Federal law in the United States requires that the presidential election (and others) be held every four years on the first Tuesday after the first Monday in November.
In today's society, it may seem a little odd that we do that, but during the 1800s, it made perfect sense.
It wasn't until the mid 1800's that Congress standardized a day for Elections. Before that, the date for the election of the president would be set by the individual states. Those various election days, however, almost always fell in November.
Holding elections in November made good sense back then for several reasons. The harvest would have been concluded, and the harshest winter weather would not have arrived yet, which was a consideration for those who had to travel long distances to a polling place by horse and buggy.