Does hot weather affect how much power an extension cord can safely carry?

Yes, higher temperatures reduce an extension cord’s current capacity because copper wire has more resistance when hot, causing faster overheating. Most cords are rated at 60°C ambient, but direct sun can push ground temps to 120°F, derating capacity by 10-15 percent. Avoid running high-draw tools like space heaters or miter saws on long cords in July; if you must, go up a gauge. If the cord feels warm to the touch, it’s too small or too long for the job.