This report describes the typical weather at the Watertown Municipal Airport (Watertown, Wisconsin, United States) weather station over the course of an average year. It is based on the historical records from 1995 to 2012. Earlier records are either unavailable or unreliable.
Watertown, 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 (66%), croplands (30%), and lakes and rivers (2%).
Over the course of a year, the temperature typically varies from 12Â°F to 82Â°F and is rarely below -4Â°F or above 89Â°F.
The warm season lasts from May 26 to September 21 with an average daily high temperature above 71Â°F. The hottest day of the year is July 24, with an average high of 82Â°F and low of 63Â°F.
The cold season lasts from December 1 to March 4 with an average daily high temperature below 38Â°F. The coldest day of the year is January 20, with an average low of 12Â°F and high of 26Â°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 5:14am on June 14 and the latest sunset is at 8:39pm on June 26. The latest sunrise is at 7:33am on November 3 and the earliest sunset is at 4:19pm on December 9.
Daylight saving 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 18% (mostly clear) to 81% (mostly cloudy). The sky is cloudiest on December 27 and clearest on July 13. The clearer part of the year begins around March 29. The cloudier part of the year begins around November 2.
On July 13, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 66% of the time, and overcast or mostly cloudy 24% of the time.
On December 27, the cloudiest day of the year, the sky is overcast, mostly cloudy, or partly cloudy 58% 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 30, occurring in 53% of days. Precipitation is least likely around September 21, occurring in 36% of days.
Over the entire year, the most common forms of precipitation are moderate rain, light snow, light rain, and heavy rain.
Moderate rain is the most severe precipitation observed during 28% of those days with precipitation. It is most likely around May 18, when it is observed during 19% of all days.
Light snow is the most severe precipitation observed during 26% of those days with precipitation. It is most likely around January 1, when it is observed during 35% of all days.
Light rain is the most severe precipitation observed during 22% of those days with precipitation. It is most likely around May 11, when it is observed during 16% of all days.
Heavy rain is the most severe precipitation observed during 12% of those days with precipitation. It is most likely around May 29, when it is observed during 11% of all days.
During the warm season, which lasts from May 26 to September 21, there is a 41% 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 moderate rain (39% of days with precipitation have at worst moderate rain), light rain (34%), and heavy rain (23%).
During the cold season, which lasts from December 1 to March 4, there is a 49% 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 (19%), moderate rain (10%), and light rain (5%).
The likelihood of snow falling is highest around January 18, occurring in 45% of days. The season in which it is relatively likely for snow to fall spans from November 9 to April 2.
Either snow rarely accumulates at this location or snow depth measurements are unavailable or unreliable.
The relative humidity typically ranges from 44% (comfortable) to 96% (very humid) over the course of the year, rarely dropping below 19% (dry) and reaching as high as 100% (very humid).
The air is driest around April 19, at which time the relative humidity drops below 56% (mildly humid) three days out of four; it is most humid around July 26, exceeding 93% (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 7Â°F (dry) to 71Â°F (muggy) and is rarely below -12Â°F (dry) or above 78Â°F (oppressive).
There are two periods in the year that are most comfortable: The first is between May 7 and June 16 and the second is between September 1 and October 11. 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 16 mph (calm to moderate breeze), rarely exceeding 24 mph (fresh breeze).
The highest average wind speed of 9 mph (gentle breeze) occurs around April 7, at which time the average daily maximum wind speed is 16 mph (moderate breeze).
The lowest average wind speed of 4 mph (light breeze) occurs around August 6, at which time the average daily maximum wind speed is 11 mph (gentle breeze).