United States - weather in May

May is the last month of spring in the United States.
Temperatures are mild in the north, both in the west and in the east, and already hot in the extreme south, not only in the deserts of the south-west (see Phoenix), but also on the coast of the Gulf of Mexico (see New Orleans) and in Florida (see Miami), where the daily average exceeds 25 °C.
However, at the beginning of the month it can still be cold and snow, and the temperature can still drop to 0 °C (32 °F) or slightly below in the interior of the north (see Fargo), in the Rockies also at intermediate elevations (see Helena, Denver), and in the northern part of the Great Lakes.
Instead, during the month there may be hot periods, during which the temperature can reach 30 °C (86 °F) in the north and 35 °C (95 °F) in the center-south, while in the deserts it can already reach 40 °C (104 °F).
The rains are still quite frequent in the Northwest, in the northern part of the Pacific coast (see Seattle), although they are decreasing compared to the previous months. In south-central California (see San Francisco, Los Angeles), the rains are already very rare, as well as in the deserts of the southwest (see Phoenix).
Instead, in the rest of the United States, the rains are increasing compared to the previous months, due to the clash of air masses, which can generate thunderstorms.
April through June is the time when tornadoes are most frequent in east-central United States. They mainly develop along two routes: the "Tornado Alley", from South Dakota to northern Texas (north/south), and the "Dixie Alley", from Oklahoma to Ohio (southwest/northeast).

The sea is warm enough for swimming in the Gulf of Mexico, in Florida and in the southern states of the Atlantic coast up to North Carolina. Instead, to the west, on the Pacific Ocean, the sea is cold even in California.




See also: United States, the weather in April - June
The climate of United States