For comparison, the temperature distribution for each date of the year is presented below.

Based on 455,742 weather observations recorded by Statistics Canada between January 1953 and May 2025, temperatures in Toronto ranged from –27.5°C to 37.4°C — a total spread of 64.9°C. The lowest temperature, –27.5°C, was recorded between 7 and 8 a.m. on January 4, 1981, while the highest, 37.4°C, occurred at 3 p.m. on July 21, 2011.

The average yearly mean and median temperatures are nearly identical, at 9.38°C and 9.4°C, respectively.

In an average year, the temperature range spread is 18% (or 11.8 °C) smaller, totaling 53.1 °C, with temperatures ranging from –20.1 °C to 33.1 °C. The average interquartile range IQR is 16.3°C (18°C – 1.7°C) and average calculated whiskers are -22.75°C (1.7°C – 16.3°C*1.5) and 42.45°C (18°C+16.3°C*1.5). However, the actual average whiskers are –19.63 °C and 33.08 °C. Any temperature values outside this range may be considered outliers.

The lowest median temperature of 7.2°C was observed in the years 1972, 1974, 1976, 1996, and 1997. The coldest year overall was 1976, with the lowest average temperature of 7.11°C. In contrast, the hottest year was 1961, which recorded both the highest median temperature of 13.3°C and the highest average temperature of 12.08°C.

Below is the temperature distribution by year starting from 1953.

The coldest month on record was February 2015, with an average temperature of –10.8 °C. The hottest month was July 2020, which had an average temperature of 25.12 °C.

The most commonly reported temperature in Toronto is approximately 2°C, occurring in about 4% of all observations. This percentage translates to roughly 1,000 days in total, or about 14 days per year. The most frequent temperatures by season are: 6°C in spring, 22°C in summer, 8°C in autumn, and 2°C in winter.

The bar charts below visualize the annual and seasonal average temperatures measured at two times of day—7:00 AM (blue bars) and 1:00 PM (orange bars)—from 1953 to 2024, each with corresponding linear trendlines in blue and orange. The graphs illustrate long-term temperature trends in Toronto.

All trend lines show an upward slope, indicating a gradual warming trend over the decades. The 7:00 AM temperature increases at about 0.03°C per year, with an R² of 0.4214, suggesting a moderate correlation. The 1:00 PM temperature rises at a slower rate of about 0.02°C per year, with a lower R² of 0.1229. These relatively low R² values mean that, although the overall trend is upward, there is considerable year-to-year variability. This variation may be due to natural climate fluctuations or extreme weather events. The rise in both morning and afternoon temperatures points to the influence of long-term climate change in the region. Morning temperatures appear to be increasing slightly faster than afternoon ones, possibly because nighttime heat is being retained more effectively—perhaps due to the urban heat island effect or broader atmospheric warming.

Data sources:
     OpenWeather,
     Environment and Climate Change Canada
          Jan 1953 – May 1969 Station Name: TORONTO (Longitude -79.4, Latitude 43.67),
          Jun 1969 – May 2002 Station Name: TORONTO ISLAND A (Longitude -79.4, Latitude 43.63),
          Jun 2002 – May 2025 Station Name: TORONTO CITY (Longitude -79.4, Latitude 43.67).

Tools used:
     a combination of R for data unification, transformation, and visualization,
     Microsoft Excel — including formulas, PivotTables, and PivotCharts — for data analysis and additional visualization.