Light rain fell Thursday around a southeastern Arizona observatory threatened by two wildfires, helping firefighters protect multimillion-dollar telescopes but creating the potential for stronger winds.

The precipitation on rugged Mount Graham (search) helped raise the humidity level to 30 or 40 percent, much higher than it had been in recent days, said Brent Wachter, a National Weather Service meteorologist.

High temperatures and low humidity -- about 15 percent in recent days -- had been driving the wildfires threatening the $200 million Mount Graham International Observatory (search) and two communities of summer homes.

The higher humidity could slow the wildfire's growth, but it also created the potential for high winds that could spread the flames and lightning strikes that could spark more fires. The Mount Graham fires were both started by lightning.

"This is a bittersweet day," Wachter said.

He said forecasts call for wetter weather Friday and into the weekend in the Mount Graham area.

Firefighters focused their efforts Thursday on protecting the nearly 100 homes in Turkey Flat (search) and Columbine (search) on the flanks of the mountain. They also reinforced protection for the observatory.

On the road leading to Turkey Flat, a group of firefighters spent part of Thursday cutting down brush in preparation for a backburn, a fire set intentionally to clear out vegetation that feeds a wildfire.

"You don't want to see anybody lose valuables or possessions," said firefighter Stuart Rodeffer. "Homes are people's lives."

Officials said the fires, which have charred more than 26,000 acres, had grown no closer to either community by midday Thursday.

One fire, estimated at 16,879 acres, was burning up a canyon and officials were worried it would reach the roughly 74 cabins at Turkey Flat. The fire also was within a quarter-mile of the observatory.

Another fire, which had burned 9,941 acres, was about 11/2 to two miles from Columbine, a community of about 15 homes and cabins.

The two fires were approaching the observatory from different directions, but officials were hopeful they could save the facility. It was nearly surrounded by defensive lines cut by bulldozers and reinforced with burned-out areas and a sprinkler system. Crews hoped to enhance the line Thursday.

The two blazes were considered 25 percent contained, according to authorities. They estimated the firefighting effort had cost $5.8 million.

Elsewhere, officials planned to keep closed for a few more days the only direct highway linking Phoenix to Payson, a popular summer destination, because of erratic fire behavior on a 109,900-acre blaze in the Tonto National Forest in central Arizona.

The fire crossed State Route 87 on Wednesday night. The lightning-caused fire, which started June 24, was considered 25 percent contained by Thursday.

In Washington state, officials lifted a voluntary evacuation order after firefighters made significant progress on one of two fires burning near Lake Chelan.

The fire, about three miles east of the lake and the Columbia River, was estimated at about 4,205 acres, but firefighters had contained about 70 percent of the blaze, said Carson Berglund, fire information officer.

In Alaska, cooler, wetter weather slowed two fires northeast of Fairbanks, but fire officials said a soaking rain would be needed to seriously reduce fire danger.