Last week’s hot spell only enhanced the chances of wildfires this fall.
On Thursday, Sept. 5, the low nighttime temperature in Idyllwild was 64
degrees tying the 2019 record low. Two days later, the low nighttime
temperature was 63 degrees which tied the 2023 record for that date.

Cal Fire’s Predictive Services unit had already issued its September
wildfire outlook report prior to the weekend weather.

“There is a slight to moderate tilt in the odds for above normal fire
potential towards the Western Mountains, Eastern Mountains, Southern
Mountains and South Coast for October and November,” they wrote on Aug.
31.

Although temperatures were slightly below normal in August,
precipitation in Southern California has fallen, too. “Most of the area
also saw less than 50% of the average August precipitation.” Predictive
Services reported. “There are localized areas of positive precipitation
anomalies due to intermittent monsoon moisture resulting in slow moving
thunderstorms; however, most of the region remained dry.”

“In 2024, the monsoon was a near no-show on its western flank. Monsoon
2024 summer precipitation was well below average in all California
regions that usually see some summer thunderstorms,” wrote Daniel Swain,
meteorologist and climate scientist at the Institute of the Environment
and Sustainability at the University of California, Los Angeles on his
“Weather West” website.

Consequently, drought conditions are returning to California, including
northwest Riverside County, along with lower fuel moisture readings,
which are spreading throughout Southern California.

However, they generally remain high on the San Jacinto region, according
to Cal Fire. The latest data show normal reading in the Las Padres
National Forest, but this a drop from relatively high moisture levels in
the spring.

On Sept. 3, Cal Fire added this comment, “The combination of heavy
herbaceous fuels with seasonably available dead wood and live fuels
results in a highly flammable fire environment where rapid fire growth
has been observed and is expected to continue for initial attack fires.”

Already, wildfire incidents in 2024 have significantly exceeded 2023.
Through Sept. 3, Cal Fire has reported 5,755 wildfires greater than 10
acres, slightly more than the 5-year average of 5,602. These fires have
burned a total of nearly 840,000 acres. For the same period in 2023,
4,787 fires had burned only 255,000 acres. The five-year average of
acres burned in the same period is 722,000, about 14 % less than the
2024 total thus far.

Swain continues to see the possibility of a major surge in wildfire
activity this fall. “I think there’s a pretty good chance of a robust
‘second season’ from a wildfire perspective this year (following the
initial July surge, there may well be another in Sep into Oct in some
regions),” he stated.