Not as many records yesterday (Tuesday) as on the first 2 days of the heat event, but some cities. e.g. St. Catharines, had records broken all 3 days. Also, while today was not as hot, the humidex was still 37C mid-afternoon in most of the GTHA, not exactly a big “cool-down”.
Weather summary
for Ontario and the National Capital Region
issued by Environment Canada
at 10:55 a.m. EDT Wednesday 25 June 2025.
Discussion.
Southern Ontario saw multiple daily maximum temperature records with
an ongoing heat event.
The following areas set a daily maximum temperature record on June
24, 2025 (temperature values given in degrees Celsius):
BANCROFT AREA (Bancroft Auto)
New record of 32.2
Old record of 31.7 set in 2003
Records in this area have been kept since 1882
KEMPTVILLE AREA (Kemptville CS)
New record of 33.7
Old record of 32.8 set in 1907
Records in this area have been kept since 1902
KINGSTON AREA (Kingston Climate)
New record of 31.7
Old record of 30.6 set in 1919
Records in this area have been kept since 1872
NORFOLK AREA (Delhi CS)
New record of 35.8
Old record of 35.6 set in 1923
Records in this area have been kept since 1866
OSHAWA AREA (Oshawa)
New record of 35.4
Old record of 33.9 set in 1923
Records in this area have been kept since 1882
OTTAWA (RICHMOND - METCALFE) AREA (Ottawa Intl A)
New record of 34.3
Old record of 33.2 set in 2003
Records in this area have been kept since 1938
ST. CATHARINES AREA (Vineland Station RCS)
New record of 35.6
Old record of 35.0 set in 1923
Records in this area have been kept since 1901
TORONTO DOWNTOWN AREA (Toronto City)
New record of 36.5
Old record of 35.6 set in 1923
Records in this area have been kept since 1840
TRENTON AREA (Trenton A)
New record of 34.4
Old record of 31.7 set in 1966
Records in this area have been kept since 1921
