Even though the weather has been warm the past few days, it hasn’t changed this fact: The summer that just ended was one of the coolest in recent years.
There have only been nine days over 100 degrees since June, said Johnnie Powell, weather forecaster for The National Weather Service. The temperatures were recorded at the Stockton Metropolitan Airport.
“There were no heat waves at all,” he said. “It just happens like that some summers.”
When measured by number of days over 100 degrees, this summer was the mildest since 1997, when there were 12 days over 100 degrees.
An average summer has 20 to 22 days over 100 degrees between June and September, said Ken Clark, a meteorologist for AccuWeather, a private forecasting service.
The moderate temperatures, coupled with showers throughout the spring, set harvest back for virtually every crop, said Bruce Blodgett, executive director for the San Joaquin Farm Bureau Federation.
“The one thing I keep hearing is that things are delayed,” said Blodgett. “We will be harvesting until deeper into the fall, but it’s impossible to say what the full impact will be until the harvest is in.”
Some winegrape growers literally stopped their harvests in recent weeks due to the slow progress in crop production, said Blodgett.
“We had people going in with full crews and had to slam on the brakes and stop and wait for the grapes to catch up,” he said.
The nature of farming means being at the mercy of the weather, he said, and added there is little growers can do but take a wait-and-see approach to harvest. There are no expectations for rain in the near future according to weather forecasts, but Blodgett said the potential for showers could pose a problem if harvest stretches late into the year.
Rain late in the year can cause rotting in developed crops like Zinfandel grapes and can make fields muddy and difficult for machines to navigate.
The city of Lodi also noticed some effects from the cooler summer. Lodi Electric Utility users didn’t turn on their air conditioners as much as last year during the cool spring, said Jeff Hood, spokesperson for the city of Lodi.
The amount of kilowatt hours of energy used by city of Lodi customers was down 4 percent from last year, Hood said.
The figures are from fiscal year 2009-2010, so data from July and August is unavailable. However, Hood said the cool summer will likely be reflected when the most recent months’ data is released.
“I’m not expecting a big increase,” he said.
Revenues at Lodi Lake were also down for the previous fiscal year. However, youth sports activity was up at public parks and workers were better able to maintain the parks because the sun wasn’t scorching and killing the grass, Hood said.
Clark believes a variety of factors are responsible for the cooler summer.
Typically high-pressure systems build across Arizona and Nevada and bring hot weather to California; however, the higher pressure systems occurred farther east than usual this year, Clark said.
“We had more areas of low pressure on the West Coast that brought in cooler marine air,” he said.
Water temperatures in the ocean are also running much colder than normal and could have been a factor in the moderate summer, he said.
Water temperatures on the West Coast — from the Pacific Northwest to Baja California — are running between 2 and 4 degrees Celsius below average, he said.
Clark wasn’t sure what accounted for the cooler water temperatures but said upwelling, when currents bring colder and deeper water to the surface, was likely a major factor.
The cooler water temperature also played a part in the Central Valley’s cooler summer, he said.
“It had a hand in it,” he said.
Whatever the reasons for the cooler summer, Blodgett said he is most concerned with wrapping up harvest and not having crops being exposed to the elements for a prolonged period.
“Everybody wants to be done,” he said.
While he can’t control the weather, Blodgett said he wanted conditions that would be friendly for farmers in the coming weeks.
“We need a long, dry fall followed by a heavy, wet winter,” he said.
Contact reporter Jordan Guinn at firstname.lastname@example.org.