The low pressure system made landfall late Wednesday into early Thursday, dropping temperatures 5 to 10 degrees below normal along the coast and 10 to 20 degrees below normal inland.
The National Weather Service reported a new record temperature was set on Palomar Mountain Thursday. The daytime high was the coldest it's ever been at 50 degrees -- two degrees cooler than the previous record low high for an October 11, which was set in 2000.
The storm also dropped a record .44 inches of rain in Oceanside, breaking the previous rainfall high of .35 inches for the same date in 1987.
Though mostly light to moderate showers are expected Friday, brief heavy downpours are possible, according to a NWS advisory.
The agency urged motorists to slow down on wet roads.
The weekend is expected to bring a gradual warming trend along with fair weather, NWS meteorologist Tina Stall said.