Green Bay, WI Climate & Monthly Averages
Green Bay has a humid continental climate. July is the hottest month, averaging 82° by day; January is the coldest at 27°.
Winter sets the pace in Green Bay
Seasons are the whole story in Green Bay. The gap between an average July and an average January is 29°C - warm summers and cold, often snowy winters - which in practice means 82°F (28°C) afternoons at one end of the calendar and 27°F (-3°C) at the other.
July
82° by day 64° at nightJanuary
27° by day 14° at nightThe cold-weather pattern in numbers
Overnight lows average at or below freezing for 5 months, November through March. January is the coolest month, with highs of 27°F (-3°C) and lows near 14°F (-10°C). At its warmest, in July, Green Bay runs to 82°F (28°C) in the afternoon and back to 64°F (18°C) by dawn. Four of the twelve months pair mild highs with fewer than twelve wet days; the longest unbroken run is May through June.
Snow falls on roughly 23 days a year, mostly November through April. The gridded 2015-2024 daily record for this location tops out at 99°F (37°C) and bottoms at -24°F (-31°C) - decade extremes, not all-time station records.
More climate facts for Green Bay
- Hottest month: July - highs near 82°F (28°C)
- Coldest month: January - highs near 27°F (-3°C)
- Decade extremes (2015-2024): 99°F (37°C) high · -24°F (-31°C) low
- Wettest month: July (11 rainy days) · Sunniest: July (12.7 h sun/day)
- Climate type: humid continental
- Annual swing: 29°C between the average warmest and coolest month · day to night: 9°C
- Snow: about 23 days a year
- Months with freezing average lows: 5
- Average humidity: 70%
From snow season to the warmest stretch in Green Bay
Spring (March through May)
Through spring, Green Bay runs cool rather than cold: 54°F (12°C) by day, 36°F (2°C) after dark, and rain falls on around 34 of the 90 days, plus about 6 snowy days.
Summer (June through August)
Summer is pleasantly warm here - highs near 79°F (26°C), nights near 62°F (16°C), and rain falls on around 34 of the 90 days. Daylight is generous - around 12.0 hours of sun a day.
Fall (September through November)
Through fall, Green Bay is crisp but comfortable: 59°F (15°C) by day, 44°F (7°C) after dark, and expect showers on roughly 27 days across the season, plus about 2 snowy days.
Winter (December through February)
Winter in Green Bay brings deep cold, with daytime highs averaging 30°F (-1°C) and nights around 16°F (-9°C); expect showers on roughly 23 days across the season, plus about 14 snowy days. Wind sharpens cold like this considerably; pair the forecast winds with the wind speed converter to judge exposed conditions.
The coldest and warmest values in the dataset
Derived from ERA5 reanalysis data, 2015–2024. Official station records may differ. Need another precipitation unit? Use the rainfall converter.
Planning around winter in Green Bay
The easier weather window
May to September is the sweet spot for Green Bay - these are the warmest and brightest weeks of the year. Expect 76°F (24°C) in the afternoon and around 11 days of rain in a typical month of it. For the same question asked the other way round, see where else is warm in May.
Cold-weather packing
Pack for Green Bay with light clothing for the warm months, a heavy insulated coat, hat and gloves for winter and a compact umbrella or rain shell. July nights average 64°F (18°C), so evenings rarely match the afternoons.
Monthly highs, lows and seasonal change
| Month | High | Low | Rain days | Precipitation | Sunshine | Daylight | Wet-day chance | Humidity |
|---|---|---|---|---|---|---|---|---|
| January | 27° | 14° | 7 | 1.5 in | 5.2 h/day | 9.2 h | 24% | 76% |
| February | 30° | 13° | 7 | 1.4 in | 7.2 h/day | 10.4 h | 25% | 71% |
| March | 42° | 25° | 10 | 2.6 in | 8.1 h/day | 11.8 h | 31% | 67% |
| April | 53° | 35° | 13 | 3.5 in | 8.9 h/day | 13.4 h | 42% | 66% |
| May | 67° | 48° | 11 | 3.7 in | 10.6 h/day | 14.8 h | 36% | 65% |
| June | 77° | 59° | 11 | 3.8 in | 11.9 h/day | 15.5 h | 36% | 66% |
| July | 82° | 64° | 11 | 3.8 in | 12.7 h/day | 15.2 h | 36% | 68% |
| August | 79° | 63° | 11 | 3.8 in | 11.3 h/day | 14.0 h | 37% | 71% |
| September | 73° | 57° | 9 | 2.8 in | 9.7 h/day | 12.4 h | 31% | 73% |
| October | 59° | 44° | 11 | 3.3 in | 7.1 h/day | 10.9 h | 35% | 71% |
| November | 45° | 31° | 7 | 2.1 in | 6.1 h/day | 9.5 h | 23% | 70% |
| December | 33° | 21° | 8 | 2.3 in | 4.6 h/day | 8.8 h | 27% | 75% |
The route from winter to summer, month by month
Each card shows the average high and low. The bar places that month between Green Bay's coldest night and warmest afternoon.
January
- Rain
- 7 days
- Sunshine
- 5.2 h
- Daylight
- 9.2 h
- Snow
- 5 days
February
- Rain
- 7 days
- Sunshine
- 7.2 h
- Daylight
- 10.4 h
- Snow
- 4 days
March
- Rain
- 10 days
- Sunshine
- 8.1 h
- Daylight
- 11.8 h
- Snow
- 4 days
April
- Rain
- 13 days
- Sunshine
- 8.9 h
- Daylight
- 13.4 h
- Snow
- 2 days
May
- Rain
- 11 days
- Sunshine
- 10.6 h
- Daylight
- 14.8 h
June
- Rain
- 11 days
- Sunshine
- 11.9 h
- Daylight
- 15.5 h
July
- Rain
- 11 days
- Sunshine
- 12.7 h
- Daylight
- 15.2 h
August
- Rain
- 11 days
- Sunshine
- 11.3 h
- Daylight
- 14.0 h
September
- Rain
- 9 days
- Sunshine
- 9.7 h
- Daylight
- 12.4 h
October
- Rain
- 11 days
- Sunshine
- 7.1 h
- Daylight
- 10.9 h
November
- Rain
- 7 days
- Sunshine
- 6.1 h
- Daylight
- 9.5 h
- Snow
- 2 days
December
- Rain
- 8 days
- Sunshine
- 4.6 h
- Daylight
- 8.8 h
- Snow
- 5 days
Looking for warmer alternatives? Browse warm places by month, or compare Green Bay's coolest part of the year: January, February, December.
Where Green Bay sits among other climates
- Green Bay averages 47°F (8°C) across the year - cooler than all but 5% of the 3496 cities we track.
- Its warmest and coolest months are 29°C apart - a wider seasonal swing than 95% of the 3496 cities we track.
These comparisons use the same ten-year window for every city in the dataset.