This report describes the typical weather at the Dane County Regional Airport (Madison, Wisconsin, United States) weather station over the course of an average year. It is based on the historical records from 1974 to 2012. Earlier records are either unavailable or unreliable.
Madison, Wisconsin has a humid continental climate with hot summers and no dry season. The area within 25 mi of this station is covered by grasslands (49%), croplands (45%), and lakes and rivers (3%).
Over the course of a year, the temperature typically varies from 10°F to 83°F and is rarely below -8°F or above 90°F.
The warm season lasts from May 22 to September 17 with an average daily high temperature above 71°F. The hottest day of the year is July 14, with an average high of 83°F and low of 62°F.
The cold season lasts from November 28 to March 3 with an average daily high temperature below 37°F. The coldest day of the year is January 17, with an average low of 10°F and high of 26°F.
The length of the day varies significantly over the course of the year. The shortest day is December 21 with 9:00 hours of daylight; the longest day is June 20 with 15:23 hours of daylight.
The earliest sunrise is at 5:17am on June 15 and the latest sunset is at 8:42pm on June 26. The latest sunrise is at 7:36am on November 3 and the earliest sunset is at 4:22pm on December 10.
Daylight savings time (DST) is observed in this location during 2012, starting in the spring on March 11 and ending in the fall on November 4.
The median cloud cover ranges from 42% (partly cloudy) to 91% (mostly cloudy). The sky is cloudiest on December 18 and clearest on July 17. The clearer part of the year begins around May 2. The cloudier part of the year begins around October 24.
On July 17, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 65% of the time, and overcast or mostly cloudy 34% of the time.
On December 18, the cloudiest day of the year, the sky is overcast, mostly cloudy, or partly cloudy 66% of the time, and clear or mostly clear 34% of the time.
The probability that precipitation will be observed at this location varies throughout the year. Precipitation is most likely around December 26, occurring in 62% of days. Precipitation is least likely around September 30, occurring in 41% of days.
Over the entire year, the most common forms of precipitation are light snow, light rain, thunderstorms, and moderate rain.
Light snow is the most severe precipitation observed during 28% of those days with precipitation. It is most likely around January 15, when it is observed during 41% of all days.
Light rain is the most severe precipitation observed during 24% of those days with precipitation. It is most likely around May 13, when it is observed during 20% of all days.
Thunderstorms are the most severe precipitation observed during 19% of those days with precipitation. They are most likely around July 10, when it is observed during 22% of all days.
Moderate rain is the most severe precipitation observed during 16% of those days with precipitation. It is most likely around May 7, when it is observed during 12% of all days.
During the warm season, which lasts from May 22 to September 17, there is a 45% average chance that precipitation will be observed at some point during a given day. When precipitation does occur it is most often in the form of thunderstorms (42% of days with precipitation have at worst thunderstorms), light rain (31%), and moderate rain (22%).
During the cold season, which lasts from November 28 to March 3, there is a 58% average chance that precipitation will be observed at some point during a given day. When precipitation does occur it is most often in the form of light snow (61% of days with precipitation have at worst light snow), moderate snow (16%), light rain (8%), and moderate rain (6%).
The likelihood of snow falling is highest around January 15, occurring in 53% of days. The season in which it is relatively likely for snow to fall spans from November 4 to April 6.
During peak snow season, accumulation at this location on a given day is likely. The chances of there being snow on the ground are highest around February 2, occurring 82% of the time. The season in which snow is relatively likely to be on the ground spans from November 27 to March 22.
The snow is typically at its deepest on January 30, with a median depth of 5.0"; the depth exceeds 11.7" only one year out of ten.
The relative humidity typically ranges from 42% (comfortable) to 95% (very humid) over the course of the year, rarely dropping below 24% (dry) and reaching as high as 100% (very humid).
The air is driest around May 1, at which time the relative humidity drops below 49% (comfortable) three days out of four; it is most humid around August 13, exceeding 92% (very humid) three days out of four.
Dew point is often a better measure of how comfortable a person will find the weather than relative humidity because it more directly relates to whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid.
Over the course of a year, the dew point typically varies from 4°F (dry) to 66°F (muggy) and is rarely below -16°F (dry) or above 74°F (very muggy).
There are two periods in the year that are most comfortable: The first is between May 13 and July 9 and the second is between August 8 and October 2. The air feels neither too dry nor too muggy during these periods.
Over the course of the year typical wind speeds vary from 0 mph to 18 mph (calm to fresh breeze), rarely exceeding 25 mph (strong breeze).
The highest average wind speed of 11 mph (gentle breeze) occurs around April 7, at which time the average daily maximum wind speed is 18 mph (moderate breeze).
The lowest average wind speed of 7 mph (light breeze) occurs around August 6, at which time the average daily maximum wind speed is 13 mph (moderate breeze).