By TIM HEARDEN

Capital Press

SACRAMENTO -- Autumn is in the air in California after October in the Sacramento Valley was ushered in by what was likely the area's last triple-digit spike of the year.

Longer-term forecasts show mostly sunny skies in Northern and Central California through October. The federal Climate Prediction Center envisions slightly warmer temperatures than normal in California's interior areas over the next month, with below-average precipitation throughout the state.

Last weekend's short heat wave, which topped out in the high 90s in most areas of the San Joaquin Valley, came as fall harvests are moving at full speed. According to the USDA's National Agricultural Statistics Service office here:

* The hot and dry weather in September has assisted the harvest of nearly all fruit crops. Raisin grapes continued to dry on the vine and on paper, while late-variety table grapes were picked and red and white winegrape harvest was in full swing.

* Valencia oranges continued to be picked and sorted because of the re-greening that occurs with summer heat. Oversized fruit was being juiced.

* Rangeland and non-irrigated pasture continued to deteriorate because of a lack of moisture, with some reports of very poor conditions in the San Joaquin Valley. Rangeland allocations in Siskiyou County were being shut down early because of drought and wildlife forage needs.

Whatever rain arrives this weekend, it likely won't be a repeat of 2011, when a one-two punch of storms in Northern California brought the normally robust nut harvests to a stop.

The first series quickened hull split in walnuts, which is usually a good thing, but the second washed many nuts off the trees and onto the muddy orchard floor.

Weather patterns during transitions between seasons are harder to predict, Rasch said. But there doesn't seem to be a lot of moisture on the horizon, he said.

"The worst-case scenario may be light rain," he said of the upcoming system, adding that he doesn't think it'll disrupt harvests. "I don't think we're going to see that from this."

September heat

Here are the average temperatures for selected California cities in September, according to the National Weather Service:

Redding: High 95.8 degrees, low 57.2 degrees

Sacramento: High 90.4 degrees, low 55.3 degrees

Stockton: High 90.9 degrees, low 55 degrees

Modesto: High 91 degrees, low 59.5 degrees

Salinas: High 71.4 degrees, low 53.8 degrees

Fresno: High 96.8 degrees, low 65.9 degrees