Temperatures hit 90 degrees Thursday as thunderheads rose over the mountains of Southern Oregon's Cascades and Siskiyous. Those conditions may prove to be an apt warning that fire season is only a week or two away.

Temperatures hit 90 degrees Thursday as thunderheads rose over the mountains of Southern Oregon's Cascades and Siskiyous. Those conditions may prove to be an apt warning that fire season is only a week or two away.

"Historically, fire season in Jackson and Josephine counties most often begins during the first two weeks of June," said Brian Ballou, spokesman for the Oregon Department of Forestry," and averages 142 days, which takes it through early October."

State forestry officials announced Thursday that fire season restrictions would begin Monday in Klamath and Lake counties.

Ballou said ODF's southwest Oregon district (Jackson and Josephine counties) should have essentially the same resources that were available last year, including 11 fire engines and crews for fire suppression in each county. There also will be a six-person fire crew at the Central Point office.

State forestry crews have primary responsibility for fires on private lands, state lands and those overseen by the U.S. Bureau of Land Management.

Ballou said decisions on some resources may not be made until the end of June, after budgets are finalized. Two state air tankers likely will be available, with one based in Medford and one in Redmond. It's not yet clear whether there will be a helicopter available at the Central Point ODF office, Ballou said.

"That's one of the vaguest points right now," he said.

"If we can get the budget lined out, we will (have a helicopter). It's sure paid for itself over the years. Sometimes the helicopter gets there ahead of the crews and can start dropping water."

Ballou said vegetation on the valley floor and south-facing slopes already has dried out enough to burn, but forest lands at higher elevations and on north- and east-facing slopes still are relatively damp.

He said the course of the weather ultimately will determine when fire season begins. Sometimes thunderstorms bring enough rain to postpone fire season; other times, there's little rain and plenty of hot weather.

These last days before fire conditions develop are a good time to take precautions to protect homes and property in fire-prone areas, he said.

"This is the time to start mowing your tall grass, or move your firewood a little farther from your home," he said.

About two-thirds of the wildfires in Oregon each year are started by people. The top cause is letting debris or waste burning get out of control.

Reach reporter Bill Kettler at 776-4492 or e-mail:bkettler@mailtribune.com