Dangerous fire weather conditions have settled across Oregon and Nevada heading into the final days of May, with the National Weather Service warning of elevated to critical fire danger due to the combination of gusty winds and low relative humidity expected to persist through Tuesday, May 26.

What the Forecast Shows

Meteorologists at the National Weather Service's Western Region offices confirmed that critical fire weather conditions are in effect across much of Oregon east of the Cascades, where afternoon minimum relative humidities are expected to fall into the single digits to low teens percent. Winds gusting 20 to 35 mph — with locally higher gusts in terrain-channeled corridors such as the Columbia Gorge — are making any ignition potentially explosive.

The NWS fire weather outlook for the broader West indicates that while low pressure will bring some rainfall to the Northern Plains and scattered mixed wet-dry thunderstorms are possible over portions of California, the Northern Rockies, and parts of Utah and Colorado, most of Oregon east of the Cascades will remain largely dry. The driest and most dangerous conditions are concentrated across the Desert Southwest, Great Basin, and east of the Cascades, where relative humidities will range from the single digits to 30 percent, lowest across the most exposed terrain.

Thunderstorm Lightning Threat

A secondary concern this week is the potential for dry or marginally wet lightning strikes accompanying isolated thunderstorm cells moving through portions of the Northern Rockies and interior Pacific Northwest. Lightning in conditions with critically low relative humidity and dry fuels can start new fire starts that go undetected for days before flaring in hot, windy conditions. Fire lookouts and aerial detection patrols are operating at heightened frequency across fire-prone zones in response.

Fuel Conditions Already Elevated

The fire weather risk this week is amplified by fuel conditions that are weeks ahead of their typical seasonal state. A warmer-than-average winter and below-average snowpack across much of Oregon and the broader Pacific Northwest accelerated the drying of grass and brush fuels. Fine fuels — grasses and small shrubs — are the primary driver of early-season fire spread, and they are currently at or near critically dry levels across much of Eastern Oregon, the Columbia Gorge, and the Oregon-Idaho border region.

The National Interagency Fire Center's current preparedness level is at Level 2, reflecting increasing regional fire activity and growing resource demands. Nationally, more than 5,000 personnel are currently assigned to fire incidents across the country, with activity increasing in several geographic areas over the past week.

Resident and Recreator Safety Tips

  • Avoid any outdoor burning, including burning debris piles, during elevated fire weather conditions.
  • Do not use equipment that generates sparks in or near dry grass and brush.
  • Be aware that red flag warning conditions mean any fire can escape containment within minutes of ignition.
  • Check the NWS fire weather outlook at weather.gov/fire before recreational activities in the backcountry.
  • Know your evacuation route — fire spread under these conditions can outpace evacuation efforts if residents wait too long.

Fire weather conditions are expected to moderate slightly by mid-week as a Pacific system brings some moisture to coastal and Cascade ranges, but fire officials caution that relief will be limited east of the mountains where fuels remain critically dry.