The National Weather Service has issued a freeze warning for Marin County interior valleys tonight.
Much of urban Sausalito has extra natural defenses against borderline freezing temperatures and was not named as an especially vulnerable area in the alert, but if the thermometer starts dipping down into the high 20’s more homes will have garden damage. San Rafael and points north as well as West Marin were called out as especially vulnerable.
If you’re close to the Bay the water actually warms the air at night, making your area less likely to freeze unless we get extreme cold. Our floating homes community laughs at all but the most dire freeze warnings.
If you live in a Sausalito valley where the air naturally flows downward to the Bay you’re also warmer than average. At night cooler air flows down towards sea level and warmer air rises, so the upper reaches of our valleys are warmer and the bottom areas are colder. Bayside spots at the foot of our valleys have warm air coming one way from the Bay and cold air drifting down from up the hill.
The most dangerous spots subject to freezing when the temperature gets down to 32 in the wee hours of the morning:
- Near the top of Wolfback Ricdge, Clyde Ridge and other peaks in the Marin Headlands
- Interior valleys of the Marin Headlands (Rodeo Valley is less likely to freeze since it naturally channels cold air down to the Pacific Ocean)
- Areas near sea level but not close to the Bay
- Nooks and crannies in the valleys where the cold air gets caught and can’t escape down the hill
If you live in a spot where plants can be damaged by frost, here’s an article on how to protect them. Some of these measures are for colder climates, but others apply here and are not always well-known.
The good news for folks who moved to Sausalito from cold weather states: we almost never have to worry about frozen pipes here.