Thursday will be mainly sunny across much of the region, with a mix of sun and cloud expected across portions of Central and Eastern Ontario. The UV Index is expected to be in the Very High category across the area tomorrow. UV Index values of 8 and 9 are forecasted.

**Very High UV Index Wednesday** With mainly sunny skies expected Wednesday, the UV Index is forecasted to be in the Very High category across the region. All areas are forecasted to see a UV Index of 8.

Wednesday will bring mainly sunny skies with dry conditions once again. Humidity will remain low across the region. High UV Index is forecasted across the region tomorrow, with all areas forecasted a UV Index of 8.

**Very High UV Index Monday** With mainly sunny skies expected across much of the region on Monday, the UV Index is forecasted to be in the High to Very High categories. The highest UV Index is expected to be 9 in Windsor (Very High).

Welcome to June! Mainly sunny skies are expected across much of the area for Monday, however Central and Eastern Ontario are expected to see a mix of sun and cloud. A few sprinkles are possible, but the chances are fairly low.

**Very High UV Index Sunday** With mainly sunny skies expected across the region for Sunday, the UV Index is forecasted to be in the High to Very High categories.

Sunday will bring some showers and cloudy skies to portions Central and Eastern Ontario, while the rest of the region sees mainly sunny skies. There is a low risk for a thunderstorm in Central and Eastern Ontario during the afternoon hours tomorrow.

**Very High UV Index Saturday** With mainly sunny skies expected across the region for Saturday, the UV Index is forecasted to be in the High to Very High categories.

**3 Tornadoes and 1 Downburst Confirmed on Tuesday, May 19, 2026** On May 19, 2026, severe thunderstorms passed through Southwestern Ontario during the afternoon and evening hours.

Saturday will be a slightly cooler day across the region, however the quiet period of weather will continue with mainly sunny skies forecasted. The UV Index is forecasted to be in the High to Very High category in many areas tomorrow.

**Very High UV Index Friday** With mainly sunny skies expected across the region for Thursday, the UV Index is forecasted to be in the High to Very High categories. The highest UV Index is expected to be 9 (Very High), which will be in Windsor and Chatham.

Friday will be a pretty warm day in Southwestern Ontario, however rain showers are in the forecast for Central and Eastern Ontario. Rain showers are likely to move into Central and Eastern Ontario during the morning hours and will linger through the day.

**Very High UV Index Thursday** With mainly sunny skies expected across the region for Tuesday, the UV Index is forecasted to be in the Moderate to Very High categories. The highest UV Index is expected to be 8 (Very High), which will be in Windsor and Chatham.

Thursday will be a cooler day across the region, with mainly sunny skies expected. Temperatures will be in the mid to upper teens. No precipitation is forecasted tomorrow, however some wind gusts up to 40 km/h will be possible at times, mainly in Southwestern Ontario.

Wednesday will bring a mix of sun and cloud across the area, as well as warm conditions with many areas in the low to mid 20s. The UV Index is forecasted to be in the Very High category for many areas tomorrow.

**Very High UV Index Tuesday** With mainly sunny skies expected across the region for Tuesday, the UV Index is forecasted to be in the High and Very High categories. The highest UV Index is expected to be 9, which will be in Windsor and Chatham.

Tuesday will bring mainly sunny skies to most of the region, with. mix of sun and clouds in Southwestern Ontario. it will be slightly humid with Humidex values in the mid 20s to low 30s.

Monday will bring decreasing clouds during the morning and early afternoon, leading to mainly sunny skies. It will also be a warmer day across the area. Fog is likely to develop overnight into the morning hours.

Some showers will remain around Central and Eastern Ontario through the day on Sunday, with mainly cloudy skies expected elsewhere. Some peeks of sunshine are expected in Southwestern Ontario.

9:46 AM ET - Special Weather Statements are now in effect for many areas along the Lake Erie and Lake Ontario shorelines. Rainfall amounts of 30 to 50 mm are possible today and tonight.

Saturday will be a wet and windy day across the region. Rain will begin moving into Southwestern Ontario during the early morning hours and will move from west to east. Rain is expected to arrive in Eastern Ontario by the late afternoon or early evening hours.

6:12 PM ET - Special Weather Statement in effect for Chatham-Kent and Windsor-Essex. Rainfall with amounts of 30 to 50 mm are possible overnight through Saturday evening.

**Wet and Windy Conditions Saturday** Rain will begin moving into Southwestern Ontario during the early morning hours on Saturday, moving from west to east. Rain will arrive in Eastern Ontario by the late afternoon or early evening hours.

Friday will bring sun and clouds to the region, along with temperatures slightly warmer than today once again. As temperatures fall to near the freezing mark overnight into tomorrow morning, frost is expected over much of Central and Eastern Ontario.

**Frost Expected Thursday Night into Friday Morning** As temperatures are expected to fall below the freezing mark in Central and Eastern Ontario Thursday night into Friday morning, frost is expected.

The NTP team surveying the London-area damage completed the survey in east London yesterday evening. We are now able to confirm that the damage in east London was caused by an EF1 downburst - with winds to 145 km/h. Full details for all of the London-area events will be provided asap. #ONstorm

**Very High UV Index Thursday** With mainly sunny skies expected across the region for Thursday, the UV Index is forecasted to be in the High and Very High categories. The highest UV Index is expected to be 9, which will be in Windsor and Chatham.

Thursday will be a slightly warmer day across the area with mainly sunny skies throughout the day. Precipitation is not forecasted. With the sunny conditions expected tomorrow, the UV Index is forecasted to be in the Very High category for many areas.

The Northern Tornadoes Project confirms that a tornado did occur yesterday just southeast of London, ON, at Derwent. Video, radar and a preliminary investigation done last evening provided the necessary evidence. An NTP survey team will still visit the area to determine intensity and track. #ONstorm

**UPDATE: Frost Expected Wednesday Night** Frost Advisories have now been issued by Environment Canada. Temperatures will fall near or below 0ºC across portions of Central, Eastern and Midwestern Ontario tonight into early Thursday morning.

**Frost Possible Wednesday Night** Temperatures will fall near or below 0ºC across portions of Central, Eastern and Midwestern Ontario tonight into early Thursday morning. With the right conditions present, frost may occur.

**Very High UV Index Wednesday** With a mix of sun and cloud expected across the region for Wednesday, the UV Index is forecasted to be in the High and Very High categories. Ultraviolet (UV) rays can cause sunburns, skin cancer and eye cataracts.

Wednesday will be a much cooler day across the region, along with a mix of sun and clouds. Some isolated showers will be possible. Due to the severe weather with destructive winds that passed through the area this evening, clean up will be ongoing through the day tomorrow.

May 19, 2026 - STORM REPORTS: We are looking for storm reports and photos of the severe weather that went through the region today. Please include a location and all relevant details for any report.

8:16 PM ET - Here are the latest weather alerts in effect. Severe Thunderstorm Watches have been issued for Eastern #Ontario but have ended for the GTHA. All alerts are now Yellow Level.

7:38 PM ET - ALL Tornado Warnings have ENDED. The Red Severe Thunderstorm Warning is now ORANGE level. THUNDERSTORM LOCATION: GRASSIE TO JAMES N. ALLAN PROVINCIAL PARK MOTION: MOVING QUICKLY TO THE EAST AT 90 KM/H HAZARDS: WIND: DAMAGING (110 - 129 KM/H) RISK OF TORNADO

7:09 PM ET - RED LEVEL Severe Thunderstorm Warning for City of #Hamilton, St. Catharines - Grimsby - Northern Niagara Region, Niagara Falls - Welland - Southern Niagara Region and Dunnville - Caledonia - Haldimand. THUNDERSTORM LOCATION: MOUNT HOPE TO JARVIS

6:59 PM ET - TORNADO WARNING issued for Fenelon Falls - Balsam Lake Park - Northern Kawartha Lakes and Apsley - Woodview - Northern Peterborough County. TORNADO LOCATION: NEAR ALPINE VILLAGE MOTION: MOVING QUICKLY TO THE EAST AT 65 KM/H HAZARDS: TORNADO

6:37 PM ET - TORNADO WARNING in effect for Oxford - Brant and Simcoe - Delhi - Norfolk. FIRST TORNADO LOCATION: OVER BURGESSVILLE SECOND TORNADO LOCATION: SPRINGFORD MOTION: MOVING QUICKLY TO THE EAST AT 80 KM/H HAZARDS: TORNADO WIND: DAMAGING (110 - 130 KM/H)

6:26 PM ET - TORNADO WARNING for Brantford - County of Brant and Woodstock - Tillsonburg - Oxford County. TORNADO LOCATION: WOODSTOCK TO OSTRANDER MOTION: MOVING EAST AT 65 KM/H HAZARDS: TORNADO WIND: DAMAGING (90 - 110 KM/H) HAIL: UP TO QUARTER SIZE (UP TO 2.5 CM)

6:14 PM ET - TORNADO WARNING in effect for Woodstock - Tillsonburg - Oxford County, St. Thomas - Aylmer - Eastern Elgin County, London - Parkhill - Eastern Middlesex County. FIRST TORNADO LOCATION: OVER DORCHESTER SECOND TORNADO LOCATION: OVER BELMONT

5:46 PM ET - TORNADO WARNING now issued for London - Parkhill - Eastern Middlesex County. TORNADO LOCATION: OVER MOUNT BRYDGES MOTION: MOVING QUICKLY TO THE EAST AT 60 KM/H HAZARDS: TORNADO WIND: DAMAGING (90 - 110 KM/H) HAIL: UP TO QUARTER SIZE (UP TO 2.5 CM)

5:26 PM ET - TORNADO WARNING issued for Strathroy - Komoka - Western Middlesex County. TORNADO LOCATION: OVER ALVINSTON MOTION: MOVING EAST AT 50 KM/H HAZARDS: TORNADO WIND: DAMAGING (90 - 110 KM/H) HAIL: UP TO QUARTER SIZE (UP TO 2.5 CM)

5:12 PM ET - Here are the current weather alerts in effect. Severe Thunderstorm Watches have now expanded, including #Hamilton and #Toronto. Environment Canada continues to state that hazards include: Winds gusting 90 to 110 km/h. Hail up to quarter sized.

4:57 PM ET - Severe Thunderstorm Warning in effect for Fenelon Falls - Balsam Lake Park - Northern Kawartha Lakes, Apsley - Woodview - Northern Peterborough County, and Haliburton. Thunderstorm Location: Eagle Lake to Lutterworth to Coboconk Motion: Moving east at 60 km/h

4:34 PM ET - Here is an update on the current Severe Thunderstorm Warnings. Hazards: Wind: damaging (90 - 110 km/h) Hail: up to quarter size (up to 2.5 cm) #ONwx

4:18 PM ET - Severe Thunderstorm Warning issued for Goderich - Bluewater - Southern Huron County. Thunderstorm Location: About 20 km west of Ipperwash Beach Motion: Moving quickly to the northeast at 65 km/h Hazard: Wind - Damaging (90-110 km/h)

3:36 PM ET - Severe Thunderstorm Warning now includes Watford - Pinery Park - Eastern Lambton County. Thunderstorm Location: 15 km west of Corunna Motion: Moving quickly to the east at 65 km/h Hazards: Wind: damaging (90 - 110 km/h) Hail: up to quarter size (up to 2.5 cm)

3:04 PM ET - RADAR UPDATE: We are currently monitoring these thunderstorms in Michigan that are under Severe Thunderstorm Warnings. A Severe Thunderstorm Warning remains in effect for Sarnia - Petrolia - Western Lambton County at this time.

2:51 PM ET - Severe Thunderstorm Warning issued for Sarnia - Petrolia - Western Lambton County. A severe thunderstorm was located 45 km northwest of Windsor, moving east at 70 km/h. Hazards: 100 km/h wind gusts and quarter size hail.