Best Thermostat Temperature for Winter in Ontario: Settings That Save

The best thermostat temperature for winter in most Ontario homes is about 20–21 °C when you are home and awake, and about 17–18 °C overnight or when the house is empty. That 2–3 °C setback typically saves roughly 5–10% on heating energy with a gas furnace or electric baseboards, while heat pump owners do better with smaller setbacks of 1–2 °C.

There is no single "correct" number. Comfort varies with age, health, activity, clothing and how drafty your home is. But the pattern of a comfortable daytime setting and a lower overnight and away setting is the most reliable free saving available in an Ontario winter.

What is the best thermostat temperature for winter in Ontario?

Situation	Suggested setting	Notes
Home and awake	20–21 °C	Raise slightly for infants, older adults or people with some health conditions
Asleep	17–18 °C	Many people sleep better in a cooler room
Out for the day (gas or baseboard heat)	17–18 °C	Program recovery to start 30–60 minutes before you return
Out for the day (heat pump)	19–20 °C	Small setback avoids backup heat on recovery
Away for several days	About 15–16 °C	Do not go much lower: frozen pipes and condensation risks
Cottage or vacant home	Seek advice	Plumbing, insurance and humidity all matter

A cooler home loses heat more slowly, because heat loss depends on the temperature difference between inside and outside. That is why a setback saves energy even though the furnace has to work to bring the temperature back up. The idea that "it takes more energy to reheat" is a myth for furnaces and baseboards.

How much does a thermostat setback save?

Here is the math for two common Ontario homes, using the typical 5–10% saving from a 2–3 °C setback overnight and while away.

Home	Annual heating energy (estimate)	Annual heating cost	5–10% saving
Detached home, gas furnace	2,000 m³ at 45¢/m³ + 13% HST	about $1,017	about $51–$102
Electric baseboard home	15,000 kWh at about 16.5¢/kWh (all-in, after HST and rebate)	about $2,475	about $124–$248

The saving is larger in colder regions and draftier homes, simply because they use more heat. A home in Ottawa, at roughly 4,500 heating degree days, or Sudbury and Thunder Bay at about 5,000–5,700, spends more on heat than one in Toronto at about 3,500, so the same percentage is worth more dollars. To see what a typical gas bill looks like across a year, read our post on the average gas bill in Ontario.

Tip: Turning the thermostat far higher than you want does not heat the house faster. A furnace delivers heat at the same rate whether you set it to 22 °C or 28 °C; a higher setting just overshoots.

Heat pump settings are different

With a heat pump, deep setbacks can cost you money. When the system tries to recover 3–4 °C on a cold morning, it may call on electric resistance backup, which uses two to three times as much electricity per unit of heat as the heat pump itself.

Heat pump approach	Typical result
Constant setting, around 20–21 °C	Steady, efficient operation; simplest
Small setback (1–2 °C) with slow recovery	Modest savings if the thermostat supports heat pump recovery
Large setback (3 °C or more)	Risk of backup heat and higher costs on cold days

A thermostat designed for heat pumps can limit backup heat and stage recovery gradually. See heat pump backup heat explained. In a hybrid system with a gas furnace, the controls decide when to switch fuel, so moderate setbacks are usually fine.

Does time of use matter for thermostat settings?

For gas heat, the time of day does not change the price. For electric heat and heat pumps on Time-of-Use, winter on-peak runs 7–11 a.m. and 5–7 p.m. on weekdays at 18.9¢/kWh, and off-peak is 9.1¢ from 7 p.m. to 7 a.m. Some homeowners pre-heat slightly before 7 a.m. and coast through the morning peak, but the savings are modest and comfort comes first.

On Ultra-Low Overnight, the weekday 4–9 p.m. on-peak price of 37.7¢ makes evening electric heating expensive. Many electrically heated homes are better off on TOU or Tiered.

Humidity, drafts and comfort

If 20 °C feels cold, the thermostat may not be the problem:

• Dry air feels colder. A relative humidity of about 30–40% is comfortable for most homes without causing window condensation. See winter humidity control.
• Drafts make rooms feel colder than the thermostat reads. Weatherstripping doors and sealing the basement rim joist can make a lower setting comfortable.
• Thermostat location matters. A thermostat near a supply register, a sunny window or the kitchen can misread the house.

Program it once, then leave it alone

1. Set a schedule: about 20–21 °C from wake-up to bedtime, 17–18 °C overnight, and a setback during weekday absences.
2. Start recovery 30–60 minutes before you wake up or return home.
3. Use vacation or "away" modes when travelling.
4. For heat pumps, choose small setbacks and confirm the backup heat lockout settings with your installer.

A smart thermostat makes this easier, especially for households with changing schedules. The Home Renovation Savings Program lists a $100 smart thermostat rebate through its product route; confirm details at saveonenergy.ca (opens in a new tab). Our smart thermostats guide covers which features matter, and our winter energy savings guide lists other low-cost steps for the season.

All savings figures in this post are estimates for illustration.