Times Observer photo by Josh Cotton The National Weather Service on Wednesday — citing sustained winds and low humidity — issued a special weather statement discouraging outdoor burning. Here, at the Allegheny National Forest headquarters, the fire risk was deemed “moderate.”

As if the smoke from the Canadian wildfires wasn’t enough, a sustained period of hot, dry days has officials discouraging outdoor burning.

“Normally by this time of year we are through our wildfire season but due to the dry conditions we are asking the public to particularly use extra care with any outside burning until we get some measurable precipitation,” DCNR District Forester Cecile Stelter said.

The National Weather Service — State College issued a special weather statement Wednesday morning for much of the state, citing an “elevated risk of wildfire spread” throughout the day.

Sustained winds combined with low humidity were cited as the reason for the statement.

Minimum relative humidity values will range from 20 to 30 percent.

“Abnormally dry to moderate drought conditions are also a contributing factor for the elevated risk of wildfire spread,” the statement explains. “Residents are urged to exercise caution if handling any potential ignition sources, such as machinery, cigarettes, or matches. If dry grasses and tree litter begin to burn, the fire will have the potential to spread rapidly.

This stretch of hot, dry weather — combined with several days of frost late last month — has also contributed to significant levels of defoliation for some species of trees.

“Depending on the stage of leaf development, some trees were impacted much more significantly than others,” Stelter explained. “We’ve noticed that White Oaks, Aspens and Locusts in particular seem to have been most affected in comparison to some of the other species overall.”

She explained that some leaves were “‘burnt’ or frozen” by the cold temperatures. Some closer to full foliage were able to withstand the cold.

“There are instances of the leaves at the top of some trees being impacted and the leaves at the bottom showing no affect,” she added. “Often it takes several weeks for the damage of cold temperatures to manifest itself. If the individual tree is otherwise healthy, then it should be able to send out a second round of leaves — however, if a tree is already stressed, then making it leaf out twice could have detrimental effects — including mortality.”

She said that an “additional factor to this cold/freeze event is the unusual hot/dry spell we are experiencing. That will also add stress to the trees and may cause some premature leaf drop.”