Unlike most parts of Southern California, Northern California and the Delta region do experience seasonal changes in weather conditions. As early as March, the rain and fog will stop, and fresh grass will pop up in a day or two.
Flowers start to bloom and all the species of birds found in the Delta become more active.
March can still be somewhat wet, but the days get warmer. Can be in the mid-60's or low 70's. Early spring we can still have occasional cold nights in the high 30's but usually it is high 40's or low 50's at night. The water at this time of year is VERY cold as it is the snow run off from the Sierras. There are also logs, brush and other debris that have been pushed or fallen into the waterways upstream that float on down to the bay via the Delta.