Related: Freezing San Franciscans Prohibited From Building Wood Fires Wednesday

Some Bay Area cities saw record low temperatures today as a cold spell held its grip on the region, a National Weather Service forecaster said.

In the early morning hours, San Rafael had a low of 28 degrees, tying the city’s previous record for the date set in 1972. The North Bay had some of the lowest recorded temperatures in general, forecaster Duane Dykema said, with many areas reaching the low-20s.

In the South Bay, Moffett Field tied a record low of 31 degrees, which was set in 1994. The city of Santa Cruz also met its record low of 27 degrees for the date. That temperature was also recorded in 1978.

Salinas recorded a low of 29 degrees, breaking its previous record of 30 degrees set in 1980.

Dykema said today and Wednesday will likely be the coldest days of the week.

The National Weather Service has issued a frost advisory which will be in effect from midnight today through 9 a.m. Wednesday for several parts of the Bay Area, including the Point Reyes National Seashore, San Francisco Bay Shoreline, San Francisco Peninsula Coast, and Northern and Southern Monterey Bay areas.

Additionally, a freeze warning will be in effect for those hours for North Bay interior valleys and mountains, East Bay interior valleys, the Santa Clara Valley, the Northern Salinas Valley and Carmel Valley.

Dykema cautioned motorists to “keep a watch out for slippery patches on overpasses and some mountain roads.”

Although this morning’s cold weather didn’t cause widespread delays at San Francisco International Airport, duty manager Jeff Littlefield said some airlines experienced delays because a few aircraft had to be “de-iced,” which he said is “very rare.”

Airport officials anticipate normal operations for Wednesday morning, Littlefield said.

The Bay Area Air Quality Management District has issued its second Spare the Air alert of the season for Wednesday, which means that burning wood, manufactured fire logs or any other solid fuel is not allowed.

The ban applies to both indoor and outdoor fires in fireplaces, woodstoves, fire pits or other wood-burning spaces.

A combination of cold temperatures and light winds will trap any smoke in the air, creating a layer of pollution over the Bay Area, said Jack Broadbent, the air district’s executive officer.

Dykema said temperatures are expected to increase later this week, and that the region will likely be hit by rain on Thursday.

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