Hayfork is a census-designated place (CDP) in Trinity County, California, United States.

[2] It was subsequently named Kingbury, then Haytown, and finally Hayfork after the nearby creek.

[3][4] In 1921 the first Trinity County Fair was held with the Governor at the time William Stephens [1] Hayfork is located at 40°34′17″N 123°8′48″W / 40.57139°N 123.14667°W / 40.57139; -123.14667 (40.571406, -123.146619) at an elevation of 2310 feet.

This region experiences warm (but not hot) and dry summers, with no average monthly temperatures above 71.6 °F or 22 °C.

[6] Hayfork experiences extreme diurnal temperature variation in summer, while in winter the diurnals are wide enough to cause significant air frosts during night.

Atypical for an area with such hot summertime temperatures and mild winters, frost usually occurs from mid September to early June, and frosts throughout the summer are not unheard of.

Three times every ten years the temperature drops below 0 °F or −17.8 °C, while daily maxima below 32 °F or 0 °C occur at an approximately identical frequency.

The town sees a mean of 2370.5 growing degree days with a base temperature of 50 °F or 10 °C.

There were 1,157 housing units at an average density of 7.4 per square mile (2.9/km2).

[3] In the state legislature, Hayfork is in the 2nd Senate District, represented by Democrat Mike McGuire,[15] and the 2nd Assembly District, represented by Democrat Chris Rogers.

[16] Federally, Hayfork is in California's 2nd congressional district, represented by Democrat Jared Huffman.