Grand River South, in Ontario, Canada, is home to roughly 9,600 people in the Eastern Time Zone at 43.5°N latitude.
Recent weather here gives a sense of typical conditions: in 2025, Grand River South recorded a mean annual temperature of 46°F, ranging from -9°F lows in January to 93°F highs in June, with about 31 inches of precipitation across the year.
View historical weather for Grand River South · More cities in Ontario