Sarnia Climate by Month
Sarnia, Ontario, Canada
Warm summers and freezing winters, with rain spread through the year.
Sarnia has warm summers and freezing winters, with rain spread through the year. Expect highs of 81°F (27°C) in July and 31°F (0°C) in January, with the coldest nights (January) near 18°F (-8°C). About 34 in (857 mm) of rain falls in a typical year, with no clear rainy season.
- Warmest month
- 81°F(27°C)
- Average high, July
- Coldest nights
- 18°F(-8°C)
- Average low, January
- Rain per year
- 34 in(857 mm)
- No clear rainy season
- Humidity
- 73%
- Sunniest: July
Best and worst months in Sarnia
Best for weatherJune, August and September are the best time for weather in Sarnia: highs near 77°F (25°C) and about 3.3 in (84 mm) of rain a month.
Least pleasantJanuary and February are the least pleasant; January is the coldest, with highs of only 31°F (0°C).
Comfort combines how close the afternoon high is to 75°F (24°C) with how much rain falls and how humid it is. See where the weather is best in June.
Temperature and rain through the year
Highs and lows (°F)
Average highAverage low
Rain (in per month)
Sarnia weather by month
| Month | High | Low | Rain | Humidity | Sun |
|---|---|---|---|---|---|
| JanJanuary | 31°F(0°C) | 18°F(-8°C) | 2.3 in(58 mm) | 88% | 1.3 |
| FebFebruary | 33°F(1°C) | 18°F(-8°C) | 2.2 in(56 mm) | 85% | 2.3 |
| MarMarch | 42°F(5°C) | 26°F(-3°C) | 2.1 in(53 mm) | 76% | 3.5 |
| AprApril | 53°F(12°C) | 36°F(2°C) | 3.1 in(78 mm) | 70% | 4.4 |
| MayMay | 66°F(19°C) | 46°F(8°C) | 3.2 in(81 mm) | 65% | 5.2 |
| JunJuneBest | 76°F(25°C) | 56°F(13°C) | 3.6 in(91 mm) | 68% | 5.9 |
| JulJuly | 81°F(27°C) | 62°F(17°C) | 2.7 in(69 mm) | 68% | 6.0 |
| AugAugustBest | 80°F(27°C) | 62°F(16°C) | 2.8 in(72 mm) | 70% | 5.1 |
| SepSeptemberBest | 74°F(23°C) | 55°F(13°C) | 3.5 in(89 mm) | 72% | 4.2 |
| OctOctober | 62°F(16°C) | 45°F(7°C) | 3.1 in(78 mm) | 73% | 2.5 |
| NovNovember | 48°F(9°C) | 34°F(1°C) | 2.8 in(72 mm) | 69% | 1.5 |
| DecDecember | 37°F(3°C) | 25°F(-4°C) | 2.4 in(60 mm) | 68% | 1.1 |
1991–2020 averages. Sun is solar radiation in kWh/m² per day. Highlighted: the most comfortable months.
Places with a similar climate
All 20 places like Sarnia →- 🇺🇸MuskegonMichigan, United States · Pop. 38k99%matchSame winter lowsSame summer highsSarnia vs Muskegon →
- 🇺🇸AuburnNew York, United States · Pop. 27k99%matchSame summer highsSame winter lowsSarnia vs Auburn →
- 🇺🇸IthacaNew York, United States · Pop. 31k99%matchSame summer highsSame winter lowsSarnia vs Ithaca →
- 🇺🇸RochesterNew York, United States · Pop. 210k99%matchSame winter lowsSimilar rainfallSarnia vs Rochester →
- 🇺🇸VestalNew York, United States · Pop. 28k99%matchSame summer highsSame winter lowsSarnia vs Vestal →