Environment

Extreme Temperature

Key Messages
Extreme Heat Events
Tropical Nights
Extreme Cold Events
Technical Notes

Key Messages

Climate change is expected to increase the frequency and intensity of extreme temperature events.
Temperature extremes can pose a risk to human health and to infrastructure.
Extreme temperatures have been recorded across the health unit region over the past 20 years.
There is no clear pattern for extreme heat or extreme cold in recent years, although 2005 was an unusually hot year, and the winter of 2003/2004 included an usually long deep freeze.

Extreme Heat Events

From 2001 to 2022, there were an average of 1.3 extreme heat days each year across the health unit region, which corresponds to approximately one extreme heat event (2+ days meeting criteria) each year.
There were fewer extreme heat days reported in Muskoka District than at the two Simcoe County weather stations.
There is no clear pattern, although there were notable spikes in the number of extreme heat days in 2001, 2002, and 2005, especially at Egbert weather station in South Simcoe. 2005 was the warmest summer on record in Ontario.
No extreme heat days were reported in 2004, 2008, 2009, 2014 to 2017 or 2021.

191126ExtremeHeatDays2001to2018

Tropical nights

From 2001 to 2022 there were an average of two tropical nights per year across the health unit region.
Most of these were observed at the Simcoe County weather stations (Barrie-Oro and Egbert).
Barrie-Oro reported a large number of tropical nights in 2001 (8) and 2002 (13), before dropping to two or fewer tropical nights most years. A higher number of tropical nights were observed on average in Egbert, which is the most southern weather station in the region.

191126TropicalNights2001to2018

Extreme Cold Events

From 2001 to 2022, the criteria for extreme cold was met an average of one day per year across the region.
The number of days meeting extreme cold warning criteria varied from year to year, across the three weather stations in the health unit region.
Particularly cold winters were experienced in 2003/2004, 2008/2009, and 2013/2014.
In 2003/2004, there were seven days meeting the criteria for extreme cold at Barrie-Oro. Despite being a generally warm winter, a period of deep freeze was experienced in early 2004 across Canada.

191126ExtremeColdDays2001to2018

Technical Notes

There are three weather stations in the Simcoe and Muskoka region which are used to monitor and report on temperature and precipitation in the region.Environment and Climate Change Canada operate and report on data obtained from these weather stations.

The stations are categorized as: Barrie-Oro (near Barrie), Egbert (in Essa), and Beatrice (near Bracebridge).

These stations provide general information about local weather. Temperatures in urban areas may be higher than those measured at local weather stations due to the urban heat island effect.