Climate and monthly weather forecastGreen Bay, WI
Climate and monthly weather forecast
The climate of Green Bay
Green Bay, located in the state of Wisconsin USA, falls under the Dfb category of the Köppen climate classification. This category is characterized as a humid continental climate with moderate populations of both flora and fauna. The key features of this climate include no dry season and warm summers.Weather patterns across the year display significant variations due to the continental influence. The monthly temperature highs in Green Bay range from 22.6°F (-5.2°C) in January to 78.1°F (25.6°C) in July whereas the lows fluctuate between 12.4°F (-10.9°C) in January and 60.4°F (15.8°C) in July. This broadly reflects the changing conditions from the cold winter months to the warmer summer period.
Relative humidity, an indicator of the air's moisture content, is fairly high throughout the year, with the least humid month being April at 76%, escalating up to a high of 88% during January. Rainfall occurs consistently year-round amounting from 1.18" (30mm) in January to a peak of 3.31" (84mm) in May. However, snowfall is concentrated in the colder months, from a high of 5.79" (147mm) in February, reducing to negligible quantities between May and September before starting to accumulate again in October.
The amount of daylight experienced in Green Bay fluctuates noticeably with the progression of the seasons. January sees an average of 9.3 hours of daylight, increasing to a peak of 15.5 hours in June. The associated sunshine hours, indicating bright and clear skies, range from a low of 3.4 hours in January to a remarkable high of 10.1 hours in July.
The best time to visit Green Bay
The optimal time to visit Green Bay would be during the summer months from June to August. The temperatures are pleasantly warm, averaging between 50.2°F (10.1°C) to 77°F (25°C). With 15.5 hours of daylight in June and high average sunshine hours (9.3 hours in June), it offers ample opportunity for sightseeing and outdoor activities.The worst time to visit Green Bay
The harshest months in Green Bay are typically in winter, specifically from December to February. Temperatures during this period can drop as low as 12.4°F (-10.9°C) in January, coupled with significant snowfall. These chilly conditions can prove too harsh for those unaccustomed to intense winter environments.Spring weather in Green Bay
Examples of comfortable climates can be seen in Green Bay during spring from March to May; it sees a steady climb in temperatures, ranging from 38.5°F (3.6°C) to 63.3°F (17.4°C), and a rise in daylight hours. Rainfall also starts to intensify during these months, reaching a peak at 3.31" (84mm) in May, indicating the start of the city's wet season.Summer weather in Green Bay
Summer in Green Bay, ushered in June and stretching until August, is generally warmer with temperatures peaking at around 78.1°F (25.6°C) in July. Relative humidity remains steady, providing some cooling relief. The hours of sunshine and daylight are at their highest, allowing for ample opportunities for outdoor activities.Autumn weather in Green Bay
Autumn in Green Bay, from September to November, brings about a gradual drop in temperatures from 69.6°F (20.9°C) in September to 41.7°F (5.4°C) in November. This period also witnesses a decrease in rainfall to around 1.57" (40mm) by November, making it relatively drier compared to other seasons.Winter weather in Green Bay
Winter in Green Bay, from December to February, is starkly cold with average high temperatures hovering between 22.6°F (-5.2°C) to 28.8°F (-1.8°C). These months also see an escalation in snowfall, peaking at 5.79" (147mm) in February. Reduced daylight hours and low sunshine hours make this season appear gloomy. Visitors during these months should prepare for freezing temperatures and heavily overcast skies.Weather in January
Green Bay, Wisconsin, witnesess some of its coldest days in January, as temperatures generally range from a low of 12.4°F (-10.9°C) to a high of 22.6°F (-5.2°C). With overcast skies being a common sight, the rays of sunshine are limited to an average of just 3.5 hours per day. Weather in January »Weather in February
As Green Bay transitions through February, slight moderation in temperatures can be observed, yet winters still grip the city. The days grow longer, and the city witnesses daylight for 10.5 hours on average. Though temperatures start to rise marginally, February records an average snowfall of 5.79" (147mm). Weather in February »Weather in March
The onset of spring in March brings a respite from harsh winter temperatures in Green Bay, with significant rise in temperatures alongside an increase in rainfall. Average highs and lows for the month range from 25.5°F (-3.6°C) to 38.5°F (3.6°C) making the weather slightly more endurable. Weather in March »Weather in April
April comes with a pronounced change in weather, with the mercury rising above 50°F (10°C) during the daytime. April also introduces more rainfall to Green Bay, with an average monthly rainfall of 2.56" (65mm). Along with this, there’s a noticeable lengthening in daylight hours and an increase in the number of sunshine hours. Weather in April »Weather in May
May brings about a considerable rise in temperature, transforming Green Bay into sun-filled spaces with temperatures maxing between 63.3°F (17.4°C). With the onset of a warmer climate, the ice starts to melt and the chances of snowfall dwindle significantly to almost none. Weather in May »Weather in June
June ushers in the season of summer in Green Bay, with longest daylight hours of the year and increased sunshine duration. The warm temperature, ranging to about 72.1°F (22.3°C) as the average high, marks the beginning of a short but vibrant summer season. Weather in June »Weather in July
July is when Green Bay experiences the height of summer, with temperatures soaring to an average high of 78.1°F (25.6°C) making it the hottest month of the year. Despite the heat, the city maintains relatively high humidity levels, making the heat slightly more oppressive. Weather in July »Weather in August
As August rolls in, there is a slight dip in temperature from July’s peak but the city continues to bask under summer's radiance. With highs only slightly dropping to 77°F (25°C), August continues to feel like the heart of summer. Weather in August »Weather in September
September signals the onset of fall in Green Bay, with a gradual tapering of temperatures. The sky remains clear for most of the month, and the city enjoys 8.4 hours of average daily sunshine. It also marks a transition from warm to mildly cool weather, hinting at the approaching winter with temperatures dropping to an average 52.3°F (11.3°C) towards the end of the month. Weather in September »Weather in October
October witnesses a noticeable drop in temperature, and the vibrant hues of fall are in full display in Green Bay. With decreasing daylight hours, the longer and cooler nights make their presence felt. The weather during October is notorious for its unpredictability with temperatures oscillating between highs of 55.8°F (13.2°C) and lows around 41.9°F (5.5°C). Weather in October »Weather in November
Contrasting the relatively mild October, November in Green Bay is a prelude to the harsh winter, and the temperatures plunge significantly. The cooling temperatures give way to more frequent snowfall, with an average of 1.5" (38mm) falling in November. Weather in November »Weather in December
December is dominated by cold temperatures and snowfall, prepping Green Bay for the deep winter ahead. With an average snowfall of 4.76" (121mm), December ranks second in snowfall accumulation, next only to January. The daylight hours drop to a mere 8.9 hours, the shortest in the year, with sun shining for only around 3.6 hours a day on average. Weather in December »Updated: Aug 24, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
January, with an average high of 22.6°F (-5.2°C) and a low of 12.4°F (-10.9°C), signifies the coldest month of the year.
The most humid month is January, with an average relative humidity of 88%.
January is the month with the least rainfall. Rain falls for 4.6 days and accumulates 1.18" (30mm) of precipitation.
Throughout the year, there are 130.8 rainfall days, and 24.8" (630mm) of precipitation is accumulated.
January through May, October through December are months with snowfall.
In Green Bay, during the entire year, snow falls for 63.7 days and aggregates up to 23.27" (591mm) of snow.
January, February, November and December, with an average maximum UV index of 1, are months with the lowest UV index.
The month with the most snowfall in Green Bay is February, when snow falls for 13.9 days and typically aggregates up to 5.79" (147mm) of snow.
February is the month with the coldest seawater, with an average ocean temperature of 36.1°F (2.3°C).
The month with the least sunshine in Green Bay is February, with an average of 3.4h of sunshine.
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from CST to CDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from CDT to CST.
April and May, with an average relative humidity of 76%, are the least humid months.
The month with the most rainfall is May, when the rain falls for 15.9 days and typically aggregates up to 3.31" (84mm) of precipitation.
June through September are months without snowfall.
The month with the longest days is June, with an average of 15h and 30min of daylight.
The months with the highest UV index are June through August, with an average maximum UV index of 5.
July stands out as Green Bay's warmest month, with temperatures ranging between an average high of 78.1°F (25.6°C) and a low of 60.4°F (15.8°C).
The month with the most sunshine is July, with an average of 10.1h of sunshine.
With an average ocean temperature of 67.6°F (19.8°C), August is the month with the warmest seawater.
December has the shortest days of the year, with an average of 8h and 54min of daylight.
Average temperature
Green Bay, WI
The warmest month (with the highest average high temperature) is July (78.1°F).
The month with the lowest average high temperature is January (22.6°F).
The month with the highest average low temperature is July (60.4°F).
The coldest month (with the lowest average low temperature) is January (12.4°F).
Average pressure
Green Bay, WI
- Average pressure in January:
30.08"Hg - Average pressure in February:
30.08"Hg - Average pressure in March:
30.09"Hg - Average pressure in April:
29.97"Hg - Average pressure in May:
29.96"Hg - Average pressure in June:
29.91"Hg
- Average pressure in July:
29.95"Hg - Average pressure in August:
29.96"Hg - Average pressure in September:
30.02"Hg - Average pressure in October:
29.98"Hg - Average pressure in November:
30.06"Hg - Average pressure in December:
30.07"Hg
The month with the highest atmospheric pressure is March (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed
Green Bay, WI
- Average wind speed in January:
10.1mph - Average wind speed in February:
10.1mph - Average wind speed in March:
9.4mph - Average wind speed in April:
9.8mph - Average wind speed in May:
8.7mph - Average wind speed in June:
7.7mph
- Average wind speed in July:
7.2mph - Average wind speed in August:
7.2mph - Average wind speed in September:
8.1mph - Average wind speed in October:
9.5mph - Average wind speed in November:
9.9mph - Average wind speed in December:
9.9mph
The windiest months (with the highest average wind speed) are January and February (10.1mph).
The calmest months (with the lowest average wind speed) are July and August (7.2mph).
Average humidity
Green Bay, WI
The month with the highest relative humidity is January (88%).
The months with the lowest relative humidity are April and May (76%).
Average rainfall
Green Bay, WI
- Average rainfall in January:
1.18" - Average rainfall in February:
1.3" - Average rainfall in March:
1.73" - Average rainfall in April:
2.56" - Average rainfall in May:
3.31" - Average rainfall in June:
2.68"
- Average rainfall in July:
2.56" - Average rainfall in August:
1.93" - Average rainfall in September:
1.57" - Average rainfall in October:
2.68" - Average rainfall in November:
1.57" - Average rainfall in December:
1.73"
The wettest month (with the highest rainfall) is May (3.31").
The driest month (with the least rainfall) is January (1.18").
Average rainfall days
Green Bay, WI
- Average rainfall days in January:
4.6 days - Average rainfall days in February:
3.7 days - Average rainfall days in March:
9.2 days - Average rainfall days in April:
14 days - Average rainfall days in May:
15.9 days - Average rainfall days in June:
15 days
- Average rainfall days in July:
15.6 days - Average rainfall days in August:
14.3 days - Average rainfall days in September:
11.6 days - Average rainfall days in October:
12.1 days - Average rainfall days in November:
8.3 days - Average rainfall days in December:
6.5 days
The month with the highest number of rainy days is May (15.9 days).
The month with the least rainy days is February (3.7 days).
Average snowfall
Green Bay, WI
- Average snowfall in January:
4.8" - Average snowfall in February:
5.79" - Average snowfall in March:
3.15" - Average snowfall in April:
2.72" - Average snowfall in May:
0.24" - Average snowfall in June:
0"
The month with the highest snowfall is February (5.79").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days
Green Bay, WI
- Average snowfall days in January:
15.9 days - Average snowfall days in February:
13.9 days - Average snowfall days in March:
9.6 days - Average snowfall days in April:
4.3 days - Average snowfall days in May:
0.2 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
1 days - Average snowfall days in November:
5.2 days - Average snowfall days in December:
13.6 days
The month with the highest number of snowfall days is January (15.9 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average sea temperature
Green Bay, WI
The best month for swimming (with the highest average sea temperature) is August (67.6°F).
The coldest month (with the lowest average sea temperature) is February (36.1°F).
Average daylight / Average sunshine
Green Bay, WI
- Average daylight in January:
9h and 18min - Average daylight in February:
10h and 30min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 30min - Average daylight in May:
14h and 48min - Average daylight in June:
15h and 30min
- Average daylight in July:
15h and 12min - Average daylight in August:
14h and 0min - Average daylight in September:
12h and 30min - Average daylight in October:
11h and 0min - Average daylight in November:
9h and 36min - Average daylight in December:
8h and 54min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in January:
3h and 30min - Average sunshine in February:
3h and 24min - Average sunshine in March:
5h and 30min - Average sunshine in April:
7h and 12min - Average sunshine in May:
8h and 48min - Average sunshine in June:
9h and 18min
- Average sunshine in July:
10h and 6min - Average sunshine in August:
9h and 48min - Average sunshine in September:
8h and 24min - Average sunshine in October:
5h and 12min - Average sunshine in November:
4h and 48min - Average sunshine in December:
3h and 36min
The month with the most sunshine is July (Average sunshine: 10h and 6min).
The month with the least sunshine is February (Average sunshine: 3h and 24min).
Average sunshine days
Green Bay, WI
- Average sunshine days in January:
13.2 days - Average sunshine days in February:
11.9 days - Average sunshine days in March:
14.3 days - Average sunshine days in April:
11.6 days - Average sunshine days in May:
13.3 days - Average sunshine days in June:
13.6 days
- Average sunshine days in July:
12.3 days - Average sunshine days in August:
13.9 days - Average sunshine days in September:
17 days - Average sunshine days in October:
15.2 days - Average sunshine days in November:
17 days - Average sunshine days in December:
13.9 days
The months with the most sunshine days are September and November (17 days).
The month with the least sunshine days is April (11.6 days).
Average UV index
Green Bay, WI
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 1).
Average cloud cover
Green Bay, WI
The month with the most cloud cover is January (Cloud cover 65).
The months with the least cloud cover are July and August (Cloud cover 33).
Average visibility
Green Bay, WI
The months with the highest visibility are March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January and February (5mi).
