There's a cool springtime feel to the first days of summer, but the Bay Area can expect just a dampening from the rare June rain.

"We've had morning dew that's stronger than this," said Tom Hicks of Silva Ranches Feed Store in San Martin. "You could spit more water than we got," he said.

A moisture-laden jet stream usually parks itself far north of California in the summer, greening Portland and leaving us as dry as kindling.

Instead, we've been blanketed by low clouds, prompting beachgoers to reach for sweaters instead of sunscreen.

"The jet stream sagged southward," explained Kevin Baker of the National Weather Service in Monterey. "This is kind of an unusual event, more typical of what you see in wintertime."

Modest showers are expected Tuesday, with up to a quarter of an inch falling in San Jose and a half-inch in Oakland.

Because hay can mildew when wet, Monday was a busy day at Tilton Ranch in Morgan Hill, where Janet Burback and her family rushed to get 600 bales of oat hay into the barn. They depend on the hay to feed their Hereford-Shorthorn cattle all summer -- and because so little rain fell this winter, supplies are lean, she said.

"We were scrambling to get it in," she said. "It's vital. It was already cut, baled and stacked, but we had to load it on trucks and get it under cover."

Sonoma's Hawkeye Mountain received the most rain, with 0.21 inches over 24 hours, and 0.20 inches at Contra Costa's Los Medanos College with smaller amounts falling at higher elevations including Contra Costa's Black Diamond Mines Regional Preserve and Mount Diablo, and Santa Clara County's Mount Hamilton and Mount Umunhum.

Farther inland, high humidity helped firefighters contain flames in the Mariposa wildfire that has burned about three square miles near the main route into Yosemite National Park, said Daniel Berland of Cal Fire.

While uncommon, it's not unusual, said meteorologist Jan Null of Golden Gate Weather Services.

The month of June sees rain two out of every three years, according to his calculations. In the past 164 seasons since 1850, there has been rain in June 107 times; on average, the month averages 1.5 days of rain. The second wettest June on record was just two years ago, in 2011, when a startling 2 inches of precipitation caused spinouts and fender benders.

But summertime will return by the weekend, when the high pressure system pushes storms north again.

Temperatures are expected to soar by Monday, reaching 90 degrees in San Jose and 96 in Livermore.

Contact Lisa M. Krieger at 650-492-4098.