How to Save Energy During a Heat Wave

According to the National Weather Service, a heat wave is officially defined as unusually high temperatures lasting more than two days. Extreme heat waves and warmer temperatures have become a more frequent issue in the last few years. In fact, June 2025 was one of the top three hottest Junes on record, coming in just below 2023 and 2024.

During a heat wave, energy demand often spikes as residents rely on air conditioning to stay cool. Increased energy usage can lead to higher electricity bills, overload the grid, and trigger rolling blackouts. Luckily, there are a few things you can do to stay safe during a heat wave and manage your energy usage.

Heat waves pose a serious threat to your health and safety. Extreme heat is most dangerous for young children and people with health conditions, but it can affect everyone. Use the following tips to help keep yourself and your loved ones safe during a heat wave.

1. Limit outdoor activities

If there is a heat wave in your area, it’s best to avoid outdoor activities to limit the risk of overheating. Delay yard work, sports, and other outdoor activities until the heat wave has passed. If you do have to go outside, dress in lightweight, loose-fitting clothes and stay hydrated. Plan to stay in cool, air-conditioned spaces as much as possible. If you don’t have air conditioning in your home, consider spending time in a cool public space, such as your local library, shopping mall, or museum.

2. Prepare for emergencies

It’s best to prepare for the worst and hope for the best during a heat wave. Gathering emergency supplies in advance can make it easier to manage during a heat wave, especially if a power outage or rolling blackout occurs. Our Choose Energy experts recommend putting together an emergency kit with essential supplies, including clean drinking water, non-perishable food, medications, and a first aid kit. Our power outage guide provides more details on how to build an emergency kit.

3. Stay hydrated

According to the Red Cross, the average person should drink three-quarters of a gallon of water daily to stay properly hydrated. During a heat wave, it’s important to drink enough water to stay hydrated and cool, especially if you have to go outside. Avoid drinks that could dehydrate you, like alcohol or caffeine.

4. Check before you lock

If you need to drive during a heat wave, be sure to check your car for children, pets, or other passengers before exiting. Taking the extra few seconds to check will give you peace of mind and help you avoid a grim mistake.

The reality is that your energy bill will likely increase during the summer, especially during a heat wave, if you use AC to stay cool. However, you can implement energy-saving tactics to keep your summer energy costs from getting too high. Use these strategies to stay cool and decrease your reliance on AC.

Tip: Review our guide on how to reduce your energy bill for advice that works year-round.

1. Use ceiling fans

While ceiling fans won’t replace air conditioning, they can keep air circulating in your home and take some of the strain off your HVAC unit. Using your ceiling fans may let you raise your thermostat a few degrees, which can significantly reduce your energy use during a heat wave.

2. Seal doors and windows

Check your home’s window seals and weather strips around exterior doors to make sure there aren’t any gaps. Sealing leaks will prevent hot air from entering your home and ensure the cool air doesn’t escape.

3. Replace your HVAC filters monthly

Replace the air filters on your HVAC unit every month in summer. Your filters may collect more debris if your AC runs frequently. Changing them will help keep your airflow clean and ensure your unit is working efficiently.

Our advice: Schedule HVAC maintenance before summer arrives to ensure your entire HVAC unit is operating properly.

4. Run appliances at night

You can lower your energy usage and limit strain on the grid by running appliances overnight. Peak energy usage hours are normally from 7 a.m. to 11 p.m. on weekdays. If you have a time-of-use energy plan, rates are often higher during peak hours and lower during off-peak hours. Run large appliances, such as your dishwasher or washing machine, overnight during off-peak hours.

5. Sign up for a plan based on your usage

The best way to get affordable energy bills is to choose a plan that aligns with your average monthly usage. Check your past energy bills to learn how many kilowatt-hours (kWh) of electricity you typically use. Then, you can filter for plans on Choose Energy that match your usage. You can also call the number on your screen to speak with one of our energy agents. Once they ask you a few questions about your home and budget, they can help you determine which plan is best for you.

What qualifies as a heat wave?

A heat wave is a period of two or more days of abnormally hot weather. Heat waves are relative to the climate. For example, a hot day in Texas will likely be warmer compared to one in Washington. Be sure to check weather reports for your area to stay informed about upcoming heat waves.

What should I set my thermostat to during a heat wave?

The Department of Energy recommends setting your AC to 78 degrees during the day. Raising the temperature on your AC unit even a few degrees can help to lower your energy usage and limit the strain on the grid. But don’t sacrifice comfort in favor of savings; it’s important to stay cool and safe during a heat wave.

Why is my electricity bill so much higher in the summer?

In the summer months, residents often use more electricity if they run the AC regularly to stay cool. The more energy you use in a billing period, the higher your bill will be. Regularly maintaining your AC unit can help keep your monthly bills in check.

How can I cool my home without lowering the AC?

Cooling your home is important during a heat wave, but it can also quickly drive up your electric bill. If you’d like to avoid lowering your thermostat, you can keep cool by turning on indoor fans, closing blinds and curtains, and wearing lightweight clothing.

How much electricity does a window AC unit use?

Based on common ENERGY STAR models, you can expect a window AC unit to use between 0.5 and 1.5 kWh of electricity per hour it’s running. The amount of energy it uses will vary depending on your unit’s size and efficiency. Typically, a smaller unit will use less electricity than a larger one.