The Labor Day 2020 east wind event

What happened

Early September brought a ridge of high pressure and heat, then an unusually strong cold front that pushed in from the north and east on Labor Day afternoon. West of the Cascades that meant hard east winds blowing down off the Cascades and Coast Range, with ridge-top gusts of 50 to 70 mph and 92 mph on Mount Hebo. The Portland airport gusted to 52 mph, and the wind held through much of the 8th.

The air was extremely dry and late-summer fuels were at their driest. In NOAA’s account, wind-thrown trees and downed power lines started at least 13 new fires in the Portland office’s area while fires already burning grew explosively. Large parts of Detroit, Gates and Mehama were destroyed, and parts of Idanha, Mill City and Lyons burned.

East of the Cascades the front brought northerly gusts of 40 to 65 mph, fanned more than 20 fires in eastern Washington and raised dust storms that closed I-90 and other highways. A fire started by a tree on a power line burned 80 percent of Malden and part of Pine City. Around Puget Sound, limbs on wires caused outages in Burien, Beacon Hill, Fife and Browns Point, and the Sumner Grade fire started when wind pushed trees into power lines.

The storm in NOAA’s numbers

NOAA’s Storm Events Database files this storm as 6 episodes from the National Weather Service offices in Spokane (OTX), Pendleton (PDT), Portland (PQR) and Seattle (SEW), dated September 7–8, 2020. Counting the six tree-relevant report types (high wind, strong wind, thunderstorm wind, ice storm, winter storm and heavy snow), the episodes hold 22 reports: 12 high wind and 10 strong wind (10 in Oregon; 12 in Washington). The same episodes hold 16 other reports (wildfire 9, dust storm 7), which are not counted in that total. The highest gust among the wind reports is 80 knots (about 92 mph), measured, in NOAA’s Coast Range of NW Oregon forecast zone in Oregon. Of the counted reports, 11 mention trees in the narrative.

A report is one entry per forecast zone or county per event, so one storm crossing many zones produces many reports. Gusts are in knots as NOAA records them (1 kt is about 1.15 mph).

Affected counties

34 counties have at least one counted report (19 in Oregon; 15 in Washington). The most reports touched Spokane County, WA (4), Clackamas County, OR (3) and Lane County, OR (3). Most wind, ice and snow reports are filed by forecast zone, and a zone report is assigned here to every county that zone covers, so a county’s number is the reports that touched it, not separate incidents.

Damage, deaths and injuries

NOAA’s property damage field for these episodes adds up to $4.69 billion in nominal dollars, as entered by the NWS offices at the time and not adjusted for inflation. The event records list 7 deaths (7 direct, 0 indirect) and 2 injuries across these episodes. NOAA’s fatality file gives a location for each death it holds: “Other” 5; “Unknown” 1; “Outside/Open Areas” 1.

The dollar figure is not wind damage in the usual sense. NOAA’s Portland office entered wildfire losses against its wind reports, including $2 billion for the north Oregon Cascade foothills, $1 billion for the north Oregon Cascades and $950 million for the south Washington Cascades, noting that many wind-damaged areas later burned. Wildfire, dust and wind reports from the Spokane office add about $15.1 million. Five deaths on the foothills report are coded “Other”, one was the Ochoco falling-tree death, and one was a person caught by an eastern Washington wildfire. None is coded “Under Tree”.

What it meant for trees

11 of the 22 wind reports mention trees: an apartment building and several cars hit in Spokane, a tree on a house in Hermiston, trees and lines down around Yakima County, a large Douglas fir that lost its top in the south Washington Cascade foothills, and widespread tree damage in the north Oregon Cascade foothills, much of which later burned. In the Ochoco National Forest a falling tree killed a person.

This was a different hazard from a winter gale. Trees were in full leaf, soils were dry, and the wind came from the east, the opposite of the usual storm direction west of the Cascades. Every tree that fell across a power line in dry grass or timber was a possible ignition.

What homeowners can learn from it

• Get trees off your service line before fire season. Start with your utility (PGE tree trimming) and read tree removal near power lines; defensible space work is in creating a defensible space.
• Have scorched and wind-damaged trees assessed before you rebuild under them. See dead tree removal for what a crew looks for.
• Photograph before anything is moved. Pictures of the tree, the stump or root plate and the damage are the evidence an insurer will want; storm damage and tree insurance in Oregon and storm damage and tree insurance in Washington explain what policies usually cover.
• If a tree is on the house, a car or a line, get people out of reach first. Then call the utility for anything touching wires; emergency tree service and fallen tree removal cover what happens next, and tree work safety explains why a crew should handle trees under tension.

Local pages: emergency tree service in Salem, Portland and Spokane. Before the next storm season, the tree risk checklist walks you around your own trees, and Oregon storm records and Washington storm records put this storm in context.

How this page was built

Every number above is computed from NOAA’s Storm Events bulk files for episodes 150848, 150837, 152510, 153195, 153297, 153298. Episodes were chosen by ranking all Washington and Oregon episodes from 2016 to mid-2026 on tree-relevant report counts, property damage and tree mentions, and episodes from different offices or states were merged when their narratives describe the same system on the same dates. Fire damage and deaths in the weeks that followed are outside this page, which covers only what NOAA filed under these six episodes. The counted reports exclude the wildfire and dust storm reports filed in the same episodes. Damage figures are NOAA’s nominal-dollar estimates and are often blank. See all storms on the storm history index and the site’s methodology.