This report describes the typical weather at the Billy Bishop Toronto City Airport (Toronto, Ontario, Canada) weather station over the course of an average year. It is based on the historical records from 1980 to 2012. Earlier records are either unavailable or unreliable.
Toronto, Ontario has a humid continental climate with warm summers and no dry season. The area within 40 km of this station is covered by oceans and seas (48%), grasslands (39%), built-up areas (9%), and forests (5%).
Over the course of a year, the temperature typically varies from -7°C to 25°C and is rarely below -15°C or above 29°C.
The warm season lasts from June 4 to September 18 with an average daily high temperature above 20°C. The hottest day of the year is July 26, with an average high of 25°C and low of 18°C.
The cold season lasts from December 2 to March 18 with an average daily high temperature below 4°C. The coldest day of the year is January 18, with an average low of -7°C and high of -1°C.
The length of the day varies significantly over the course of the year. The shortest day is December 21 with 8:55 hours of daylight; the longest day is June 20 with 15:25 hours of daylight.
The earliest sunrise is at 5:35am on June 13 and the latest sunset is at 9:04pm on June 28. The latest sunrise is at 7:57am on November 3 and the earliest sunset is at 4:40pm on December 9.
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 23% (mostly clear) to 92% (mostly cloudy). The sky is cloudiest on December 26 and clearest on August 7. The clearer part of the year begins around March 30. The cloudier part of the year begins around October 19.
On August 7, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 52% of the time, and overcast or mostly cloudy 28% of the time.
On December 26, the cloudiest day of the year, the sky is overcast, mostly cloudy, or partly cloudy 58% of the time, and clear or mostly clear 24% of the time.
The probability that precipitation will be observed at this location varies throughout the year. Precipitation is most likely around December 27, occurring in 71% of days. Precipitation is least likely around August 26, occurring in 42% 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 35% of those days with precipitation. It is most likely around October 21, when it is observed during 27% of all days.
Light snow is the most severe precipitation observed during 29% of those days with precipitation. It is most likely around February 1, when it is observed during 47% of all days.
Moderate rain is the most severe precipitation observed during 18% of those days with precipitation. It is most likely around October 8, when it is observed during 13% of all days.
During the warm season, which lasts from June 4 to September 18, there is a 44% 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 (50% of days with precipitation have at worst light rain), moderate rain (20%), thunderstorms (17%), and heavy rain (9%).
During the cold season, which lasts from December 2 to March 18, there is a 66% 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), light rain (15%), moderate rain (11%), and moderate snow (7%).
The likelihood of snow falling is highest around January 28, occurring in 54% of days. The season in which it is relatively likely for snow to fall spans from November 13 to April 8.
Either snow rarely accumulates at this location or snow depth measurements are unavailable or unreliable.
The relative humidity typically ranges from 49% (comfortable) to 89% (very humid) over the course of the year, rarely dropping below 29% (dry) and reaching as high as 100% (very humid).
The air is driest around April 27, at which time the relative humidity drops below 61% (mildly humid) three days out of four; it is most humid around October 5, exceeding 84% (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 -12°C (dry) to 19°C (muggy) and is rarely below -22°C (dry) or above 22°C (very muggy).
There are two periods in the year that are most comfortable: The first is between May 20 and July 23 and the second is between August 13 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 m/s to 9 m/s (light air to fresh breeze), rarely exceeding 14 m/s (high wind).
The highest average wind speed of 6 m/s (moderate breeze) occurs around January 12, at which time the average daily maximum wind speed is 9 m/s (fresh breeze).
The lowest average wind speed of 3 m/s (light breeze) occurs around July 25, at which time the average daily maximum wind speed is 6 m/s (moderate breeze).