How the 2026 Heat Wave Trends Are Changing AC Usage in Northern Climates

How the 2026 Heat Wave Trends Are Changing AC Usage in Northern Climates

It’s expected that La Niña will give way to ENSO-neutral or El Niño weather patterns in the coming months. Predictions indicate that Western states will experience warmer, drier conditions, while southern regions will face cooler, wetter weather. 

Meanwhile, those of us in the northern states should prepare for a drier, hotter summer. The NOAA forecasts that northern states like Illinois and parts of Canada will be warmer than usual.

When heat waves hit and temperatures rise, air conditioning use also increases. Your AC runs longer each day. You might find yourself needing AC 24/7 to keep your living areas and home office cool during the day and your bedrooms cool at night. 

The Northern States’ “New Normals” for Summer Weather

Since 1960, the hottest temperatures of the year have trended towards the 90s or higher. Recorded highs in Illinois between 1960 and 2025 are:

• 1960s – 90.8°F in 1966
• 1970s – 88.9°F in 1977
• 1980s – 91.3°F in 1983
• 1990s – 89.2°F in 1999
• 2000s – 89.4°F in 2007
• 2010s – 94.4°F in 2012
• 2020s – 87.6°F in 2025

These are the highest temperatures recorded for all of Illinois. Large cities like Chicago are “heat islands” and experience temperature increases of 1 to 7°F. Heat islands are urban areas with less vegetation, where asphalt roads, parking lots, concrete buildings, and dark roofs absorb sunlight all day. At night, that trapped heat is released, preventing temperatures from dropping.

Chicago’s 1995 heat wave saw temperatures exceed 100°F for multiple days, and 700 Chicagoans died from the heat. Since then, the heat vulnerability index (HVI) has helped alert the public and assist those who need access to cooling centers or home cooling programs.

Navigating Power Grid Strain

As more data centers open in the U.S., there’s a risk of overloading the power grids. The Illinois 2025 Resource Adequacy Study confirmed everything ComEd reported. Energy resources must expand to prevent impacts on local communities and residents. If no action is taken, grid shortfalls could begin as early as 2029.

One aspect of these shortfalls relates to hotter summers. As more people run their air conditioning systems day and night, it puts pressure on the power grid. If thousands of people all use their AC units at maximum fan speeds and low temperature settings, it will strain systems in Chicagoland.

In winter, lowering your thermostat from 70°F to 68°F saves about 6% on energy use. The same applies in summer. Instead of setting the AC to 65°F, aim for 68°F to reduce energy consumption. There are other ways to stay cool and do your part to avoid outages or rolling blackouts.

Understanding Window Thermal Load and the Value of Insulation

Once your home’s AC system cools your rooms to the desired temperature, the time before it cycles on again depends on your house. If it’s poorly insulated, that cool air escapes through gaps around doors and windows or into the attic or roof space.

A well-insulated home traps cold air and keeps your system from running nonstop, which wastes energy, increases your bills, and shortens your HVAC equipment’s lifespan. Schedule an energy assessment with your electric company to identify where your home’s insulation and weatherization need improvement. Eligible ComEd customers receive a free energy assessment. 

In Chicago, Zone 5 recommendations for insulation are:

• R5 to R10 for uninsulated walls
• R10 for insulated 2×4 walls
• R15 for basements or crawlspaces
• R19 for floors
• R49 for an attic with 3 or 4 inches of existing insulation
• R60 for an uninsulated or poorly insulated attic

The other thing to consider is heat gain through your windows and skylights. Solar radiation passes through windows, which heats your rooms. Blackout blinds and curtains prevent solar heat gain. When it’s sunny, keep your blinds closed.

Window AC Units Aren’t Your Most Efficient Option

Window AC units are convenient, but they’re not always the most efficient option. You also need room for storage during the winter. There are additional options available today. 

Ductless HVAC systems, also known as mini-splits, are energy-efficient air conditioning units in which an indoor wall-mounted unit connects to an outdoor compressor through the wall. You don’t need an existing furnace, which makes them ideal for homes with a boiler. In winter, they help with heating, offering an extra benefit.

Heat pump systems are all-electric and transfer heat between indoor and outdoor air, making them more efficient than traditional HVAC systems. You have the outdoor compressor and an indoor unit that connects to ducts and cools or heats the indoor air to match the thermostat setting.

SpacePak Systems are perfect if you lack ducts or space for them. These 2-inch flexible ducts easily fit into ceilings, floors, and walls. Major renovations aren’t needed, allowing you to create energy-efficient zones without hot or cold spots. They’re also better at removing summer’s humid air than a mini split.

Consider an HVAC Upgrade and Keep Your System Maintained

If you already have ducts and an existing furnace, consider installing an AC. You’ll have heat running through the ducts all winter and cool, filtered air all summer. If your existing heating or AC equipment is over 10 years old, it’s a good idea to have it evaluated.

Changes to the types of coolants allowed in 2026 will make repairing older systems more costly. Additionally, many HVAC systems will last only about 15 to 20 years. A good rule of thumb is to replace the system if a repair costs about 50% of the price of a new one.

Once you have a system keeping your home cool, don’t overlook the importance of yearly maintenance. When a trained HVAC technician cleans, inspects, and makes repairs to any components nearing failure, you end up with a system that lasts longer and delivers the energy-efficient cooling you expect, no matter how hot it gets outside.

Rebates Save You Money

Work with a local HVAC installer. ComEd offers discounts of up to $2,000 on mini-split heat pumps if you work with a qualified HVAC installer. Ductless and mixed-use mini-split heat pumps have discounts of up to $1,000. If you add an ENERGY STAR Smart thermostat, an additional $75 is available.

Air Blue is a participating contractor. We work with your customers to ensure their home is cool and comfortable all summer long. Our team helps you decide whether a heat pump system or a full HVAC system with heating and cooling is the better investment for your needs. We’ll also help you qualify for any local, manufacturer, or federal rebates or offers that lower the cost of your new cooling system.