By Reginald Stanley. Posted September 1, 2020, 11:23 PM.

August 2020 finished as one of the warmest months in at least 20 years across portions of inland Southern California, largely due to an intense, protracted heat wave that lasted most of the month - and yet another bout of extended heat is in store for September as well.

Another strong ridge of high pressure is forecast to establish itself over the southwest beginning Friday, peaking over the weekend but continuing well into the following week. The National Weather Service has announced an Excessive Heat Watch for all of Southern California beginning Friday morning, lasting through Monday evening. All areas in the region will be affected by the excessive heat, except for the mountains over 5,000 feet above sea level. Saturday and Sunday will both see dangerous levels of heat, as well as elevated fire conditions. Triple-digit high temperatures are expected across most inland valleys every day starting this weekend through late next week. Chances for notable monsoonal moisture incursions will remain low throughout the period.

The coming heat spell follows a brief reprieve that began at the very end of August, which itself had come after a long, extended heat spell. In Temecula, where reliable records date back to August 1999, the month of August in 2020 was the second-warmest such month recorded there, after August 2012 in first place. August was also the fourth-warmest month recorded in Temecula, where July 2018 fell in third place and July 2006 in first place (August 2012 was second). Other, newer WeatherCurrents stations recorded similar trends, including Murrieta. In both Lake Elsinore and Hemet, July 2018 remained as the warmest month since records began at those stations in 2005 and 2003, respectively. The heat was not nearly as pronounced in Simi Valley to the northwest.