Location
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%).
Temperature
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.
Daily High and Low Temperature
The daily average low (blue) and high (red) temperature with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).
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.
Fraction of Time Spent in Various Temperature Bands
The average fraction of time spent in various temperature bands: frigid (below -9°C), freezing (-9°C to 0°C), cold (0°C to 10°C), cool (10°C to 18°C), comfortable (18°C to 24°C), warm (24°C to 29°C), hot (29°C to 38°C) and sweltering (above 38°C).
Sun
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.
Daily Hours of Daylight and Twilight
The number of hours during which the Sun is visible (black line), with various degrees of daylight, twilight, and night, indicated by the color bands. From bottom (most yellow) to top (most gray): full daylight, solar twilight (Sun is visible but less than 6° from the horizon), civil twilight (Sun is not visible but is less than 6° below the horizon), nautical twilight (Sun is between 6° and 12° below the horizon), astronomical twilight (Sun is between 12° and 18° below the horizon), and full night.
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.
Daily Sunrise & Sunset with Twilight and Daylight Savings Time
The solar day over the course of the year 2012 . From bottom to top, the black lines are the previous solar midnight, sunrise, solar noon, sunset, and the next solar midnight. The day, twilights (solar, civil, nautical, and astronomical), and night are indicated by the color bands from yellow to gray. The transitions to and from daylight savings time are indicated by the "DST" labels.
Clouds
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.
Median Cloud Cover
The median daily cloud cover (black line) with percentile bands (inner band from 40th to 60th percentile, outer band from 25th to 75th percentile).
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.
Cloud Cover Types
The fraction of time spent in each of the five sky cover categories. From top (most blue) to bottom (most gray), the categories are clear, mostly clear, partly cloudy, mostly cloudy, and overcast. Pink indicates missing data. Outside of the United States clear skies are often reported ambiguously, leading them to be lumped in with the missing data.
Precipitation
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.
Probability of Precipitation at Some Point in the Day
The fraction of days in which various types of precipitation are observed. If more than one type of precipitation is reported in a given day, the more severe precipitation is counted. For example, if light rain is observed in the same day as a thunderstorm, that day counts towards the thunderstorm totals. The order of severity is from the top down in this graph, with the most severe at the bottom.
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.
Types of Precipitation Throughout the Year
Relative frequency of various types of precipitation over the course of a typical year.
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%).
Warm Season Precipitation
Cold Season Precipitation
Relative frequency of various types of precipitation during the warm and cold seasons respectively.
Snow
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.
Probability of Snow Fall Being Reported in a Given Day
Probability that snow will be reported at least once in a given day. The season is defined as the period during which the probability is greater than one third the maximum probability.
Either snow rarely accumulates at this location or snow depth measurements are unavailable or unreliable.
Humidity
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.
Relative Humidity
The average daily high (blue) and low (brown) relative humidity with percentile bands (inner bands from 25th to 75th percentile, outer bands from 10th to 90th percentile).
Dew Point
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.
Dew Point
The daily average low (blue) and high (red) dew point with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).
Wind
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).
Wind Speed
The average daily minimum (red), maximum (green), and average (black) wind speed with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).
Wind Directions Over the Entire Year
The fraction of time spent with the wind blowing from the various directions over the entire year. Values do not sum to 100% because the wind direction is undefined when the wind speed is zero.
Fraction of Time Spent with Various Wind Directions
The fraction of time spent with the wind blowing from the various directions on a daily basis. Stacked values do not always sum to 100% because the wind direction is undefined when the wind speed is zero.