April in Toronto is unpredictable – you can have anything from sunny and warm to major snow and ice storms. Usually, by May, the weather has stabilized a bit. But some years are exceptions.
On May 30, 1929, the Toronto Daily Star reported that Toronto was in the midst of a heat wave:
According to the weather records that I was able to look up, the high temperature for May 30, 1929 was 32.8C, or 91F. So the all-time record was not broken that day. The weather stayed warm for one more day, reaching 29.4C on May 31, but a cold front came through the next day, with the high temperature only reaching 15.6C.
May 26, 1961 went to the other extreme, as it had snowed the previous day, and there was a strong risk of frost that night:
This had actually been a rather sudden reversal, as the high temperature for May 25 was 26.1C. I’m not quite sure how it managed to snow on May 25, as the listed overnight low was 9.4C, but the records that I have indicate that yes, it did snow on that day. (It also rained a total of 19.6mm on that day, so I guess a system was blowing air in from the north.)
Gardeners in the Toronto district, at least, dodged a bullet, as the overnight low went down to 0.6C – close, but not right down to the freezing mark. (Outside of the city, farmers and gardeners might not have been so lucky.) The high temperature for that day was only 8.3C, but the temperature rebounded to seasonal shortly after. On May 28, the thermometer reached 24.4C.