

Best months to visit Green Bay

By our comfort score, the best months are May, June and September.

Comfort score by month (0-100) and its parts, in days per month
MonthScoreComfortableNotable rainHot or cold
Jan 230429
Feb 280425
Mar 391517
Apr 54574
May 711470
Jun 711482
Jul 661073
Aug 671261
Sep 691560
Oct 54761
Nov 361512
Dec 250526

Score = 40 × share of comfortable days + 25 × share of days without notable rain + 20 × share of days neither hot (90°F+) nor cold (high 40°F or below) + 15 × daylight. How the score works.

Frost dates in Green Bay

The last spring frost typically comes around Apr 30, and the first fall frost around Oct 9, leaving 161 frost-free days in a typical year.

Frost and freeze dates for Green Bay
Typical date1 year in 10
Last spring frost (32°F)Apr 30after May 16
First fall frost (32°F)Oct 9before Sep 24
Last hard freeze (28°F)Apr 17after May 4
First hard freeze (28°F)Oct 24before Oct 6
Frost-free season161 daysunder 141 days

"Typical" is the date with a 50% chance of a later spring frost (or earlier fall frost). Planting after the "1 year in 10" spring date gives a 90% chance of no further frost. The Old Farmer's Almanac publishes 30% dates, which fall between our typical and 1-in-10 dates.

Station: Green Bay (USW00014898), NOAA 1991-2020 freeze probabilities. Frost dates for every city in Wisconsin.

Hottest and coldest readings, 1991-2020

The highest reading was 103°F (July 13, 1995); the lowest was -28°F (January 19, 1994).

From the temperature station's daily records with NOAA quality flags removed. Not an all-time record.

Near Green Bay

Similar climates elsewhere

Where the numbers come from

  • Temperature, rain, snowfall, snow depth, frost dates, humidity and wind by hour and cloud cover: Green Bay (USW00014898), 4.7 mi WSW of the city center, 682 ft (89 ft higher than the city). NOAA normals and daily records, 1991-2020.
  • Daily humidity and wind: Austin Straubel International Airport (726450-14898), 6.4 mi WSW of the city center, 684 ft (91 ft higher than the city). Hourly observations, 1991-2020.

Distances from the city center (USGS). Methodology · Report an error