United States - weather in July

July is the central month of summer in the United States, and is the warmest of the year in most of the country, with the exception of the west coast (see Seattle, San Francisco, Los Angeles) and of the southernmost part (see the states of the Gulf of Mexico), where the warmest month is usually August.
Temperatures are mild to pleasantly warm on the Pacific 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, even though they often decrease a little compared to June.
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 July, tornadoes are rarer in east-central United States than in previous months, however, they can 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). More rarely, a hurricane from the Pacific to the west of Mexico, usually weakened, can affect the southwest (southern California, Arizona, New Mexico). However, hurricanes are still rare in July, and the time when they are most likely is from August to October.
The United States is located at medium latitudes, however, in July the days are long, especially in the north, where they last more than 15 hours.

The sea is warm enough for swimming in the Gulf of Mexico, in Florida and on the Atlantic coast as far north as Virginia, but ultimately as far north as Maryland, Delaware and New Jersey.
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 June - August
The climate of United States