Weather & Climate in St. Clair, ON
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
St. Clair experiences four distinct seasons with an average annual temperature of 49°F (9°C). Winters average 24°F in January while summers reach 73°F in July. Annual precipitation totals 35.3 inches. The area receives 9.5 inches of snow annually. The city sits at an elevation of 591 feet.
Temperature
24°F Jan (-5°C)
73°F Jul (23°C)
| Annual Average | 49.0°F |
| 9% below US avg | |
| January Average | 24°F (-5°C) |
| July Average | 73°F (23°C) |
Geography
| Elevation | 591 ft (180 m) |
| Area | 238.8 sq mi (618.6 km²) |
| Population Density | 61/sq mi |
| Coordinates | 42.3192°N, 82.8578°W |
| Timezone | America/Toronto |
Precipitation & Snow
Air Quality
Earthquake History
29 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M4.0.
| Jun 10, 2019 | 1 km NW of Timberlake, Ohio | M4.0 | 136 km | 2 km |
| Jun 30, 2003 | 6 km NW of Perry, Ohio | M3.6 | 149 km | 5 km |
| Mar 15, 1992 | 15 km NW of North Perry, Ohio | M3.5 | 141 km | 5 km |
| Jun 20, 2006 | 9 km WNW of North Perry, Ohio | M3.5 | 145 km | 5 km |
| Jan 26, 1991 | 1 km NNE of Mayfield Heights, Ohio | M3.4 | 145 km | 5 km |
| Apr 20, 2018 | Michigan | M3.4 | 26 km | 3 km |
| Jul 1, 2013 | 5 km NNW of Fairport Harbor, Ohio | M3.2 | 142 km | 5 km |
| Jan 9, 2008 | 6 km WNW of Mentor-on-the-Lake, Ohio | M3.1 | 136 km | 5 km |
| Mar 11, 2006 | 8 km NNW of Mentor-on-the-Lake, Ohio | M3.1 | 135 km | 5 km |
| Feb 23, 2011 | 18 km NE of Leamington, Canada | M3.0 | 40 km | 5 km |
| Apr 12, 2007 | 11 km NW of Put-in-Bay, Ohio | M2.8 | 67 km | 5 km |
| Sep 22, 1999 | 16 km NW of Mentor-on-the-Lake, Ohio | M2.8 | 127 km | 18 km |
| Jan 4, 2022 | 3 km NW of Timberlake, Ohio | M2.8 | 135 km | 5 km |
| Nov 25, 1998 | 1 km SSW of New London, Ohio | M2.7 | 144 km | 5 km |
| Mar 8, 2013 | 5 km NNW of Timberlake, Ohio | M2.7 | 133 km | 5 km |
| Apr 28, 2002 | Ohio | M2.7 | 133 km | 5 km |
| May 14, 2010 | 1 km ENE of Gibsonburg, Ohio | M2.7 | 110 km | 5 km |
| May 14, 2017 | 18 km ENE of Leamington, Canada | M2.6 | 42 km | 5 km |
| Jun 10, 2010 | 8 km NW of Mentor-on-the-Lake, Ohio | M2.6 | 133 km | 5 km |
| Jan 6, 2006 | 10 km NW of Mentor-on-the-Lake, Ohio | M2.6 | 131 km | 5 km |
Source: USGS Earthquake Catalog (M2.5+, 1990-2025). Sorted by magnitude.
Tsunami History
1 tsunami recorded within 500 km. Highest wave on record: 1.5 m (5 ft).
| Year | Location | Cause | Max Wave | Deaths | Distance |
| 1952 | LAKE HURON, MI | Avalanche | 1.5 m | - | 95 km |
Source: NOAA/NCEI Historical Tsunami Database.
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 24°F (-5°C) | 1.9 in | Coldest, Driest |
| February | 26°F (-3°C) | 2.0 in | |
| March | 36°F (2°C) | 2.7 in | |
| April | 47°F (8°C) | 3.2 in | |
| May | 59°F (15°C) | 3.2 in | |
| June | 68°F (20°C) | 3.3 in | |
| July | 73°F (23°C) | 3.4 in | Warmest |
| August | 71°F (22°C) | 3.3 in | |
| September | 64°F (18°C) | 3.7 in | Wettest |
| October | 52°F (11°C) | 2.6 in | |
| November | 41°F (5°C) | 3.2 in | |
| December | 30°F (-1°C) | 2.9 in |
St. Clair has a seasonal temperature swing of 49°F / from 24°F in January to 73°F in July. Total annual precipitation is 35.3 inches, with September being the wettest month (3.7") and January the driest (1.9").