Extreme cold
How cold is too cold to sleep outside?
For someone outside for long stretches without enough protective clothing, the City of Toronto says the risk of hypothermia and frostbite starts at a wind chill of minus 10, and at minus 28 exposed skin can freeze in 10 to 30 minutes12. Being wet raises the risk at any temperature: you lose heat faster when you are wet3, and feet that stay wet can get trench foot at temperatures as high as 15.5°C4.
Toronto opens its Warming Centres when the forecast reaches minus 55.
Tonight
If you are outside and need somewhere warm.
The City activates Warming Centres when Environment and Climate Change Canada forecasts minus 5°C, or issues a winter weather event warning. They open at 5 p.m. that day and stay open 24 hours until the City closes them, and you can walk in without calling anyone first5.
For a shelter bed, call Central Intake at 416-338-4766, any time, day or night6.
The numbers
What happens at each temperature, and what Toronto does.
Wind chill is how cold it feels on bare skin once the wind is counted in. Each row says whether it means the air temperature or the wind chill, because the City's triggers and the health figures do not always use the same one.
| At | What happens | Source |
|---|---|---|
| 15.5°C, with feet wet for hours | Trench foot can develop | CCOHS4 |
| Cold but above freezing, for several hours at a time | Chilblains, from repeated exposure | CCOHS4 |
| Skin itself below 0°C | Frostbite: the tissue begins to freeze | CCOHS4 |
| Forecast of minus 5°C | The City activates Warming Centres, open from 5 p.m. | City of Toronto5 |
| Wind chill of minus 10 | Risk of hypothermia and frostbite for anyone outside for long periods without enough protection | City of Toronto12 |
| Minus 15°C | Two more surge Warming Centres open | City of Toronto5 |
| Wind chill of minus 28 | Exposed skin can freeze in 10 to 30 minutes | City of Toronto2 |
| Minus 30, air temperature or wind chill, for at least 2 hours | Environment and Climate Change Canada issues an extreme cold alert for southern Ontario, Toronto included | City of Toronto7 |
| Wind chill of minus 40 | Exposed skin can freeze in 5 to 10 minutes | City of Toronto2 |
Someone sleeping outside is out for the whole night, and mostly still. Health Canada's first advice against the cold is to find shelter and keep your muscles moving3, and a person asleep in a doorway can do neither. CCOHS adds wet clothing, wind, being tired, and alcohol or nicotine to the list of things that raise the risk4.
Signs
Signs of hypothermia and frostbite in someone else.
Health Canada describes hypothermia in three stages3:
- Shivering, goosebumps, hands going numb.
- Muscles that will not work together, and movements that turn slow and laboured.
- Trouble speaking, thinking and walking.
At the second or third stage, call 9113.
Frostbite usually starts with numbness4. In mild frostbite, sometimes called frostnip, the skin looks yellowish or white but is still soft to the touch; in severe frostbite it becomes discoloured and can turn black3. Do not rub frostbitten skin, because rubbing can do more damage34. Health Canada's first aid for the cold includes getting to shelter and drinking warm, sweet liquids3.
What the City does
Two cold triggers, 25 degrees apart.
The City activates Warming Centres when Environment and Climate Change Canada forecasts minus 5, or issues a winter weather event warning5. Five sites open at that point, and two surge sites join them at minus 15. If a site is full, the City helps with transportation to one that has space5. Last winter, Warming Centres ran from November 15, 2025 to April 15, 20268, and the City publishes each winter's plan in the fall.
The extreme cold alert is a federal one. Environment and Climate Change Canada issues it for southern Ontario, Toronto included, when the air temperature or the wind chill is forecast to reach minus 30 for at least two hours7.
Older City news releases announce "Extreme Cold Weather Alerts" called by the City itself. The City's current cold-weather pages describe the two triggers above, and we have written this page to match them57.
During extreme cold, the City sends out extra street outreach teams to encourage people to come indoors8, and Streets to Homes outreach adds wellness checks and referrals to Warming Centres during extreme weather alerts9.
To check tonight: Environment and Climate Change Canada's forecast and alerts for Toronto at weather.gc.ca, or call 311.
Helping someone
If you are worried about someone outside.
Ask if they are okay, and whether they want help getting somewhere warm. If they do, the Warming Centre addresses are on our shelter page, and if a site is full the City helps with transportation to another5.
If they would rather stay where they are, call 311 and describe where they are. That reaches the City's Streets to Homes outreach, 24 hours a day, and in winter outreach workers carry blankets and sleeping bags9.
Call 911 if the person is unresponsive, shows the second or third stage of hypothermia, or you do not think they will get through the night where they are3.
Questions people ask
The short answers.
How cold is too cold for homeless people to sleep outside?
When do warming centres open in Toronto?
When Environment and Climate Change Canada forecasts minus 5°C, or issues a winter weather event warning. They open at 5 p.m. that day, stay open 24 hours until the City closes them, and take walk-ins5. The addresses are on our shelter page.
Is there an extreme cold weather alert in Toronto today?
Can the cold hurt someone when it is above freezing?
What are the signs of hypothermia?
About this page
Who put this page up.
Engage and Change is a Toronto charity. We do not run shelters or Warming Centres. Each January since 1999 we have packed winter survival kits, and more than 200 front-line agencies across the GTA, shelters and outreach programs among them, hand them to the people they work with10.
If you came here worried about someone and want to help past tonight, $50 helps build one of those kits, with a sleeping bag, a backpack, socks, a hat and gloves among its 30+ new items10.
Sources
- City of Toronto, Cold Weather Information for Health Professionals. toronto.ca Cold Weather Information for Health Professionals.
- City of Toronto, Stay Warm (wind chill table). Date modified December 24, 2025. toronto.ca Stay Warm.
- Health Canada, Extreme cold. Date modified October 19, 2021. canada.ca Extreme cold.
- Canadian Centre for Occupational Health and Safety, Cold Environments: Health Effects and First Aid. ccohs.ca Cold Environments.
- City of Toronto, Warming Centres. Date modified April 8, 2026. toronto.ca Warming Centres.
- City of Toronto, Central Intake. toronto.ca Central Intake.
- City of Toronto, Extreme Cold Weather. Date modified October 17, 2023. toronto.ca Extreme Cold Weather.
- City of Toronto, 2025/2026 Winter Services Plan. News release, November 7, 2025. toronto.ca 2025/2026 Winter Services Plan.
- City of Toronto, Streets to Homes Street Outreach Support Program. toronto.ca Streets to Homes.
- Engage and Change. Project Winter Survival kit list and program figures, engageandchange.org, as of October 2026. Project Winter Survival.
Numbers and sources checked October 11, 2026. Warming Centre details are re-checked each November.