Five straight days of triple-digit temperatures next week — including what likely will become the hottest Rogue Valley day in 25 years — will send people scurrying for shade while pushing wildfire danger to extreme.

The National Weather Service is predicting temperatures eclipsing 100 degrees Monday through Friday, with Wednesday's forecast of 111 degrees marking the hottest day in Medford since it hit that same level June 22, 1992.

Ashland's forecast highs for Monday through Thursday are, respectively, 101, 103, 104 and 102, with Friday cooling off to a high of 95.

Tuesday's forecast high in Medford of 108 degrees and Thursday's forecast of 105 degrees would set records there for those dates and likely help create record-high low temperatures in the low 70s as well, according to the weather service.

"If our forecast comes true, we could have three new records in a row, and that's even if we're off by a couple degrees," said weather service meteorologist Ryan Sandler. "That's pretty warm around here."

It'll be warm enough to tip Rogue Valley lowlands into extreme fire danger beginning Monday on private land, Bureau of Land Management holdings and other lands protected by the Oregon Department of Forestry.

Grass, brush and other wildfire fuels have dried out quickly in the midsummer swelter, triggering the annual extreme fire danger declaration and the restrictions that come with it.

"As of today, they're one notch below extreme," ODF spokeswoman Melissa Cano said. "A few days of triple-digit temperatures will only back up our decision."

It's a day of reckoning for ODF crews grappling with the consequences of a wet winter. While heavy snowpack remains in some high-elevation U.S. Forest Service lands, the wet winter brought a protracted low-elevation growing season that packed in more grass and brush, which are now tinder-dry, Cano said.

"That wet winter helped some of those brush patches become more dense," Cano said. "The threat of fast-moving grass fires is very much a concern."

Crater Lake National Park officials on Friday enacted Stage 1 fire restrictions that ban backcountry campfires and smoking other than in vehicles sporting ashtrays or while standing in a 3-foot diameter patch of land devoid of burnable material, according to the National Park Service.

The Rogue River-Siskiyou National Forest has opted to keep its fire-restriction level at "high," because upper-elevation forests are not as dry as low-elevation lands.

"We're still at high, and we haven't had any discussions about going to extreme at this time," forest spokeswoman Chamise Kramer said Friday.

While extreme fire danger on ODF-protected lands bans the private use of power saws and other spark-creating tools in wildlands, as well as banning the mowing of dry or dead grass, the designation does not change the Industrial Fire Precaution Level 2 restrictions for loggers and other woods-workers, according to state forestry.

High pressure throughout the West will trigger the prolonged heat pattern that will bring a longer heat run than the standard one or two days of triple-digit temperatures, Sandler said.

"People know it's going to be hot," Sandler said. "One hundred (degrees) seems to be the magical temperature for people. They see 100, they know it's going to be really hot."

— Reach Mail Tribune reporter Mark Freeman at 541-776-4470 or mfreeman@mailtfribune.com. Follow him on Twitter at www.twitter.com/MTwriterFreeman.