When to Turn On the Heat in Fall: Ideal Indoor Temperature and Thermostat Tips

As cooler weather arrives, many people wonder: When should I turn on the heat? The answer doesn’t depend on a date on the calendar—it depends on your indoor temperature and comfort level.

What Is the Ideal Indoor Temperature?

Health experts, including the World Health Organization, recommend keeping your home at 18°C (64°F) or warmer. This is particularly important for older adults, people with asthma, or anyone with heart conditions.

For healthy individuals, slightly cooler temperatures may be manageable with warm clothing or blankets. However, for most households, 64°F is considered the safe minimum.

Best Thermostat Settings for Fall and Winter

If you use a programmable thermostat, here are some guidelines:

• Set your thermostat to around 70°F (21°C) when you’re home and active.

• Lower it by 7–8°F while you’re asleep or away to save energy.

• This strategy can help reduce heating bills while still keeping your home comfortable.

Cooler temperatures at night can also improve sleep quality, especially when paired with warm bedding.

When to Turn On Your Heating System

So, when is the “right” time?

• If your indoor temperature drops below 64°F (18°C) for most of the day, it’s time to switch on the heat.

• If nighttime temperatures fall into the 50s°F (10–15°C), most homes will need heating.

Even if you prefer waiting, always run a test early in the fall to make sure your heating system is working. The worst time to discover a problem is on the coldest day of the season.