3 ms·

Wow, there's some fantastic mapping of this effect from a few years ago: https://calepa.ca.gov/2015/09/16/urbanheat/ https://calepa.ca.gov/2015/09/16/urbanheat/

• njarboe 8y ago
  From the linked page: "largest effect is in southern California, where the urban heat islands blur together to form an “urban heat archipelago” with average temperatures up to 19° F higher in the Riverside-San Bernardino region at the eastern end of the basin." If it is really 19° F higher in Riverside due to urbanization(hard to believe that really), I can see why correcting historical temps for urban heat island effects is so necessary. How to do that accurately must be fiendishly difficult.