It is the peak of summer. The sun is blazing, your air conditioner is running full blast, and suddenly—click. The power goes out.
If you find yourself standing in front of your electrical panel wondering, "Can hot weather cause my breaker to trip?" the short answer is yes.
Heat is the enemy of electrical systems. While circuit breakers are designed to protect your home, extreme summer temperatures can make them more sensitive, leading to "nuisance tripping" or revealing underlying electrical issues.
Here is everything you need to know about why your power trips when it’s hot out and when you need to call The Wire Guy.
To understand why summer heat causes power outages, you have to understand how a standard circuit breaker works. Most homes use thermal-magnetic breakers. These devices detect dangerous currents using two methods:
Inside the breaker, there is a bimetallic strip. As electricity flows through it, the strip heats up. If too much current flows through, the strip gets too hot, bends, and snaps the circuit open to cut the power.

The Problem with Summer: Circuit breakers are calibrated to operate at specific temperatures (usually around 77°F or 25°C). If your electrical panel is located in a hot garage or on an exterior wall in direct sunlight, the ambient temperature raises the baseline heat of that bimetallic strip.
Because the breaker is already hot from the weather, it takes less electrical current to push it over the edge. A load that wouldn't trip the breaker in winter might trip it easily in July.
While ambient heat is a factor, it is usually a combination of heat plus high demand that causes the trip.
Your air conditioner works much harder when it is 100°F outside than when it is 80°F.
Take a look at your electrical panel. Is it mounted on the south or west side of your home? Does the sun beat down on the metal box all afternoon?The temperature inside a metal gray box in direct sunlight can be 30° to 50° hotter than the air temperature. This "oven effect" can cause breakers to trip even if you aren't using maximum power.
Physics dictates that metal expands when it gets hot and contracts when it cools.Over years of seasonal temperature swings, the copper or aluminum wires in your panel can expand and contract enough to loosen the screws holding them in place. A loose connection creates electrical resistance, which generates more heat, creating a cycle that eventually trips the breaker or, worse, melts the wire insulation.
Like any mechanical device, circuit breakers wear out. If your breakers are decades old and have tripped many times in the past, their internal springs and contacts may be weak. Extreme heat is often the final straw for an aging breaker.
If your breaker trips on a hot day, follow these steps safely:
Safety Warning: If a breaker trips immediately after you reset it, or if you hear a buzzing sound or smell burning plastic, stop. These are signs of a dangerous electrical arc or short.
You can’t control the weather, but you can control your electrical system.
If you are frustrated by constant flickering lights or breakers that won't stay on, it’s time to call in the pros. Dealing with electrical panels—especially those that are overheating—is dangerous work.
Contact The Wire Guy if:
Don't let the heat leave you in the dark.
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