Published on Jun. 16, 2026, 11:44 AM
Updated on Jun. 16, 2026, 11:45 AM
A potential record-setting low pressure system is set to impact Ontario, with heavy rain, strong winds, and thunderstorms expected
Ontario is bracing for a potentially record-breaking low pressure system as a storm intensifies over the Great Lakes mid-week. Deep low pressure, possibly dropping to 990 mb or lower, could set a new record for the lowest June pressure on record.
Most regions are expected to receive 20-40 mm of rain through Thursday, with localized areas possibly exceeding 50 mm. The system’s rapid movement will help limit extreme rainfall amounts, however, the intensity and conditions will be more typical of a fall storm rather than a summer one.
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Tuesday: Thunderstorm chances with heavy rain and hail
A warm front will bring showers and thunderstorms to northeastern Ontario Tuesday. Isolated severe storms are possible, with threats of strong winds, hail over 2 cm, and heavy rainfall.
Pop-up afternoon showers are expected in inland areas of southern Ontario before instability builds in the evening.
Thunderstorms will spread across southwestern Ontario and along Lake Huron shores, moving inland and into the Greater Toronto Area (GTA) overnight.
Stronger storms near southern Georgian Bay and Lake Huron could bring heavy rain, strong winds, and small hail.
