Edited 6:49 .m. Oct. 19, 2012 with forecast from National Weather Service:
The mercury is expected to plummet tonight, with a low of 56 degrees expected. Patchy fog should roll in after 11 p.m., according to the National Weather Service.
On Saturday, patchy fog should roll in before 11 a.m., then burn off, to be replaced by clouds, then sunshine, the temperature reaching a balmy 75.
Saturday night could bring rain after 11 p.m. The temperature should go down again, to 56 degrees.
On Sunday there will be a 20 percent chance of rain before 11 a.m. and the day should be cloudy throughout, the mercury topping off at 71, a little cool for Temecula.
It may begin to drizzle Sunday after 11 p.m. Sunday, the NWS reported.
Weather report by John C. Toman, meteorologist with weathercurrents.com
Cooler weather will continue into the middle of next week in the Temecula Valley and the region.
An extensive low pressure system is deepening over the west coast. Going into the weekend, expect increasing marine layer and clouds, with drizzle possible Sunday and Monday mornings. Afternoon temperatures are predicted to settle in the lower 70's.
Next week, a weak front could lead to some light rain Tuesday and Wednesday. Clearer skies, a warming trend and weak offshore flow should follow.
Today: Morning low clouds and fog, becoming mostly sunny. Warm. Northeast wind becoming south 15 to 20 mph, high near 81 degrees; tonight: partly cloudy, then low clouds and patchy fog developing. South wind 15 to 20 mph in the evening, low around 60 degrees.
Saturday: morning low clouds and fog, becoming partly sunny. Southwest wind 10 to 20 mph, high of about 75 degrees; Saturday night: mostly cloudy, then low clouds and drizzle developing, low near 59 degrees.
Sunday: morning low clouds and drizzle, becoming partly sunny, high around 70 degrees; Sunday night: partly cloudy, then low clouds and drizzle developing, low of about 56 degrees.