The Sierra Nevada in California was so bereft of snow in December that skiers and farmers alike worried that a disappointing winter was sure to give way to a drought-ridden spring and summer.

Then came a deluge in subsequent months, enough to bring the state back to a normal snowfall level and then some, state leaders announced on Tuesday during the most crucial snow measurement of the year. The snowpack in the Sierra Nevada on Tuesday stood at 110 percent of average for early April, an encouraging sign that the state would have plenty of water — at least, in the months ahead.

“Average is awesome,” Karla Nemeth, director of the state’s Department of Water Resources, said from a field blanketed in white and ringed by evergreen trees near the headwaters of the south fork of the American River near Lake Tahoe.

The store of snow sitting atop the Sierra Nevada, the state’s biggest mountain range, is by far the largest and most important reservoir in California. In the dry months to come, the snow will melt and course downhill, replenishing scarce water supplies.

For the second straight year, Californians navigated flood watches and blizzard warnings in February and March, as a string of big storms caused mudslides and snarled traffic, particularly in Southern California. This past weekend, a storm once again caused the collapse of a section of Highway 1 in the Big Sur area.

But Gov. Gavin Newsom warned residents not to grow too comfortable with heavy precipitation and pointed to the month-to-month swings as indicative of how California’s weather patterns had become ever more erratic.

“Extremes are becoming the new reality,” Mr. Newsom said. “One weather system or one weather year doesn’t necessarily make a trend.”

The beginning of April is a particularly important moment for gauging California’s water status in the increasingly wide swings between deluge and drought. It is the time of year when residents expect storms to begin to disappear for months.

A year ago, after a procession of atmospheric rivers wreaked havoc on unprepared communities from the coast to the mountains, the same spot where Mr. Newsom and water officials stood Tuesday was covered in more than 10 feet of snow. Only half that amount is there this year.

But state leaders were nonetheless cheerful. Consider this: Nine years ago, Gov. Jerry Brown stood in that very same meadow “unable to find a shred of snow,” Wade Crowfoot, secretary of California’s natural resources agency, said.

In the years that followed, the state would become even drier. Millions of acres of tinder-dry vegetation burned in 2020. Heading into last year, one of California’s wettest years on record, six million Californians were under water rationing rules, Mr. Crowfoot said, “and we were planning for a whole lot more.”

Mr. Newsom emphasized that the state still had to prepare for future droughts. California’s water system, he said, “was designed for a world that no longer exists.” Climate models show that the American West will have to contend with less and less water as temperatures rise to dangerous levels during the summer.

Mr. Newsom said the state’s leaders weren’t letting up on projects aimed at capturing and storing water when it is available. He said the state has spent $9 billion on water projects just in the last three years.

“We recognize our responsibility,” he said. “There’s nothing normal about this average year.”