California’s climate threats could soon be jumping from wildfires and blackouts to floods and mudslides as the wet season kicks into gear.

About half the water that falls in the state in any given year does so in the 90 days between Dec. 1 and the end of February. Too much rain has at times meant catastrophic floods and dangerous mudslides. Too little threatens agriculture with drought, and potentially creates a tinderbox effect in the year ahead.