A town site plat was filed by Jesse N. and Elizabeth Day on November 23, 1871.

The city was officially incorporated on November 10, 1881, and was named for Jesse Day.

[5] According to the United States Census Bureau, Dayton has a total area of 1.43 square miles (3.70 km2), all of it land.

Dayton has a Mediterranean climate (Köppen Csb) with hot summers (though nights are pleasantly cool) and chilly, though not severe, winters with only very moderate snowfall.

Precipitation is moderate for most of the year except for a dry period between July and September, at which time major wildfires are very common in the region due to the hot days and very low humidity.

There were 1,200 housing units at an average density of 839.2 per square mile (324.0/km2).

There were 1,181 housing units at an average density of 802.0 per square mile (310.2/km2).

[13] The library was established in 1919 as a small reading room while a women's civics club fundraised for a permanent building.

A ballot measure submitted in 2023 proposed to close the rural library district, and therefore the library itself, entirely due to the placement and availability of children's books on racial issues and LGBT topics; amid then-ongoing book banning efforts in the United States, the library would have been the first one nationwide to close over such a dispute if it succeeded, according to the American Library Association.

[13] The initiative was ruled unconstitutional in September 2023 by the Columbia County Superior Court due to its exclusion of voters in incorporated areas; the ruling blocked the initiative from appearing on the November 2023 ballot.