Grand St. Thomas
Ideal air quality for outdoor Canadian activities and sports.
Grand St. Thomas Live Precipitation Radar
Full Screen ViewGrand St. Thomas Live Doppler RadarMSC Dual-Pol
Grand St. Thomas, ON • Lat: 42.36° N, Lon: 91.31° W • Sweep 10m
Grand St. Thomas 30-Year Weather History & Monthly Averages
Explore month-by-month temperatures, annual snowfall in cm, rainy days, and historical record highs and lows.
Grand St. Thomas Air Quality & Wildfire Smoke Report
Detailed Canadian AQHI breakdown, fine particulate matter (PM2.5), ground-level ozone, and health guidance.
Frequently Asked Questions About Weather in Grand St. Thomas, ON
What is the current temperature and conditions in Grand St. Thomas?
As of today, the temperature in Grand St. Thomas is 19.6°C with overcast. The apparent temperature (feels like) is 21.2°C with relative humidity at 94%.
How does Wind Chill and Humidex affect Grand St. Thomas?
During warmer conditions, the Canadian Humidex indicates comfort levels. The current Humidex is 20 (Comfortable).
What is the Air Quality Health Index (AQHI) for Grand St. Thomas?
The current AQHI for Grand St. Thomas is 3 (Low Risk). It is calculated based on ground-level ozone, fine particulate matter (PM2.5), and nitrogen dioxide levels according to Health Canada standards.
Where does the meteorological data for Grand St. Thomas come from?
Forecasts are generated using high-resolution Canadian Deterministic Prediction System (HRDPS 2.5km) and Global Environmental Multiscale (GEM) models alongside official Environment and Climate Change Canada Doppler radar feeds.