Cloudy Skies Will Hide Last of Summer Sun

San Diegans hoping to celebrate summer’s last hurrah won’t get any help from the weather this weekend, as unseasonably cool temperatures, partly cloudy skies and near-freezing overnight lows are all a part of the forecast.

Fall officially begins at 1 a.m. Tuesday, but for the last weekend of summer, temperatures will be four to five degrees below normal, and the typical night and morning low clouds will give way to only partial afternoon clearing. There is a slight chance of light drizzle during the morning hours in the coastal areas.

“Last weekend we saw a lot of clouds and cool temperatures, and I expect we’ll see a repeat this weekend,” National Weather Service forecaster Wilbur Shigehara said. “The last couple of days, temperatures have been hovering right around seasonal, but they will cool off again by the weekend.”

The early fall-like weather is the result of a low-pressure system that has hovered over the entire West Coast since last weekend, Shigehara said.

“This kind of low-pressure system is very rare for this time of year,” he said. “It is preventing any chance of a Santa Ana condition, with its hot winds and warm temperatures, from developing like it usually does during September.”

Shigehara said two sources of rain that had been approaching the area slowly are now stalled and not expected to reach San Diego.

“The northern rain source should only reach as far south as Central California, and the southern rain storm is stalled halfway between here and Hawaii,” Shigehara said. “While there will be some clouds milling around, we shouldn’t see any rain activity.”

The high at Lindbergh Field Thursday was 74 degrees; the average for that date is 76. The high over the weekend should reach 71 or 72, Shigehara said.

Highs at the beaches struggled to reach 70 Thursday; they should reach between 67 and 69 over the weekend. The ocean temperature will remain around 66 degrees, and the surf will be two to three feet.

“We’ve been getting phone calls from surfers asking when the surf is going to pick up like it has in Septembers past,” Shigehara said. “The surf has been very small because we haven’t had the hurricanes we usually get to the south of us, which have a tendency to kick up the waves.”

Temperatures in the inland valleys should be between 73 and 79, with nighttime lows between 57 and 62.

“It should be pleasantly cool overnight,” Shigehara said. “Two years ago we had the hottest September since 1872, and while this is not the coolest September we’ve ever had, it is quite a contrast to 1984.”

Desert highs between 86 and 92 are expected, with lows between 62 and 67. Mountain highs will reach the low 60s, with overnight lows dipping to a near-freezing 35 degrees.

“Some of the mountains in Northern California have snow over the 7,000-feet level,” Shigehara said. “However, our local mountains won’t be seeing any snow activity for a little while yet.”