Live Weather & Forecast
Weather in Sarnia
Ontario, Canada · Real-time conditions & 3-day outlook
8°C
Feels like 6°C
47°F / Feels 43°F
Mist
Sarnia, Ontario
🌞 Daytime
Updated: 2026-04-25 07:15
Humidity
93%
Wind
10.1 km/h E
Wind Gust
15.5 km/h
Pressure
1009 mb
Visibility
8 km
UV Index
0
(Low)
Precipitation
0.03 mm
Cloud Cover
100%
Dew Point
8.6°C
Wind Degree
86°
Air Quality Index
US EPA: Good
UK DEFRA: Low (1)
CO
177.9 μg/m³
NO₂
10.3 μg/m³
O₃
67 μg/m³
SO₂
3 μg/m³
PM 2.5
10.1 μg/m³
PM 10
10.9 μg/m³
Today's Hourly Forecast
24-hour breakdown for Sarnia, Ontario
12 AM
11°
Patchy light drizzle
1 AM
10°
Light drizzle
2 AM
10°
Light drizzle
3 AM
10°
Light drizzle
4 AM
10°
Patchy rain nearby
5 AM
10°
Mist
6 AM
9°
Mist
7 AM
8°
Mist
8 AM
9°
Mist
9 AM
9°
Fog
10 AM
9°
Fog
11 AM
9°
Mist
12 PM
8°
Patchy rain nearby
1 PM
8°
Overcast
2 PM
8°
Overcast
3 PM
8°
Overcast
4 PM
9°
Overcast
5 PM
9°
Partly Cloudy
6 PM
8°
Partly Cloudy
7 PM
7°
Partly Cloudy
8 PM
7°
Sunny
9 PM
6°
Clear
10 PM
6°
Clear
11 PM
6°
Clear
3-Day Forecast
Daily overview for Sarnia, Ontario
Today
Patchy rain nearby
10°
/
5°
🌧️ 89% chance of rain
💧 Avg. humidity: 91%
💨 Max wind: 21.6 km/h
🌧️ Total precip: 1.85 mm
☀️ UV Index: 5.2
🌅 Sunrise: 06:32 AM
🌇 Sunset: 08:23 PM
🌙 Waxing Gibbous
🌑 Moon: 60% lit
Sun, Apr 26
Sunny
12°
/
5°
🌧️ 0% chance of rain
💧 Avg. humidity: 81%
💨 Max wind: 18 km/h
🌧️ Total precip: 0 mm
☀️ UV Index: 6
🌅 Sunrise: 06:30 AM
🌇 Sunset: 08:25 PM
🌙 Waxing Gibbous
🌑 Moon: 70% lit
Mon, Apr 27
Sunny
17°
/
7°
🌧️ 0% chance of rain
💧 Avg. humidity: 72%
💨 Max wind: 38.9 km/h
🌧️ Total precip: 0.03 mm
☀️ UV Index: 6.6
🌅 Sunrise: 06:29 AM
🌇 Sunset: 08:26 PM
🌙 Waxing Gibbous
🌑 Moon: 79% lit
Best Time to Visit Sarnia
Plan your trip to Sarnia, Canada around the most favorable weather conditions.
Peak Season
June – September
Warm, dry summers — ideal for outdoor activities.
Shoulder Season
April – May, October
Fewer crowds, moderate prices, mild weather.
Off Season
November – March
Cooler temperatures; some regions may experience rain or snow.
Frequently Asked Questions
What is the current weather in Sarnia?
Current conditions in Sarnia: Mist, temperature 8°C, humidity 93%.
What is the best time to visit Sarnia?
The best time to visit Sarnia is typically June – September. Warm, dry summers — ideal for outdoor activities.
What is the climate like in Sarnia?
Sarnia is located at approximately 43° latitude. It has a temperate climate with warm summers and cold winters.
Does it rain a lot in Sarnia?
The wettest period in Sarnia is typically during November – March. Cooler temperatures; some regions may experience rain or snow.
What should I pack for a trip to Sarnia?
For visits to Sarnia during June – September: light clothing and sun protection. For November – March: layers and a waterproof jacket are recommended.
What are the public holidays in Sarnia in 2026?
View the 2026 public holidays for Sarnia on our Holidays page.
What are the GPS coordinates used for the weather forecast in Sarnia?
The weather forecast for Sarnia uses coordinates 42.9744, -82.4035.
What is the current temperature outside in Sarnia?
The current outdoor temperature in Sarnia is 8°C (46°F) with mist.
What is the hourly weather forecast for Sarnia today?
Today's hour-by-hour weather breakdown for Sarnia is shown in the Hourly Forecast section above, including temperature, rain chance, and conditions for each hour of the day.
What is the weather in Sarnia tomorrow hour by hour?
Tomorrow's forecast for Sarnia shows a high of 12°C and a low of 5°C. See the 3-Day Forecast section above for a full hourly breakdown.
What is the chance of rain today in Sarnia?
There is a 89% chance of rain in Sarnia today. Check the hourly forecast above for a time-by-time breakdown of when rain is most likely.
Is it going to rain today in Sarnia?
Yes, there is a 89% chance of rain in Sarnia today — consider carrying an umbrella. Check the hourly forecast above for the most likely rain windows.