July is the seventh month of the year in the Julian and Gregorian calendars and is the fourth of seven months to have a length of 31 days. It was named by the Roman Senate in honour of Roman general Julius Caesar in 44 B.C., it being the month of his birth. Before then it was called Quintilis, being the fifth month of the calendar that started with March.

It is on average the warmest month in most of the Northern Hemisphere, where it is the second month of summer, and the coldest month in much of the Southern Hemisphere, where it is the second month of winter. The second half of the year commences in July. In the Southern Hemisphere, July is the seasonal equivalent of January in the Northern hemisphere.

"Dog days" are considered to begin in early July in the Northern Hemisphere, when the hot sultry weather of summer usually starts. Spring lambs born in late winter or early spring are usually sold before 1 July.