1999: The "Williams Fire" 9 miles NNE of Lodgepole in Tulare County was caused by lightning strikes on 9/18 but was allowed to burn and managed as a "resource" burn through October (although truncated for report purposes in September).
It burned a total of 500 acres.
No fatalities or structures lost.
1997: A hiker died of hypothermia after being caught in the a snowstorm in Fresno County portion of the Southern Sierra Nevada Mountains.
The base camp was at the 12,000 foot elevation west of Bishop (Inyo County).
The hiker and a friend were unprepared for winter-like weather.
Their sleeping bags and gear got wet in the storm.
The hiker died in the Inyo County hospital at 1:30 PM PST on Friday the 19th.
1985: A tornado was reported around the north shore of the Salton Sea.
1985: During a severe thunderstorm, a funnel cloud was reported over the central portion of Yuma, AZ.
Strong winds produced damage to some homes and at least 1 business.
Winds were strong enough to force a 2x4 through a stucco wall.
1984: Fresno’s warmest low temperature on record for September is set, 78°.
1982: The remnants of Hurricane Norman tracked northeastward across northern Baja California into Arizona with scattered rainfall amounts up to 1" in the southern mountains and deserts on 9.17 and on this day.
This occurred during the strong El Niño of 1982-83.
1966: There was darkness at noon in Las Vegas, NV, and surrounding areas when heavy rains and high winds ripped through town, causing extensive damage and injuring several people.
Hardest hit by the storm were three trailer parks on the east side of town. Residents of Riviera Vegas Mobile Home Park for adults and the adjoining family park on Palm Avenue were literally picking up the pieces of two trailers which were "disintegrated" in the wind.
Miracle Mile Trailer Park on Boulder Highway reported two trailers blown over, a roof blown away, and a car demolished.
1963: Tropical Storm Jennifer-Katherine made landfall in northern Baja California (the storm has two names because forecasters thought the storm had dissipated, but later reformed).
The storm brought heavy rains to the region over a 3-day period centered on this day.
Up to 6.5" of rain fell in the mountains, 3.86" fell in San Bernardino, 3.66" in Victorville, 3.29" in Riverside,1.44" in Palm Springs,and 1" in San Diego.
Disastrous flooding and erosion hit parts of San Bernardino.
1959: Woodfords, CA (Alpine Co.), recorded 2.60" of precipitation.
1959: Ben Lomond received 8.35" of rain and San Jose received 2" of rain.
1939: A heat wave that started on this day and ended on 9.22 preceded the arrival of a tropical storm called “El Cordonazo.”
High temperature records of more than 95° occurred at San Diego each day, with the highest temperature reaching 106° on 9.21.
1929: A tropical cyclone moved north northwest just off the west coast of Baja California, dissipating off the coast of northern Baja California.
Rainfall of up to 4" occurred in the southern mountains and deserts of Southern California on this day.
1924: It was 38° F in Escondido, the lowest temperature on record for September.
Source: NWS San Francisco/Monterey, Hanford, Las Vegas, Reno, Phoenix, & San Diego