The San Francisco Bay area can take a load off. There are four months left in what meteorologists call the “water year,” but already the city of ferryboats and suspension bridges has received more rain than in an entire normal year. Overachievers. We weather nerds made up the water year because the rainy season tends to be winter, which spans two calendar years. Shifting the water year by six months means we can look back at the year and see what a full winter was like, instead of portions of two different winters.