This report describes the typical weather at the Peterborough Airport (Peterborough, Ontario, Canada) weather station over the course of an average year. It is based on the historical records from 1994 to 2012. Earlier records are either unavailable or unreliable.
Peterborough, Ontario has a humid continental climate with warm summers and no dry season. The area within 25 mi of this station is covered by croplands (45%), forests (41%), lakes and rivers (7%), oceans and seas (4%), and grasslands (2%).
Over the course of a year, the temperature typically varies from 8Â°F to 79Â°F and is rarely below -11Â°F or above 86Â°F.
The warm season lasts from May 27 to September 20 with an average daily high temperature above 68Â°F. The hottest day of the year is July 23, with an average high of 79Â°F and low of 58Â°F.
The cold season lasts from December 3 to March 9 with an average daily high temperature below 36Â°F. The coldest day of the year is January 23, with an average low of 8Â°F and high of 25Â°F.
The length of the day varies significantly over the course of the year. The shortest day is December 21 with 8:52 hours of daylight; the longest day is June 20 with 15:31 hours of daylight.
The earliest sunrise is at 5:29am on June 15 and the latest sunset is at 9:02pm on June 25. The latest sunrise is at 7:53am on November 3 and the earliest sunset is at 4:34pm on December 11.
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 32% (mostly clear) to 88% (mostly cloudy). The sky is cloudiest on December 16 and clearest on August 9. The clearer part of the year begins around March 19. The cloudier part of the year begins around October 19.
On August 9, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 63% of the time, and overcast or mostly cloudy 29% of the time.
On December 16, the cloudiest day of the year, the sky is overcast, mostly cloudy, or partly cloudy 68% of the time, and clear or mostly clear 25% of the time.
The probability that precipitation will be observed at this location varies throughout the year. Precipitation is most likely around January 14, occurring in 51% of days. Precipitation is least likely around August 22, occurring in 28% of days.
Over the entire year, the most common forms of precipitation are light rain, light snow, and moderate rain.
Light rain is the most severe precipitation observed during 34% of those days with precipitation. It is most likely around October 6, when it is observed during 19% of all days.
Light snow is the most severe precipitation observed during 31% of those days with precipitation. It is most likely around January 17, when it is observed during 35% of all days.
Moderate rain is the most severe precipitation observed during 14% of those days with precipitation. It is most likely around October 6, when it is observed during 9% of all days.
During the warm season, which lasts from May 27 to September 20, there is a 31% 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 rain (47% of days with precipitation have at worst light rain), moderate rain (23%), thunderstorms (18%), and heavy rain (8%).
During the cold season, which lasts from December 3 to March 9, there is a 48% 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 (63% of days with precipitation have at worst light snow), light rain (14%), and moderate snow (13%).
The likelihood of snow falling is highest around January 19, occurring in 45% of days. The season in which it is relatively likely for snow to fall spans from November 11 to April 6.
During peak snow season, accumulation at this location on a given day is just less likely than not. The chances of there being snow on the ground are highest around February 10, occurring 42% of the time. The season in which snow is relatively likely to be on the ground spans from November 26 to April 1.
The snow is typically at its deepest on February 2, with a median depth of 5.0"; the depth exceeds 10.3" only one year out of ten.
The relative humidity typically ranges from 42% (comfortable) to 99% (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 April 20, at which time the relative humidity drops below 51% (mildly humid) three days out of four; it is most humid around August 6, exceeding 100% (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 2Â°F (dry) to 66Â°F (muggy) and is rarely below -21Â°F (dry) or above 72Â°F (very muggy).
There are two periods in the year that are most comfortable: The first is between May 18 and July 22 and the second is between August 1 and October 8. 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 15 mph (calm to moderate breeze), rarely exceeding 21 mph (fresh breeze).
The highest average wind speed of 8 mph (gentle breeze) occurs around April 14, at which time the average daily maximum wind speed is 14 mph (moderate breeze).
The lowest average wind speed of 5 mph (light breeze) occurs around August 9, at which time the average daily maximum wind speed is 11 mph (gentle breeze).