Residents of St. Thomas can expect an unsettled week of weather as a mix of clouds and rain continues through Monday, May 11, 2026. While conditions remain damp and cool, Environment Canada reports that there is currently a rainfall warning in effect for Eastern Elgin County, which includes the St. Thomas area.
Today, Tuesday, May 5, will be mainly cloudy with showers beginning near noon. Residents should prepare for gusty conditions, with southwest winds blowing at 30 km/h and reaching gusts of up to 50 km/h before shifting to a 20 km/h northwest wind this afternoon. The high is expected to reach 16°C, with rain continuing into the evening hours when temperatures drop to a low of 7°C.
The week ahead remains cooler than the seasonal norm of 17°C, with daily highs fluctuating between 11°C and 16°C. Wednesday will see a few lingering showers end by late morning, followed by a brief period of sunny skies on Thursday. The highest probability of rain during the week occurs this Friday, with a 60 percent chance of showers and a high of 11°C. The weekend will bring a mix of sun and cloud on Saturday, with conditions clearing to mainly sunny weather by Sunday and Monday.
These current conditions align with broader seasonal trends for the region. Long-range outlooks, including reports from The Old Farmer’s Almanac, The Weather Network, and Harrowsmith Magazine, have anticipated an active and wetter-than-normal spring season for Southern Ontario, often characterized by frequent precipitation and temperatures slightly below historical averages.