Historical May Precipitation Records
With rain in the forecast, it is a great opportunity to explore the May precipitation records in Toronto. Based on Toronto Pearson’s 71 years of weather records, here are the extremes:
24-hour precipitation record: 92.7 mm (May 31, 1944)
24-hour snowfall record: 2.3 cm (May 7, 1976) and trace of snow on the ground
Wettest May: 208.6 mm (1942)
Driest May: 9.4 mm (1949)
Four of the 20 wettest days in the history of CYYZ (>50 mm) occurred in the month of May:
May 15, 1942 - 50.3 mm
May 31, 1944 - 92.7 mm
May 16, 1974 - 53.1 mm
May 12, 2000 - 53.8 mm
The wettest May endured five major weather systems with the most intense one occurred during the last three days of the month in 1942. The three day rainfall total was 60.4 mm where 58.9 mm fell in just two days! Although the center of the low was in the Minnesota and Iowa border, the warm front extended up to Eastern New York. With strong southerly winds and humid conditions, it felt like mid-summer than late spring. Maximum temperature peaked at 30.0 deg. C and the mean was a mild 22.5 deg. C.
Below is the weather map forecast produced by the U.S. Department of Commerce Weather Bureau on May 31st, 1942.
The weather map was produced from the Washington, D.C. weather bureau and forecasts can be obtained using automated phone messages. Note, however, that the forecast map was not released full 7 days after it was created. Imagine Environment Canada releasing weather “forecast” maps for what happened last week.
