All four seasons are represented in most of the County. Precipitation varies according to area with mountainous and hilly areas receiving more than the desert areas. Along the Great Salt Lake there is usually only about four inches per year, while the higher reaches of the Wasatch receive over 30 inches per year. The central area, which is the most concentrated agricultural area, generally receives about 14 to 16 inches per year. Most of this precipitation comes in the winter season in the form of snow.
Frosts are fairly common in the spring and fall.
Box Elder County was incorporated in 1869, well before Utah became a state 27 years later. It was created in 1856 by the territorial legislature from portions of Weber County. In 1880, the borders were again re-aligned. At this time the waters and islands of the Great Salt Lake were divided between Salt Lake, Davis, Weber, Tooele and Box Elder Counties. As with other northern Utah county areas, the first visitors to the region were fur trappers and explorers.