Yellow Watch - Severe Thunderstorm
3:47 p.m. EDT Tuesday 21 July 2026

Impact Level: Moderate

Forecast Confidence: High


Conditions are favourable for the development of severe thunderstorms that may be capable of producing strong wind gusts, large hail and heavy rain.

Hazards:
Torrential downpours. Local rainfall amounts in excess of 50 mm.
Wind gusts of 90 to 110 km/h.
Quarter size hail.

Timing:
Ending early this evening.

Additional information:
The main hazards will be heavy rainfall and damaging wind gusts. Local rainfall amounts in excess of 50 mm may occur for areas that receive multiple thunderstorms.

Local utility outages are possible. Damage to roofs, fences, branches or soft shelters is possible.

When thunder roars, go indoors! Lightning kills and injures Canadians every year.

Emergency Management Ontario recommends that you take cover immediately if threatening weather approaches.

Heavy rain can cause flash flooding and significant reductions to visibility.

Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on social media using #ONStorm.

For more information: https://www.ontario.ca/page/be-prepared-emergency.

In effect for:
  • London - Parkhill - Eastern Middlesex County

spacer
Updated: @ 21/07/2026 17:35 - next update at 17:40  
Summary / Temperature Wind Rain Outlook
Mostly cloudy Mostly cloudy
Currently: 22.7, Max: 29.2, Min: 19.9 22.7°C
Warmer 0.1°C than last hour.

Comfortable

Feels like: 23°C

24-hr difference
-2.2°CColder 2.2°C than yesterday at this time.
  Today Yesterday
High: 29.2°C
13:24
26.8°C
12:49
Low: 19.9°C
01:16
9.7°C
06:24
 Wind from N N
8
Gust:
23.5 km/h
2 Bft - Light breeze
Today: 40.7 km/h 14:14
Gust Month: 66.4 km/h July 1
Rain Today: 9.4 mm
Rain Rate (/hr): 0 mm
Rain Yesterday: 0 mm
This Month: 24 mm
Season Total: 427.4 mm
0 day since last rain.
Wed, 22 Jul
Chance of showers (60%)
Chance of showers
Humidity & Barometer Almanac Moon
Humidity: 77 % Decreased 3.0% since last hour.
Dew Point: 16.9°C Increased 0.4°C since last hour.
Barometer: 1001.4 hPa Rising 0.6  hPa/hr
Baro Trend: Rising
Sunrise: 06:04
Sunset: 20:59
Moonset: 00:03
Moonrise: 14:27
Waxing Gibbous
Waxing Gibbous, Moon at 7 days in cycle
54%
Illuminated
UV Index Solar Radiation
   1.0     Low 
High: 6.3 @ 13:10
281 W/m2
High: 1083 @  13:11
 EC Weather Forecast  - Outlook: Tonight & Wed, 22 Jul
Tonight
Chance of showers (40%)
Chance of showers

Min: 14°C
EC forecast: Cloudy with 40 percent chance of showers. Risk of a thunderstorm early this evening. Wind northwest 20 km/h becoming light this evening. Wind becoming northwest 30 gusting to 50 late this evening. Low 14.
Davis VP+ forecast: Not available
 
Wed, 22 Jul
Chance of showers (60%)
Chance of showers

Max: 23°C
EC forecast: A mix of sun and cloud with 60 percent chance of showers in the morning. Clearing late in the afternoon. Wind northwest 20 km/h gusting to 40. High 23. Humidex 25. UV index 7 or high.