Summer Weather in Toronto Canada
Daily high temperatures increase by 6°F, from 68°F to 74°F, rarely falling below 59°F or exceeding 85°F. The highest daily average high temperature is 78°F on July 25.
Daily low temperatures increase by 7°F, from 53°F to 60°F, rarely falling below 45°F or exceeding 70°F. The highest daily average low temperature is 63°F on July 31.
For reference, on July 20, the hottest day of the year, temperatures in Toronto typically range from 63°F to 78°F, while on January 29, the coldest day of the year, they range from 17°F to 29°F.
Average High and Low Temperature in the Summer in Toronto
The figure below shows you a compact characterization of the hourly average summer temperatures. The horizontal axis is the day, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature in the Summer in Toronto
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
The summer in Toronto experiences rapidly decreasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy decreasing from 47% to 34%. The lowest chance of overcast or mostly cloudy conditions is 33% on August 20.
The clearest day of the summer is August 20, with clear, mostly clear, or partly cloudy conditions 67% of the time.
For reference, on January 10, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 61%, while on August 20, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 67%.
Cloud Cover Categories in the Summer in Toronto
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Toronto, the chance of a wet day over the course of the summer is essentially constant, remaining around 28% throughout.
For reference, the year's highest daily chance of a wet day is 31% on June 14, and its lowest chance is 14% on January 31.
Probability of Precipitation in the Summer in Toronto
To show variation within the season and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day.
The average sliding 31-day rainfall during the summer in Toronto is essentially constant, remaining about 1.9 inches throughout, and rarely exceeding 3.4 inches or falling below 0.7 inches.
Average Monthly Rainfall in the Summer in Toronto
Over the course of the summer in Toronto, the length of the day is rapidly decreasing. From the start to the end of the season, the length of the day decreases by 1 hour, 58 minutes, implying an average daily decrease of 1 minute, 18 seconds, and weekly decrease of 9 minutes, 5 seconds.
The shortest day of the summer is August 31, with 13 hours, 15 minutes of daylight and the longest day is June 21, with 15 hours, 27 minutes of daylight.
Hours of Daylight and Twilight in the Summer in Toronto
The earliest sunrise of the summer in Toronto is 5:35 AM on June 15 and the latest sunrise is 1 hour, 5 minutes later at 6:39 AM on August 31.
The latest sunset is 9:03 PM on June 27 and the earliest sunset is 1 hour, 8 minutes earlier at 7:55 PM on August 31.
Daylight saving time is observed in Toronto during 2023, but it neither starts nor ends during the summer, so the entire season is in daylight saving time.
For reference, on June 21, the longest day of the year, the Sun rises at 5:35 AM and sets 15 hours, 27 minutes later, at 9:02 PM, while on December 22, the shortest day of the year, it rises at 7:48 AM and sets 8 hours, 55 minutes later, at 4:43 PM.
Sunrise & Sunset with Twilight in the Summer in Toronto
The figure below presents a compact representation of the sun's elevation (the angle of the sun above the horizon) and azimuth (its compass bearing) for every hour of every day in the reporting period. The horizontal axis is the day of the year and the vertical axis is the hour of the day. For a given day and hour of that day, the background color indicates the azimuth of the sun at that moment. The black isolines are contours of constant solar elevation.
Solar Elevation and Azimuth in the Summer in Toronto
The figure below presents a compact representation of key lunar data for the summer of 2023. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases. The label associated with each bar indicates the date and time that the phase is obtained, and the companion time labels indicate the rise and set times of the Moon for the nearest time interval in which the moon is above the horizon.
Moon Rise, Set & Phases in the Summer in Toronto
We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.
The chance that a given day will be muggy in Toronto is rapidly increasing during the summer, rising from 2% to 17% over the course of the season.
The highest chance of a muggy day during the summer is 26% on August 1.
For reference, on August 1, the muggiest day of the year, there are muggy conditions 26% of the time, while on October 25, the least muggy day of the year, there are muggy conditions 0% of the time.
Humidity Comfort Levels in the Summer in Toronto
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.
The average hourly wind speed in Toronto is essentially constant during the summer, remaining within 0.4 miles per hour of 8.8 miles per hour throughout.
For reference, on January 12, the windiest day of the year, the daily average wind speed is 14.4 miles per hour, while on August 4, the calmest day of the year, the daily average wind speed is 8.4 miles per hour.
The lowest daily average wind speed during the summer is 8.4 miles per hour on August 4.
Average Wind Speed in the Summer in Toronto
The hourly average wind direction in Toronto throughout the summer is predominantly from the west, with a peak proportion of 45% on July 9.
Wind Direction in the Summer in Toronto
Toronto is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.
The average surface water temperature in Toronto is very rapidly increasing during the summer, rising by 19°F, from 49°F to 68°F, over the course of the season.
The highest average surface water temperature during the summer is 69°F on August 12.
Average Water Temperature in the Summer in Toronto
Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).
The growing season in Toronto typically lasts for 6.2 months (189 days), from around April 20 to around October 26, rarely starting before April 3 or after May 7, and rarely ending before October 4 or after November 14.
The summer in Toronto is reliably fully within the growing season.
Time Spent in Various Temperature Bands and the Growing Season in the Summer in Toronto
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.
The average accumulated growing degree days in Toronto are very rapidly increasing during the summer, increasing by 1,611°F, from 256°F to 1,867°F, over the course of the season.
Growing Degree Days in the Summer in Toronto
This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.
The average daily incident shortwave solar energy in Toronto is decreasing during the summer, falling by 1.2 kWh, from 6.6 kWh to 5.4 kWh, over the course of the season.
The highest average daily incident shortwave solar energy during the summer is 7.0 kWh on June 30.
Average Daily Incident Shortwave Solar Energy in the Summer in Toronto
For the purposes of this report, the geographical coordinates of Toronto are 43.700 deg latitude, -79.416 deg longitude, and 561 ft elevation.
The topography within 2 miles of Toronto contains only modest variations in elevation, with a maximum elevation change of 262 feet and an average elevation above sea level of 524 feet. Within 10 miles contains only modest variations in elevation (525 feet). Within 50 miles contains significant variations in elevation (1,483 feet).
The area within 2 miles of Toronto is covered by artificial surfaces (97%), within 10 miles by artificial surfaces (58%) and water (23%), and within 50 miles by water (30%) and cropland (25%).
This report illustrates the typical weather in Toronto, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
There are 3 weather stations near enough to contribute to our estimation of the temperature and dew point in Toronto.
For each station, the records are corrected for the elevation difference between that station and Toronto according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
The estimated value at Toronto is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Toronto and a given station.
The stations contributing to this reconstruction are:
To get a sense of how much these sources agree with each other, you can view a comparison of Toronto and the stations that contribute to our estimates of its temperature history and climate. Please note that each source's contribution is adjusted for elevation and the relative change present in the MERRA-2 data.
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Algorithms 2nd Edition , by Jean Meeus.
All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.
Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.
Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.
Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .
Time zones for airports and weather stations are provided by AskGeo.com .
Maps are © OpenStreetMap contributors.
The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data is prone to errors, outages, and other defects. We assume no responsibility for any decisions made on the basis of the content presented on this site.
We draw particular cautious attention to our reliance on the MERRA-2 model-based reconstructions for a number of important data series. While having the tremendous advantages of temporal and spatial completeness, these reconstructions: (1) are based on computer models that may have model-based errors, (2) are coarsely sampled on a 50 km grid and are therefore unable to reconstruct the local variations of many microclimates, and (3) have particular difficulty with the weather in some coastal areas, especially small islands.
We further caution that our travel scores are only as good as the data that underpin them, that weather conditions at any given location and time are unpredictable and variable, and that the definition of the scores reflects a particular set of preferences that may not agree with those of any particular reader.
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