Residents in Cornwall, Ontario, should prepare for a significant weather shift on March 16, 2026, as temperatures are expected to hit 16°C before dropping below freezing tonight. Environment Canada reports that this unseasonably warm weather is well above the normal high of 3°C for this time of year.
The forecast includes a risk of thunderstorms and heavy rain throughout the day, with totals between 10 and 20 millimetres. This sudden warmth and rain could create drainage problems for homeowners and local businesses as the ground handles the moisture.
By midnight, the weather will change quickly with rain turning into snow and blowing snow. The community can expect about 2 to 4 centimetres of snowfall as the temperature plunges to an overnight low of -6°C, which is closer to the typical seasonal low of -7°C.
Forecasters are also warning of a risk of freezing rain after midnight. This rapid freeze could make roads and sidewalks very slippery for anyone travelling on Tuesday morning.
