A blast of cold air from Canada delivered record-low temperatures to a handful of Bay Area locations Tuesday morning as the mercury dropped near or below freezing across the region. As of 6 a.m., locations setting or tying record-low daily temperatures for Feb. 20 include San Francisco airport (36, previous record 37 in 2011) and Oakland 34 (tying previous mark set in 2006), according to the National Weather Service. It is likely other records will fall, but official temperatures are not reported until the afternoon, according to the weather service.