Managing your rental
Minimum heat in Ontario rentals: the province's rule and city by-laws
How warm an Ontario landlord must keep a rental, and when: the province's 20°C rule and the higher or longer rules of 17 cities, each from its source.
By the Tenant.ca teamUpdated 2 min read
In this guide4 parts
The short answer
Across Ontario, when the landlord supplies the heat, it is a vital service from September 1 to June 15, and it has to keep every lived-in room at 20°C or more, measured 1.5 metres above the floor and one metre from the outside walls. That is O. Reg. 516/06, section 4, under the Residential Tenancies Act.
Many cities set more: a higher temperature, a different season, or a rule that applies all year. Where a city's rule and the province's both apply, keep to whichever asks more of you.
City rules, checked November 7, 2026
Each row comes from the City's own page or by-law, linked below. Some by-laws set what the heating system must be able to do rather than a season, and the table says so. Cities change these rules, so check the City's page before you rely on a row.
| Where | The rule |
|---|---|
| Ontario | At least 20°C from September 1 to June 15 when the landlord supplies the heat (O. Reg. 516/06, section 4). |
| Toronto | At least 21°C from October 1 to May 15 when the landlord pays for heat. Air conditioning the landlord provides must keep the unit at 26°C or less from June 1 to September 30. |
| Mississauga | At least 20°C throughout the year. |
| Brampton | At least 20°C from September 15 to June 1 (Vital Services By-law). |
| Vaughan | At least 21°C from September 15 to May 15, and no more than 26°C from May 16 to September 14 (Vital Services By-law). |
| Markham | At least 20°C from 6 a.m. to 11 p.m. and 16°C overnight (Property Standards By-law 2017-26). |
| Richmond Hill | A heating system able to keep habitable rooms at 20°C or more (Property Standards By-law 62-24). |
| Oakville | Heating able to keep 20°C (Property Standards By-law). |
| Ajax | At least 20°C from September 15 to May 31 when the landlord heats the unit (By-law 19-2026). |
| Whitby | At least 20°C from September 15 to May 31 when the landlord pays for heat (By-law 8187-25). |
| Oshawa | At least 22°C from September 1 to June 15. |
| Aurora | At least 20°C from September 15 to June 1 (By-law 6544-23). |
| Ottawa | At least 20°C from 6 a.m. to 11 p.m. and 16.67°C overnight, at all times, when the landlord normally pays for heat (Heat By-law 2010-210). |
| Hamilton | A heating system able to keep habitable rooms at 20°C or more during normal hours of occupancy (Property Standards By-law 23-162). |
| London | At least 20°C from 6 a.m. to 11 p.m. and 18°C at other times, from September 15 to June 15 (Vital Services By-law PH-6). |
| Waterloo | At least 21°C (Adequate Heat By-law 2017-001). |
| Brantford | A heating system able to keep 21°C during normal hours of occupancy, when heat is needed for health (Municipal Code chapter 465). |
| Windsor | At least 22°C in the accommodation available to the tenant (Building and Property Standards By-law 148-2025). |
- City of Toronto: indoor temperatures in rental unitstoronto.ca
- City of Mississauga: property standardsmississauga.ca
- City of Brampton: adequate heatbrampton.ca
- City of Vaughan: vital servicesvaughan.ca
- City of Markham: property standardsmarkham.ca
- City of Richmond Hill: Property Standards By-law 62-24 (PDF)richmondhill.ca
- Town of Oakville: property standardsoakville.ca
- Town of Ajax: Rented Dwelling Temperature By-law 19-2026 (PDF)ajax.ca
- Town of Whitby: Rental Unit Vital Services By-law 8187-25 (PDF)whitby.ca
- City of Oshawa: tenantsoshawa.ca
- Town of Aurora: Vital Services By-law 6544-23 (PDF)aurora.ca
- City of Ottawa: Heat By-law 2010-210ottawa.ca
- City of Hamilton: Property Standards By-law 23-162 (PDF)hamilton.ca
- City of London: Vital Services By-law PH-6london.ca
- City of Waterloo: Adequate Heat By-lawwaterloo.ca
- City of Brantford: Municipal Code chapter 465 (PDF)brantford.ca
- City of Windsor: Building and Property Standards By-law 148-2025 (PDF)citywindsor.ca
What the province also requires
Ontario's maintenance standards, O. Reg. 517/06, add these, wherever the rental is.
- The building's heating equipment has to be able to keep lived-in rooms at 20°C or more
- A portable heater can't be a unit's main source of heat
- When the tenant controls the temperature and the main heat source can keep 20°C, the 20°C rule in the regulation doesn't apply
If the heat fails
Treat a heating failure in season as an emergency. A landlord can't withhold, or deliberately interfere with, a vital service the landlord supplies (Residential Tenancies Act, section 21), and a tenant can call the City, which can inspect and order the work.
Under Tenant.ca's management, an urgent problem such as a heating failure is dealt with first and reported to you, and the tenant gets written notice before anyone enters except in an emergency.
This page is general information, not legal advice. It reflects the province's regulations and the City pages and by-laws linked above as read on November 7, 2026.