June saw record-breaking heat and unusually cool temperatures in Waterloo region

Waterloo region saw an erratic start to summer this year with both record-breaking heat and unusually cool temperatures in June.

According to the University of Waterloo's E.D. Soulis Weather Station, last month was the sixth hottest June on record.

The hottest day came on June 24, when temperatures jumped to a scorching 35 C, marking the third highest reading the station has seen in its 25-plus year history. In total, last month had five days over 30 C. This is above the average of just three days.

But it wasn't only punishing heat that hit the region in June. June 2 saw temperatures dip to 2.4 C, marking the coldest June temperature since 1998.

June also saw a few dry spells with very few wet days. The region received 86 mm of rain, which is higher than the long-term average of 70.1 mm, however, it is still within the average range for June.

Looking ahead to July, Alexandra Cournoyer, spokesperson for Environment and Climate Change Canada, says the region will see more average temperatures as the month goes on.

"Up to July 6, we should see some above-normal temperatures during that period of time by two to three degrees. However, for the rest of July so far the temperatures looks close to normal," she said. 

Cournoyer added that even if there are a few hotter than normal days, she believes the overall temperature will remain normal. 

"We can have a couple of days that are warmer followed by a couple of days that are colder. When everything is put together the main temperature becomes near normal to normal," she said.

June 2025 summary: 

• Maximum temperature was 35 C.
• Minimum temperature was 2.4 C.
• Average daily high temperature was 27 C (Long-term average is 24.1 C).
• Average daily low temperature was 13.8 C (Long-term average is 12.6 C).
• Total precipitation was 86 mm (Long-term average is 70.1 mm).