In winter (December – April) the northern states are the coldest, experiencing bitter, freezing temperatures. Low temperatures in January and February are made slightly warmer by the Chinook winds originating from the Rocky Mountains. The southern states, known as the ‘sunbelt’ are quite the opposite, with temperatures rarely falling below freezing.
Summers (June - September) are hot in the US but for New England, Oregon and Washington which tend to be rainier and less predictable. The Pacific Northwest states are generally temperate while the south, east coast and Midwest are more humid. Heat waves are common in the Southwest.
Spring and autumn are generally mild, warm and sunny with the exception of some wet areas, the Pacific Northwest in particular.
Tornado season arrives in the Midwest between April and June, and hurricanes are common in early summer along the southern East Coast and Gulf of Mexico coast - TV and radio will broadcast warnings for both, but the chances of encountering one on a short visit are remote.