When we say the weather has turned cold in San Diego, that usually means one thing: It's time to put on a sweater. Or maybe just a decent Chargers T-shirt. It's relative. The city rarely gets genuinely cold. And it never experiences the sort of life threatening lows that currently afflict much of the country.
There are two reasons for this. Brandt Maxwell, a forecaster at the National Weather Service, says, "We're protected to the west by the ocean. It has a much higher heat capacity than the air, so it moderates cold weather that comes from the Pacific. And we're protected to the east and the north by the mountains, which block a lot of cold air from coming here. That's not just the local mountains; air is also blocked by mountains in northern Arizona, Nevada, Utah and the Sierra Nevada. When we do get 'down slope' winds, the air heats up because it compresses."
History proves the point. The coldest day in San Diego history occurred on Jan. 7, 1913, when the temperature dropped to 25 degrees. By comparison, Chicago today recorded a low of minus 15 degrees. The prior record for Jan. 6th was minus 14, set in 1988.
It was miserable all over. At 3:45 p.m., the temperature in St. Paul, Minn. was minus 13. With the wind chill, it felt like minus 37. At about the same moment, it was 71 in San Diego. With 7 knot winds the wind chill was, well, 71.
"It might feel cooler than 71 to a skinny guy like me," said Maxwell, who grew up in Lawrence, Kansas. As he spoke, the temperature in Lawrence was 7. "That's certainly one of the reasons I don't go back this time of year."
Maxwell won't go through the winter unscathed. He's forecasting sprinkles for Thursday. You've been warned.
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