2013: Thunderstorms struck Riverside and the San Bernardino Mountains where over 1" of rain fell in 20 minutes.
Riverside was inundated with flooding of streets up to two feet deep.
Riverside City College canceled classes.
Flash floods occurred around the Perris area and along Highway 18 in the San Bernardino
Severe thunderstorm winds estimated at 70 mph hit Riverside and toppled trees there.
2010: Strong upper-level trough following a strong ridge that brought record high temperatures to the area only a few days ago dropped temperatures to record low values at many locations including the ASOS sites at Fresno, Hanford, Madera, and Merced.
2000: Thunderstorms hit the desert with 1.5" of rain in only 45 minutes and wind gusts to 61 mph at Borrego Springs.
Flash flooding resulted, with mud in homes and damaged roads in the Borrego Springs area.
Flash floods, mud and debris covered roads from Yucca Valley to Palm Springs and Oasis.
1998: Strong thunderstorms developed each day starting on this day and ending on 8.31.
1.5" of rain fell at Apple Valley, 0.77" fell in only 45 minutes at Wrightwood, and 0.68" fell in only 30 minutes at Forest Falls.
Homes and roads were flooded with four to 6' of water in Hesperia and Apple Valley.
Rock slides occurred in Mill Creek.
Roads were flooded in Sugarloaf and Forest Falls.
Flash flooding was also recorded in Hemet.
Severe thunderstorm wind gusts of 86 mph hit Sage (south of Hemet).
Gusts of 50 mph were recorded at Rialto and gusts of 45 mph hit San Marcos.
Trees and power lines were downed.
Record heat occurred near the coast as well on these same days.
Temperatures hit 114° F in Dulzura, 112° F in Yorba Linda and the Wild Animal Park, 110° F in El Cajon, Hemet and Riverside, 108° F in Ramona, 106° F in Vista and Escondido, and over 100° F in most of Orange County.
1998: The high temperature at Hawthorne was 103° F.
1974: It was 92° F in Big Bear Lake, the highest temperature on record for August.
This also occurred on 8.8.1981 and on 8.25.1985.
1972: Hurricane Hyacinth moved as far west as 125 West before recurving to the northeast.
The remnants made landfall between Los Angeles and San Diego on September 3rd with winds of 25 mph and rainfall of up to 1" in the mountains from this day to September 6th.
This tropical cyclone holds the distinction of traveling the farthest west before recurving and making landfall in Southern California.
This occurred during the El Niño of 1972-73.
Only 0.44" was measured in San Diego.
1967: Hurricane Katrina comes up the Gulf of California and comes ashore south of Yuma, AZ.
Over 2" of rain fall in southwest Arizona with lesser amounts elsewhere.
1951: A hurricane moving north northwestward just off the west coast of Baja California moved northeastward into northern Baja California and dissipated.
Moisture from this tropical cyclone resulted in rainfall of 2"-5" in the mountains and deserts starting on 8.27 and ending on this day.
Many roads were washed out in the Imperial Valley, but otherwise no major damage occurred.
This occurred during the El Niño of 1951-52.
1946: Low of 20° F at Grant Grove in Kings Canyon National Park, coldest of record at this location for the month of August.
1942: It was 36° F in Palomar Mountain, the lowest temperature on record for August.
1896: Santa Cruz received 0.73" of rain -- a record for the month.
1895: The low temperature was 54° F in San Diego, the lowest temperature on record for August.
Source: NWS San Francisco/Monterey, Hanford, Reno, Phoenix, & San Diego