The summer heat is a very common cause of windshield damage. Heat causes windshields to expand, causing cracks and chips in the glass as it is in a vulnerable position within the frame.
Summer heat can also cause small chips or cracks to quickly spread into larger breaks. This is why we recommend getting a windshield repair as soon as you see minor windshield damage, in order to avoid needing a full windshield replacement.
Another reason why windshield cracks are common in the summer is because drivers usually crank up their air conditioning when they jump into their hot car during the summer. Imagine when you pop a couple of ice cubes into a warm drink. That popping sound is similar to what is happening to your windshield when you are blowing ice cold air onto it after it has been baking in the hot sun for hours.
Use caution during the summer if your windshield has any minor chips or cracks. Get your windshield professionally repaired as soon as possible, but in the meantime, do your best to park in the shade whenever possible. Also, keep your windows slightly cracked when it is parked so that the heat in the inside of your car does not get too intense. And if you can help it, slowly turn up your air conditioning so that you do not stress out your glass.