For the past three wet seasons, California has been far better off compared the years prior to 2017, as the historic statewide drought impacted both humans and wildlife for the 5 year stretch. Now, after the generally above-average 2018-2019 winter, there’s plenty of water to support plant life which in turn supports smaller animals. Those smaller animals include small rodents – food for adult rattlesnakes. The additional ground-level ability for life also feeds and supports lizards better, which equates to young rattlesnake food.
Right now, it’s early April and continued unsettled weather is anticipated through at least mid-April. This is another thing that hasn’t happened in several years. Typically, California’s grasses begin their die-off due to precipitation cutting off and temperatures beginning to skyrocket. On average, northern & north-central California’s natural grasses (which are actually invasive for the most part, brought here by European settlers) brown out throughout May, after storms shut off in March or April.

A longer wet season means that plants & naturally occurring grasses that feed rodents will be supported a little longer into the active snake season, feeding key prey species for snakes longer into the season. These impacts, while likely relatively small in scale unless an extreme weather event impacts California this Spring, is another chip on snakes’ shoulder this season.
That said, during drought years snake are still successful in hunting, however. Otherwise, snakes would’ve died off long ago. How do they adapt? Travel distances over a summer and hunting spots. Plenty of people will say that drought years lead to more snake encounters in areas where people also reside. This simply isn’t the case. If anything, drought lowers the amount of travel they do and wait for an opportunity prey item to run by. Otherwise, they’d be burning up their energy reserves and water content without payoff (a meal).

During years where drought isn’t an issue, there’s likely (at least) a little more prey available, leading to better hunting and generally healthier snakes. More food also means more energy, and more energy to burn equates to more movement potential, with less worry of energy reserve burn-off. More movement doesn’t have to mean encounters with people, but in some cases it’ll happen as snakes travel to key locations and unknowingly traverse through human inhabited areas.
So, the takeaway here is that compared to a drought year, snakes should have better hunting opportunities this year due to a good water year supporting prey items. Thus, more food means more energy – and more energy means more potential movement. Compared to a drought year, wet years likely have slightly higher odds at increased snake encounters as snakes utilize the extra energy to explore and find even better hunting spots. This doesn’t mean there’s more rattlesnakes, it simply means they may be a little more mobile.
Snake encounters don’t have to be looked at negatively either. A snake stopping by means it likely has stopped by before (especially if it’s an adult) – without you even noticing. Chances are, it’s taken quite a few rodents off your hands you probably don’t want scurrying around either.