Amid drought, state breaks another record for temperature

This summer is not yet halfway over, but already the record book has been reset.

California has posted a record high average temperature during the first six months of this year, exacerbating a prolonged drought and sending North Coast residents flocking to swimming pools and ice cream shops.

Wildland firefighters, unable to find relief while battling more than 3,600 blazes, have suffered life-threatening heat-related illnesses that sometimes required helicopter evacuation.

“It’s serious business,” Cal Fire Battalion Chief Scott McLean said, noting that dehydration takes a toll on personnel in almost every major fire.

The hot weather also has further depleted the state’s reservoirs, boosting public water consumption as well as natural evaporation, which equals the annual draw from Lake Sonoma - the main Russian River reservoir - by a city of 53,000.

California’s average temperature from January through June was 58 degrees, nearly 5 degrees above the 20th-century average and breaking the previous record for the six-month period, set in 1934, by 1 degree, the National Climatic Data Center said.

“We haven’t seen a jump that large in California before,” said Jake Crouch, a climate scientist with the center, part of the National Oceanographic and Atmospheric Administration.

With California expected to share in the hotter-than-average weather forecast for some western states through October, a yearlong temperature record likely will be set, he said.

More than 80 percent of the state, in a band stretching from Siskiyou County south to Orange County, is in extreme drought, with reservoirs dropping, wildfires erupting, economic losses in the billions of dollars and rain, at best, about three months away. Experts are suggesting that California’s three-year drought is the most intense in more than 100 years and will continue through 2015.

This year’s heat record is part of a long-term trend of increases on the order of 0.2 degrees per decade since the late 1800s, said Daniel Swain, a Stanford University environmental science graduate student who writes the California Weather Blog.

Three cities - Fresno, Sacramento and San Francisco - posted the warmest six months ever, beating their 30-year averages by 3 to 5 degrees, the data center said.

Santa Rosa’s average January to June temperature this year was 59.3 degrees, up 2.4 degrees over the 30-year average, according to The Press Democrat’s records.

“We’ve definitely had a warm start to the year,” said Don Hicks, the Santa Rosa city recreation supervisor in charge of the Finley Aquatic Center and Ridgway Swim Center. On July 25, when the mercury hit 98 degrees, both facilities had people lined up at the door, forced to wait because the pools were at capacity.

That’s happened several times this year, and on some hot days a line forms an hour before opening at the Ridgway pool, popular with youngsters for its water slide and play features, Hicks said.

The influx has boosted pool revenue to record levels, and Hicks said he’s hoping for a heat wave between the end of the Sonoma County Fair and the start of school. During the 16-day fair, pool attendance does not spike no matter how hot it gets, he said.

At Screamin’ Mimi’s Ice Cream in downtown Sebastopol, sales this year are up from 5 percent to 10 percent each month, with lines out the door on the busiest days, co-owner Maraline Olson said. January and February were good months, and May was “exceptional,” she said.

“We can give you a daily weather report based on sales,” Olson said. The only drawback to a heat-based surge in scooping ice cream is her small shop’s production limit of 120 gallons per day.

Heat is one of the three necessary ingredients for a fire, along with fuel and oxygen, and the fuel in California’s wildlands - grass, brush and trees - is now as dry as it typically is in October, Battalion Chief McLean said. Cal Fire, with staffing boosted to 7,000, including an extra 300 people hired due to the drought, already has responded to more than 3,600 blazes statewide covering more than 40,000 acres - both well above five-year averages.

Dehydration is a constant concern for fire commanders, McLean said. When firefighters are carrying heavy loads over steep terrain, dehydration can lead to life-threatening heat stroke “in a heartbeat,” he said.

When it happens far from a road, Cal Fire may have to divert a firefighting helicopter to ferry the victim to an ambulance, airport or hospital, McLean said.

Crews mopping up in a fire-?blackened area experience temperatures 5 degrees hotter than the ambient conditions, he said.

Amid Gov. Jerry Brown’s call for Californians to cut water use by 20 percent, most of the state’s major reservoirs are below 50 percent of capacity, with giants like Lake Shasta (37 percent) and Lake Oroville (38 percent) considerably lower. Getting people to curb water consumption is proving difficult, but nothing stops evaporation, which increases with warmer air temperature, said Jay Jasperse, Sonoma County Water Agency’s chief engineer.

Lake Sonoma, the region’s major reservoir, is in better shape than many with about two-thirds of its water-supply pool stored behind the 319-foot Warm Springs Dam near Healdsburg.

In a typical year, evaporation draws 7,465 acre-feet of water from the reservoir, just 3 percent of its water-supply pool but equal to a year’s consumption by 53,000 people. (Lake Mendocino, the other large local reservoir, on the upper Russian River, is currently at about 35 percent capacity.)

Plants, just like people, consume more water when it’s hot through a process called evapotranspiration, drawing water from the soil, Jasperse said.

California’s topsoil and subsoil moisture reserves are nearly depleted after three years of drought, the U.S. Drought Monitor noted this week.

The outlook isn’t entirely bleak in Sonoma County, where grape growers have enjoyed ideal weather, said Duff Bevill, who manages 1,000 acres of vineyards in the Alexander, Dry Creek and Russian River valleys. Warm, dry weather in the spring got the growing season off to an early start, leading to an early harvest that began this week.

“The fruit’s beautiful out there,” Bevill said, noting that the weather has been moderate, minus the heat spikes that can harm grapes. The mercury has reached 90 or higher only 20 days this year, and hit 100 just once, on June 8, according to Press Democrat records.

The state’s record heat through June is no surprise, Bevill said, recalling the unusually sunny spring that failed to make up for an arid winter.

“It makes sense that the temperature was warmer,” Bevill said.

You can reach Staff Writer Guy Kovner at 521-5457 or guy.kovner@pressdemocrat.com.