when will it start to cool down

The cooling down is already starting around late August 2025. Specifically, a significant cold front began moving through parts of the U.S. around August 22-24, bringing temperatures 10 to 25 degrees below normal in many regions such as the Midwest, Great Lakes, Northeast, and northern parts of the U.S. This cooldown is forecast to persist through the final days of August and into early September, with an outbreak of cooler air mass from Canada extending into the South U.S. by early to mid-next week. Some areas are experiencing temperatures that feel similar to late September or early October quite early, and this cooler period may linger for several days to a week or more in many places. This marks a substantial and relatively early transition to fall-like weather, breaking from the typical August heat patterns.