Green Bay, WI climate
Green Bay has cold, snowy winters and pleasant summers. A typical July afternoon reaches 78°, a January night drops to 13°, and about 56 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Green Bay feels like
Winter
Spring
Summer
Fall
Green Bay weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 26° | 13° | 1.5" | 14.3" | 11 | 24 | 8° – 31° |
| February | 29° | 15° | 1.2" | 12.0" | 9 | 24 | 11° – 33° |
| March | 39° | 25° | 1.9" | 8.1" | 10 | 13 | 22° – 46° |
| April | 50° | 34° | 3.0" | 4.7" | 12 | 2 | 34° – 48° |
| May | 63° | 45° | 3.5" | 0 | 12 | 0 | 47° – 59° |
| June | 73° | 55° | 4.0" | 0 | 11 | 0 | 59° – 68° |
| July | 78° | 60° | 3.7" | 0 | 11 | 0 | 63° – 75° |
| August | 77° | 60° | 3.4" | 0 | 10 | 0 | 63° – 73° |
| September | 70° | 52° | 3.3" | 0 | 10 | 0 | 55° – 66° |
| October | 57° | 41° | 2.9" | 0.3" | 10 | 0 | 44° – 55° |
| November | 43° | 30° | 2.1" | 3.1" | 10 | 3 | 28° – 44° |
| December | 32° | 20° | 1.8" | 13.1" | 11 | 17 | 13° – 36° |
| Year | 53° | 37° | 32.4" | 55.6" | 126 | 82 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Green Bay
Green Bay gets 32 inches of rain and melted snow a year. June is the wettest month and February the driest. Rain or snow falls on about 126 days a year. Snow covers the ground about 82 days of the year.
About 161 frost-free days a year
In half of years the last 32° night comes by April 30 and the first one by October 9. That leaves about 161 frost-free days for gardens, shorter than 70% of U.S. towns.
Heating and cooling a home in Green Bay
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Green Bay, 94% of that work is heating and 6% is cooling, so the furnace matters far more than the air conditioner.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
Green Bay and its neighbors
Green Bay borders 7 towns with climate data. January nights across them vary by 2.3°. Humboldt has the coldest January nights (11°) and Hobart the hottest July afternoons (80°). Green Bay’s January low is 13° and its July high 78°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Green Bay compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Green Bay averaged 2.0° warmer than the 1900s. The biggest change is in December (+3.5°). The shift is larger than in 93% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Green Bay’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. January swings the most: between 1991 and 2020 its average temperature ranged from 8° to 31°. June is the most reliable, staying within 9°.
Common questions about Green Bay’s climate
What is the coldest month in Green Bay?
January, with a typical high of 26° and a low of 13°.
What is the hottest month in Green Bay?
July, with a typical high of 78° and a low of 60°. About 6 days a year reach 90°.
How much snow does Green Bay get?
About 56 inches in a normal winter, most of it in January.
When is the first frost in Green Bay?
In half of years the first 32° night comes by October 9, and the last spring frost by April 30.
What is the rainiest month in Green Bay?
June, with 4.0 inches of rain and melted snow. The year totals 32 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Green Bay itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Green Bay, WI (6 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.