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Average Weather in Green Bay Wisconsin, United States

In Green Bay, the temperature typically varies from 12°F to 81°F over the course of the year, and is rarely below -7°F or above 89°F.

The warm season lasts for 116 days, from May 25 to September 18, with an average daily high temperature above 69°F. The hottest day of the year is July 19, with an average high of 81°F and low of 62°F.

The cold season lasts for 99 days, from November 30 to March 9, with an average daily high temperature below 37°F. The coldest day of the year is January 29, with an average low of 12°F and high of 26°F.

Average High and Low Temperature

The daily average high (red line) and low (blue line) temperature with percentile bands, with 25th to 75th and 10th to 90th percentile bands. The thin dotted lines are the corresponding average perceived temperatures.

The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.

Average Hourly Temperature

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDecfrigidfrigidfreezingfreezingchillychillycoldcoldcoolcoolcomfortablecomfortablewarmwarm
The average hourly temperature, color coded into bands: frigid < 15°F < freezing < 32°F < chilly < 45°F < cold < 55°F < cool < 65°F < comfortable < 75°F < warm < 85°F < hot < 95°F < sweltering. The shaded overlays indicate night and civil twilight.

Sun

The length of the day in Green Bay varies significantly over the course of the year. In 2017, the shortest day is December 21, with 8 hours, 49 minutes of daylight; the longest day is June 21, with 15 hours, 33 minutes of daylight.

Hours of Daylight and Twilight

The number of hours during which the Sun is visible (black line). From bottom (most yellow) to top (most gray), the color bands indicate: full daylight, twilight (civil, nautical, and astronomical), and full night.

The earliest sunrise is at 5:06 AM on June 15, and the latest sunrise is 2 hours, 27 minutes later at 7:34 AM on November 4. The earliest sunset is at 4:12 PM on December 9, and the latest sunset is 4 hours, 29 minutes later at 8:41 PM on June 26.

Daylight saving time (DST) is observed in Green Bay during 2017, starting in the spring on March 12, lasting 237 days, and ending in the fall on November 5.

Sunrise & Sunset with Twilight and Daylight Saving Time

The solar day over the course of the year 2017. From bottom to top, the black lines are the previous solar midnight, sunrise, solar noon, sunset, and the next solar midnight. The day, twilights (civil, nautical, and astronomical), and night are indicated by the color bands from yellow to gray. The transitions to and from daylight saving time are indicated by the 'DST' labels.

Clouds

In Green Bay, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.

The clearer part of the year in Green Bay begins around June 7 and lasts for 137 days, ending around October 22. On August 7, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 67% of the time, and overcast or mostly cloudy 33% of the time.

The cloudier part of the year begins around October 22 and lasts for 228 days, ending around June 7. On January 26, the cloudiest day of the year, the sky is overcast or mostly cloudy 61% of the time, and clear, mostly clear, or partly cloudy 39% of the time.

Cloud Cover

clearerclearercloudiercloudiercloudiercloudier0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecJan 2661%Jan 2661%Aug 733%Aug 733%Jun 747%Jun 747%Oct 2247%Oct 2247%overcastovercastmostly cloudymostly cloudypartly cloudypartly cloudymostly clearmostly clearclearclear
The percentage of time spent in each cloud cover band, categorized by the percentage of the sky covered by clouds: clear < 20% < mostly clear < 40% < partly cloudy < 60% < mostly cloudy < 80% < overcast.

Precipitation

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Green Bay varies throughout the year.

The wetter season lasts 189 days, from April 5 to October 11, with a greater than 25% chance of a given day being a wet day. The chance of a wet day peaks at 38% on June 8.

The drier season lasts 176 days, from October 11 to April 5. The smallest chance of a wet day is 12% on February 2.

Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation in Green Bay changes throughout the year.

Rain alone is the most common for 297 days, from February 25 to December 19. The highest chance of a day with rain alone is 38% on June 8.

Snow alone is the most common for 68 days, from December 19 to February 25. The highest chance of a day with snow alone is 9% on January 19.

Daily Chance of Precipitation

The percentage of days in which various types of precipitation are observed, excluding trace quantities: rain alone, snow alone, and mixed (both rain and snow fell in the same day).

Rainfall

To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day in the year. Green Bay experiences significant seasonal variation in monthly rainfall.

The rainy period of the year lasts for 322 days, from February 17 to January 5, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around June 15, with an average total accumulation of 3.6 inches.

The rainless period of the year lasts for 43 days, from January 5 to February 17. The least rain falls around January 28, with and average total accumulation of 0.4 inches.

Average Monthly Rainfall

The average rainfall (solid line) accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average liquid-equivalent snowfall.

Snowfall

We report snowfall in liquid-equivalent terms. The actual depth of new snowfall is typically between 5 and 10 times the liquid-equivalent amount, assuming the ground is frozen. Colder, drier snow tends to be on the higher end of that range and warmer, wetter snow on the lower end.

As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day in the year. Green Bay experiences some seasonal variation in monthly liquid-equivalent snowfall.

The snowy period of the year lasts for 155 days, from November 10 to April 14, with a sliding 31-day liquid-equivalent snowfall of at least 0.1 inches. The most snow falls during the 31 days centered around January 5, with an average total liquid-equivalent accumulation of 0.5 inches.

The snowless period of the year lasts for 210 days, from April 14 to November 10. The least snow falls around July 27, with an average total liquid-equivalent accumulation of 0.0 inches.

Average Liquid-Equivalent Monthly Snowfall

The average liquid-equivalent snowfall (solid line) accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average rainfall.

Humidity

We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.

Green Bay experiences significant seasonal variation in the perceived humidity.

The muggier period of the year lasts for 101 days, from June 8 to September 17, during which time the comfort level is muggy, oppressive, or miserable at least 8% of the time. The muggiest day of the year is July 31, with muggy conditions 31% of the time.

The least muggy day of the year is February 27, when muggy conditions are essentially unheard of.

Humidity Comfort Levels

muggymuggy0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecFeb 270%Feb 270%Jul 3131%Jul 3131%Jun 88%Jun 88%Sep 178%Sep 178%muggymuggycomfortablecomfortabledrydrymiserablemiserable
The percentage of time spent at various humidity comfort levels, categorized by dew point: dry < 55°F < comfortable < 60°F < humid < 65°F < muggy < 70°F < oppressive < 75°F < miserable.

Wind

This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.

The average hourly wind speed in Green Bay experiences mildly seasonal variation over the course of the year.

The windier part of the year lasts for 232 days, from September 21 to May 11, with average wind speeds of more than 6.1 miles per hour. The windiest day of the year is January 14, with an average hourly wind speed of 7.3 miles per hour.

The calmer time of year lasts for 133 days, from May 11 to September 21. The calmest day of the year is August 3, with an average hourly wind speed of 4.9 miles per hour.

Average Wind Speed

The average of mean hourly wind speeds (dark gray line), with 25th to 75th and 10th to 90th percentile bands.

The predominant average hourly wind direction in Green Bay varies throughout the year.

The wind is most often from the north for 52 days, from March 1 to April 22, with a peak percentage of 34% on March 8. The wind is most often from the south for 46 days, from April 28 to June 13 and for 30 days, from August 21 to September 20, with a peak percentage of 34% on September 6. The wind is most often from the west for 69 days, from June 13 to August 21 and for 162 days, from September 20 to March 1, with a peak percentage of 47% on December 13.

Wind Direction

WWNNSSWWSSWW0%20%40%60%80%100%JanFebMarAprMayJunJulAugSepOctNovDecwestwestsouthsoutheasteastnorthnorth
The percentage of hours in which the mean wind direction is from each of the four cardinal wind directions (north, east, south, and west), excluding hours in which the mean wind speed is less than 1 mph. The lightly tinted areas at the boundaries are the percentage of hours spent in the implied intermediate directions (northeast, southeast, southwest, and northwest).

Water Temperature

Green Bay is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.

The average water temperature experiences significant seasonal variation over the course of the year.

The time of year with warmer water lasts for 76 days, from July 10 to September 24, with an average temperature above 62°F. The day of the year with the warmest water is August 17, with an average temperature of 69°F.

The time of year with cooler water lasts for 157 days, from December 5 to May 11, with an average temperature below 41°F. The day of the year with the coolest water is March 11, with an average temperature of 34°F.

Average Water Temperature

The daily average water temperature (purple line) with percentile bands, with 25th to 75th and 10th to 90th percentile bands.

Solar Energy

This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.

The average daily incident shortwave solar energy experiences very significant seasonal variation over the course of the year.

The brighter period of the year lasts for 108 days, from May 4 to August 20, with an average daily incident shortwave energy per square meter above 5.8 kWh. The brightest day of the year is July 1, with an average of 7.0 kWh.

The darker period of the year lasts for 108 days, from October 28 to February 13, with an average daily incident shortwave energy per square meter below 2.6 kWh. The darkest day of the year is December 22, with an average of 1.4 kWh.

Average Daily Incident Shortwave Solar Energy

The average daily shortwave solar energy reaching the ground per square meter (orange line), with 25th to 75th and 10th to 90th percentile bands.

Topography

For the purposes of this report, the geographical coordinates of Green Bay are 44.519 deg latitude, -88.020 deg longitude, and 587 ft elevation (map ).

The topography within 2 miles of Green Bay is essentially flat, with a maximum elevation change of 79 feet, and an average elevation above sea level of 591 feet. Within 10 miles contains only modest variations in elevation (374 feet). Within 50 miles contains significant variations in elevation (656 feet).

The area within 2 miles of Green Bay is covered by artificial surfaces (96%), within 10 miles by cropland (43%) and artificial surfaces (28%), and within 50 miles by cropland (47%) and water (28%).

Data Sources

This report illustrates the typical weather in Green Bay, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.

Temperature and Dew Point

There are 3 weather stations near enough to contribute to our estimation of the temperature and dew point in Green Bay.

For each station, the records are corrected for the elevation difference between that station and Green Bay according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.

The estimated value at Green Bay is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Green Bay and a given station.

The stations contributing to this reconstruction are: Austin Straubel International Airport (85%, 10 kilometers, southwest), Manitowoc County Airport (8%, 51 kilometers, southeast), and Door County Cherryland Airport (6%, 60 kilometers, northeast).

Other Data

All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , by Jean Meeus.

All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.

Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.

Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.

Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .

Time zones for aiports and weather stations are provided by AskGeo.com .