This report describes the typical weather at the Dane County Regional Airport (Madison, Wisconsin, United States) weather station over the course of an average August. 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%).
The month of August is characterized by gradually falling daily high temperatures, with daily highs around 79°F throughout the month, exceeding 89°F or dropping below 69°F only one day in ten.
Over the course of August, the length of the day is decreasing. From the start to the end of the month, the length of the day decreases by 1:19 hours, implying an average day-over-day decrease of 2.5 minutes.
The shortest day of the month is August 31 with 13:12 hours of daylight; the longest day is August 1 with 14:30 hours of daylight.
The earliest sunrise is at 5:48am on August 1; the latest sunset is at 8:18pm on August 1; the latest sunrise is at 6:21am on August 31; the earliest sunset is at 7:33pm on August 31.
Daylight savings time is observed in 2012 but it neither starts nor ends in August, so the entire month is in daylight time.
The median cloud cover is 44% (partly cloudy) and does not vary substantially over the course of the month.
On August 16, a representative day, the sky is clear or mostly clear 46% of the time, partly cloudy 17% of the time, and mostly cloudy or overcast 36% of the time.
The average probability that some form of precipitation will be observed in a given day is 43%, with little variation over the course of the month.
Throughout August, the most common forms of precipitation are thunderstorms, light rain, and moderate rain.
Thunderstorms are the most severe precipitation observed during 43% of those days with precipitation. They are most likely around August 2, when it is observed during 21% of all days.
Light rain is the most severe precipitation observed during 29% of those days with precipitation. It is most likely around August 31, when it is observed during 14% of all days.
Moderate rain is the most severe precipitation observed during 23% of those days with precipitation. It is most likely around August 30, when it is observed during 11% of all days.
Either snow is exceptionally unlikely to fall at this location in August or this station does not reliably report precipitation types.
The relative humidity typically ranges from 52% (mildly humid) to 95% (very humid) over the course of a typical August, rarely dropping below 38% (comfortable) and reaching as high as 100% (very humid).
The air is driest around August 1, at which time the relative humidity drops below 59% (mildly humid) three days out of four; it is most humid around August 13, rising above 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 typical August, the dew point typically varies from 53°F (very comfortable) to 66°F (muggy) and is rarely below 45°F (dry) or above 73°F (very muggy).
The time of the month between August 8 and August 31 is the most comfortable, with dew points that are neither too dry nor too muggy.
Over the course of August typical wind speeds vary from 0 mph to 13 mph (calm to moderate breeze), rarely exceeding 18 mph (fresh breeze).
The highest average wind speed of 7 mph (light breeze) occurs around August 31, at which time the average daily maximum wind speed is 13 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).