Early spring usually does not see as much rain as winter months do, but it still belongs to the wet season. A variety of flowers and trees start blooming in March. Besides low tides work favourably for adventurous explorers willing to see the remnants of shipwrecks that are numerous in treacherous waters of notorious San Francisco Bay.
April is the month when San Francisco is found abundant with spring blooms. This is actually a transition period between wet and dry season, when the weather is particularly amiable: nearly cloudless, neither too moist, nor too dry, and with cool Pacific sea breezes being replaced by dry offshore winds.
May marks the true beginning of the dry season in San Francisco which lasts through September. This is one of the best periods to visit the city, as it is pleasantly warm, dry, and what is also important—entirely cloudless, for it is too late for heavy winter clouds, as well as still early for summer stratus and fogs.