Rain. Rain. Rain. The winters in the San Francisco Bay can be really wet. While winter is nearly over, the last few weeks of the wet season can be hard to maintain. Yosemite is socked in. Mortar Rock can be hit or miss. The slopers at Castle might be drenched. The best way to beat the winter doldrums can be to head out to the crags anyway. Driving over to the east side of the Sierra, to the boulders of Bishop, can almost guarantee dry weather.
Often times, a hike through the redwoods of Castle can be a great way to get out and exercise. Even in a light rain, the Santa Cruz Mountains are beautiful.
Another awesome option is to head out to the nearest Touchstone gyms, where it never rains!