United States - weather in August

August is the last month of summer in the United States, and is typically the warmest of the year on the west coast (see Seattle, Los Angeles) and in the southernmost part (see the Gulf of Mexico states), while in the rest of the territory the warmest month is July.
Temperatures are mild to pleasantly warm on the Pacific Ocean coast (see Seattle, San Francisco, Los Angeles), where a cold sea current flows, while they are mitigated by altitude in the Rocky Mountains (see Helena, Denver). For the rest, it's warm to hot in the center-north and very hot in the south. In the deserts of the southwest (see Phoenix), dry heat reigns, while in the central-eastern part, influenced by the Gulf of Mexico, the humidity is higher and therefore the weather is sticky and unpleasant.
Furthermore, heat waves can occur in almost the entire territory, which are rarer and shorter in the north, while in the center-south they last longer and are accompanied by high humidity.
If we exclude the Pacific coast and the arid plateau known as Great Basin (see Utah, Nevada and southeastern Oregon), where summer is the driest season, the rains are from moderate to abundant in most of the territory.
Thunderstorms can break out even in the Great Plains, where there is little rain in the rest of the year. Also, in the arid southwestern states (Arizona, New Mexico, West Texas), July through September is the time of the "North American monsoon," which can bring thunderstorms from the Gulf of California.
In August, tornadoes are rarer in east-central United States than in the spring and early summer, however, they do occasionally occur, especially in the north, in the northern part of the Great Plains.
From June to November is the season of hurricanes, which can affect the states bordering the Gulf of Mexico (Texas, Louisiana, Mississippi, Alabama and Florida) and the southernmost states of the Atlantic (Georgia, North and South Carolina). Occasionally, hurricanes can move northward and affect the other Atlantic coastal states as well.
More rarely, a hurricane from the Pacific to the west of Mexico, usually weakened, can affect the southwest (southern California, Arizona, New Mexico). In August, the period when hurricanes are most likely begins, which lasts until October.

The sea is warm enough for swimming in the Gulf of Mexico, in Florida and in the Atlantic coast states up to New York, where it reaches 23 °C (73.5 °F) in August. In the Great Lakes, August is the month in which the water reaches its highest temperature, and while it is still cool in the northern lakes, it reaches 23.5 °C (74.5 °F) on the southern shore of Lake Erie (see Cleveland).
Instead, to the west, on the Pacific Ocean, the sea is cold even in California, due to the aforementioned cold sea current.


See also: United States, the weather in July - September
The climate of United States