Mt Hood · Aug 28-30 · 4 days out Updated Mon Aug 24, 5:00 AM · refreshes daily at 5am

Still on, but worth watching.

9 in 10chance the weekend is fine - clear or lightly hazy

The air at the house is clean right now, and every ensemble we have says the east wind that would drag the big fire's smoke over the mountain is unusually unlikely this weekend. Most likely you get clear to slightly hazy skies, with the worst single day landing in the 20s to 40s — that's good air by any phone app's standard.

The real risk isn't the big fire, it's the smaller uncontained ones 12 to 19 miles south and west that are on your side of the mountain: if one of them makes a run, a calm night can settle its smoke into the valley and hand you one genuinely unhealthy day, which we'd put at about one chance in five.

Known now5 of 5 forecast sources already cover your dates
No horizonFire size and containment are observations, not forecasts — they can move this on any day
Decide byAug 27
What would change this
  • Evacuation zone at the housenone
  • US-26 open, Portland to Welchesopen
  • Air at Multorpor13 · Clear
  • Nearest fire outside 10 miles12.5 mi · Mitchell
  • Wind pushing smoke our wayno - SSE at 3 mph

So what are the odds?

If we ran this weekend 100 times, here is how they would split. Hover a row to pick it out of the dots.

6 in 1058%Clear weekend AQI 0-50
Mt Hood sharp against blue sky, maybe milky haze on the southern horizon at sunset; nobody comments on the air.
nothing
3 in 1028%Hazy but fine AQI 50-100
Whitish sky, ridgelines soften, a faint campfire smell in the morning that burns off by noon. Sunsets go orange. Fine for hiking; a couple of people with asthma notice.
Nothing cancels. Do the long hike in the morning before the afternoon haze thickens, and close the windows overnight.
1 in 109%One smoky day AQI 100-150
You wake up to a valley full of gray, the far side of the river is indistinct, smoke smell indoors. Sun is a dim orange disc until midday. Everyone feels it in their throat after an hour outside.
That day moves indoors — no hiking, no long outdoor meals. Run a HEPA purifier, keep windows shut, N95s for anyone who goes out. The trip still happens.
0 in 105%Real smoke episode AQI 150+
Visibility down to a few hundred yards, headlights on at noon, indoor air noticeably smoky even with windows closed. Possible Level 1 evacuation notice or an air quality advisory on your phone.
Kids, older folks and anyone with asthma should not be there. Cut the trip short or relocate west toward the valley; check ODOT TripCheck before driving US-26.
Clear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendClear weekendHazy but fineHazy but fineHazy but fineHazy but fineHazy but fineHazy but fineHazy but fineHazy but fineHazy but fineHazy but fineHazy but fineHazy but fineHazy but fineHazy but fineHazy but fineHazy but fineHazy but fineHazy but fineHazy but fineHazy but fineHazy but fineHazy but fineHazy but fineHazy but fineHazy but fineHazy but fineHazy but fineHazy but fineOne smoky dayOne smoky dayOne smoky dayOne smoky dayOne smoky dayOne smoky dayOne smoky dayOne smoky dayOne smoky dayReal smoke episodeReal smoke episodeReal smoke episodeReal smoke episodeReal smoke episode
Clear AQI 0-50
You can see the mountain. Nobody notices anything.
Hazy AQI 50-100
Visible haze, ridgelines soften, faint campfire smell.
Smoky AQI 100-150
Distinctly smoky, orange sun, eyes sting a little.
Bad AQI over 150
Mountain invisible. You smell it indoors.

Where the fires are

Fires near the house, drawn at their real shape from the federal perimeter data, over USGS terrain. Dashed rings are distance from the house; the shaded wedge is the only direction an east wind could carry smoke here from. Point at a fire for its details.

SandyBrightwoodWelchesGovernment Campan east wind would carry smoke from here10 mi20 miThe houseGrasshopper93,744 acres · 17.4 miAustin5,620 acres · 18.6 miThe Narrows13.9 miMitchell12.5 miSweetwater19.3 mifire perimetersmall fire, size knownlocated, size not reported10 milesEverything within 60 milesGrasshopperBenchAustinTen MileBeachcombHigh LavaThe NarrowsMitchellSweetwaterWest 80579 Ten Mile
SandyBrightwoodWelchesGovernment Campan east wind would carry smoke from here20 mi40 miThe houseGrasshopper93,744 acres · 17.4 miBench67,071 acres · 45.5 miAustin5,620 acres · 18.6 miBeachcomb2,346 acres · 49.5 miThe Narrows13.9 miMitchell12.5 miSweetwater19.3 mifire perimetersmall fire, size knownlocated, size not reported10 miles

Solid dots are fires too small to draw at this scale but whose size is known. A dashed circle would mean a fire that has been located but has no published perimeter - size unknown, not small.

Beyond this frame, and too far to threaten the house but close enough to add regional haze: Bench (67,071 acres, 45.5 mi SSE), Ten Mile (4,834 acres, 56.7 mi SE), Beachcomb (2,346 acres, 49.5 mi SSE), High Lava (1,915 acres, 37.0 mi N).

An outline is only as current as the last mapping flight, which is not the same as when this page refreshed. Outlines flown — Grasshopper Aug 23 · Austin Aug 23 · The Narrows Aug 23 · Mitchell Aug 16. The oldest is Mitchell, 7 days behind. Acreage and containment are refreshed far more often than the outlines are re-flown — those figures were last updated Aug 23, 10:07 PM, so a fire may already be larger than the shape drawn for it.

Terrain: USGS 3DEP (public domain). Roads and water: © OpenStreetMap contributors (ODbL). Fire perimeters: NIFC.

Want to check it yourself, or see the rest of the state? The Oregonian's wildfire tracker is live and updates every 15 minutes.

Day by day

Fri Aug 28
Clear
likely 29 - could reach 76
6% chance of a smoky day
Sat Aug 29
Clear
likely 29 - could reach 80
7% chance of a smoky day
Sun Aug 30
Clear
likely 32 - could reach 90
9% chance of a smoky day

The specific odds

All three days clear60%
At least one smoky day (100+)13%
Two or more smoky days6%
At least one bad day (150+)5%
US-26 closed during the trip3%
Evacuation level at Welches6%

The one thing that would bring smoke here

3%of 156 ensemble member-days show the east wind that would bring smoke
vs 31% in a normal year — 28 points below normal
By trip day 08/28: 0% · 08/29: 0% · 08/30: 10%
By model gem global 21 members → 6% · gfs05 31 members → 1%
Base rate by year 2025: 22% · 2024: 44% · 2023: 44% · 2022: 22% · 2021: 22% (45 days, trip dates +/-3 days)

The long-range ensembles show less east-wind risk than a normal year — weak evidence, but pointing the right way.

Caveat: this counts days whose dominant wind is easterly, which at a valley site also picks up ordinary overnight down-valley drainage, not only the Gorge-outflow events that actually carry smoke. Forecast and base rate are measured the same way, so the gap is the meaningful part; the absolute percentages are not a chance-of-smoke.

When we'll actually know more

It is not one cut-off. Five sources arrive on five different dates, and the darker the strip, the more of them cover your weekend. Hover any day for the count.

Mon Aug 24Tue Aug 25Wed Aug 26Thu Aug 27Fri Aug 28Sat Aug 29Sun Aug 30Fire size & containmentAug 24 - todayAug 30 - trip ends
Hover a dayto see the forecast we logged that morning and how much was known.

▼ Since 2026-08-10 the forecast has moved better (-7 on the likely worst day) across 15 daily updates. Shading above shows source coverage, not this movement - hover a past day to see what we said that morning.

nowFire size & containment
how big the fires are and whether they are being held
nowLong-range ensembles (GEFS 0.5 + GEM)
wind direction, 52 members · reaches 32 days out
nowECMWF ensemble (51 members)
wind direction, the sharpest ensemble · reaches 13 days out
nowDeterministic weather (16-day)
day-by-day wind and temperature · reaches 15 days out
nowAir-quality / smoke model (CAMS)
actual AQI at the house · reaches 6 days out

Why we think this

The big fire, Grasshopper at 93,744 acres, is 17 miles east with Mt Hood between it and the house, and getting its smoke to Welches requires easterly flow that the ensembles put at 3% of member-days against a 31% climatological rate for this window — a 28-point negative departure across two model families is real evidence against the scenario the bad case depends on, not just an absence of evidence. What the terrain note gets wrong is that not all the fires are east: Mitchell (12.5 mi S), The Narrows (13.9 mi SSW, 0% contained), Austin (18.6 mi S, 5,620 acres, 0% contained) and Sweetwater (19.3 mi W, size unreported) are all on the west slope with no ridge between them and the house, so they need no wind reversal at all — just the light southerly drainage flow the NWS is already forecasting. Against that, the house is reading 13 right now with the wind blowing from the fires toward it, which tells you the current emissions are small and the mixing is efficient; the smoke in the forecast is diffuse and largely aloft. These fires will still be burning on the 28th — Oregon fires this size in a record-drought year with fuels fully cured do not go out in four days, and the first season-ending rain almost never arrives before mid-September — so the question is transport, not persistence, and transport is the part that looks favorable.

A normal late August here is Clear - median AQI 12 across the last 4 years. On these exact dates: 2025: 16 · 2024: 10 · 2023: 11 · 2022: 11.

We are forecasting a worst day of 35, 23 points above that base rate. That departure rests entirely on the reasoning above; judge it for yourself.

What the bad version needs:
The Austin fire (5,620 acres, 0% contained, 18.6 mi due S) or The Narrows (232 acres, 0% contained, SSW) makes an afternoon run in fully cured fuels — no east wind required, these are on the house's own side of the crest. → Wind stays light and southerly (NWS already has SSE at 2-5 mph and 'areas of smoke'), so the plume drifts north down the Salmon/Sandy drainages instead of being ventilated. → An overnight inversion traps that smoke in the valley floor at Welches and it doesn't mix out until late morning, so the 24-hour average — not just a bad hour — lands at 100-150.
First visible signal: The Multorpor / Government Camp reading on AirNow or PurpleAir climbing past 50-60 in the evening and staying there past midnight — an evening spike that does NOT clear by morning is the tell. Second signal: NWS Portland upgrading the Welches wording from 'patchy smoke' to 'smoke', or Oregon DEQ issuing an Air Quality Advisory for the Mt Hood corridor. - about 2 days ahead
Key drivers, and what would change our minds
  • East-wind ensemble at 3% vs 31% climatology (-28 pts) — the Grasshopper transport path is largely shut off
  • Mt Hood shields the east fires, but Mitchell, The Narrows, Austin and Sweetwater are all on the house's own side of the crest and need no wind reversal
  • Austin (5,620 ac) and The Narrows (232 ac) both at 0% containment 13-19 miles away, in fully cured fuels
  • Sweetwater, 19 mi W with no reported acreage — an unquantified fire sitting directly upwind of the dominant onshore regime
  • Currently 13 AQI at Multorpor despite wind blowing from fires toward the house — emissions are small and mixing is good
  • Season anomaly of 2.0x measured in local AQI, applied once to a climatological median of 12
  • The Government Camp monitor reading above 60 at sunrise, not just in the evening — that means smoke is settling into the valley overnight instead of blowing through
  • Austin fire acreage roughly doubling on InciWeb, or still showing 0% containment on the 27th
  • Sweetwater finally getting a reported size, and it being large — anything over a few hundred acres 19 miles due west matters more than everything to the east
  • Any Level 1 'Be Ready' evacuation zone appearing near Welches, Zigzag or Brightwood on the Genasys Protect app
  • The Welches point forecast switching to sustained east or northeast wind for Aug 29-30 — that would mean the ensembles busted and Grasshopper is back in play
  • A new fire start reported anywhere in the Sandy, Zigzag or Clackamas drainages between now and Thursday

Fires within 60 miles

12.5 miMitchell S16 acres
13.9 miThe Narrows SSW232 acres · 0% contained
17.4 miGrasshopper E93,744 acres · 76% contained
18.6 miAustin S5,620 acres · 0% contained
19.3 miSweetwater Wsize not yet reported
37.0 miHigh Lava N1,915 acres · 25% contained
41.7 miWest 8 ENEsize not yet reported

The biggest hole in this forecast: 2 of the nearby fires (Sweetwater, West 8) have no size reported yet. Whether those are 300-acre creepers or 20,000-acre runners is most of the answer.

Pack this regardless

  • N95 or KN95 masks — a real one each, not cloth or surgical
  • One portable HEPA air purifier, or a box fan plus a MERV-13 furnace filter and duct tape (a $30 version works)
  • Rescue inhalers and any allergy/asthma medication, including for people who only 'sometimes' need it
  • A rainy-day plan: cards, board games, a movie list — the contingency is an indoor day, not a cancelled trip
  • Eye drops and a way to keep the house sealed (know which windows actually close and whether there's AC or a fan)

If the weekend is clean you carried masks for nothing. If it is not, this is the difference between a bad weekend and a ruined one.

Watch list, and getting there

  • Government Camp / Multorpor PM2.5, especially the 8pm-6am hours - Evening reading above 60 that is still above 60 at sunrise — that's valley pooling, not a passing whiff (fire.airnow.gov or the PurpleAir map)
  • Austin fire acreage and containment - Acreage jumps more than ~50% in a day, or it is still at 0% containment on Aug 27 (inciweb.wildfire.gov)
  • Sweetwater fire — size is currently unreported and it sits 19 mi due W, upwind in the normal onshore regime - Any published size over ~500 acres, or any mention of growth toward the Bull Run / Sandy corridor (inciweb.wildfire.gov / Oregon Dept of Forestry incident page)
  • Welches point forecast wind direction and smoke wording - Sustained east or northeast wind appearing for Aug 29-30, or 'smoke' replacing 'patchy smoke' (forecast.weather.gov, search 'Welches OR')
  • Evacuation levels for Clackamas County - Any Level 1 zone touching the Welches / Zigzag / Brightwood area (clackamas.us/dm or the Genasys Protect app)
  • US-26 status - Any closure or pilot-car control between Sandy and Government Camp (tripcheck.com)
Sandy5.7 mi
Brightwood10.9 mi
Welches14.3 mi

Distance from each point on the drive in to the nearest fire. TripCheck is the authority on closures.

If we wanted cleaner air, where would we go?

Ranked by how bad these dates have historically been at each place. The coast is not just cleaner today — it sits upwind of everything burning, so it only smokes during an east-wind reversal, which is the same event that would smoke out the house.

“Bad day / typical” is what the air actually did on Aug 26 – Sep 1 in 2022, 2023, 2024 and 2025 — 28 days per place. The first number is the bad day: one day in ten was worse than this. The second is the typical day, the middle of the range. We rank on the bad day rather than the typical one, because the bad day is what would spoil a weekend.

Both are converted onto the same scale as the “now” column, so every AQI figure in this table is comparable. That conversion matters more than it sounds: the model these come from runs about 2.5× high on the coast but close to true inland, so before correcting it the coast looked far worse than it is.
PlaceBad day / typicalNow Official forecastNext 5 daysNearest fire
Newport coast18 / 159 ClearGood– steady102 mi · The Narrows
Cannon Beach coast22 / 1913 Clear▲ worsening88 mi · High Lava
Hood River east of crest22 / 1528 ClearModerate– steady21 mi · Grasshopper
Manzanita coast24 / 2213 Clear– steady87 mi · High Lava
Pacific City coast24 / 2113 Clear– steady91 mi · The Narrows
Astoria coast24 / 2116 ClearModerate▲ worsening84 mi · High Lava
Long Beach, WA coast27 / 2416 Clear▲ worsening97 mi · High Lava
Welches / Mt Hood booked29 / 2153 HazyGood▲ worsening14 mi · The Narrows
Silver Falls valley50 / 3716 Clear– steady33 mi · The Narrows
Portland valley54 / 4434 ClearGood– steady36 mi · High Lava
McMinnville valley56 / 4021 ClearGood– steady54 mi · The Narrows
Bend east of crest123 / 7293 Hazy▲ worsening22 mi · Akawa Butte
What each column covers, and where it comes from
FieldPeriod it coversWhat it is
Air right now08/24/26 4:00 PDTNearest EPA/AirNow ground monitor to each place, within 45 miles
airnow.gov
Official forecastissued 08/24/26 by Washington Department of EcologyNext published outlook for that reporting area — a human forecaster's call
Oregon DEQ via AirNow
Next 5 daystoday's model run, covering 2026-08-28Direction only. Copernicus CAMS global air-quality model
open-meteo.com
Bad day / typicalAug 26 – Sep 1 in 2022, 2023, 2024, 2025 (28 days each)CAMS reanalysis for those exact dates, then converted to the monitor scale
open-meteo.com
Scale conversionmedian of 14 daily model-vs-monitor pairs, 2026-08-08 to 2026-08-21Median of daily model-vs-monitor ratios — the bias differs by place, from 0.342 on the coast to 1.091 inland
AirNow daily archive
Nearest firequeried Aug 24 5:00 AMPerimeter polygons of fires over 100 acres, distance to the burned edge
NIFC WFIGS

Every AQI figure above is on the ground-monitor scale — the same thing your phone shows. n/a means the model and the monitors disagree so sharply at that spot that we cannot honestly place it on that scale (steep terrain inside a coarse model grid cell — the Gorge is the usual culprit); those rows are sorted by today’s reading instead.

How this is made, and what it cannot do

Fire perimeters from NIFC, evacuation zones from Oregon OEM, weather and alerts from NWS, air quality from AirNow (Multorpor, 8.7 mi away). The forecast is judged by Claude Opus 5 on the live data above, sampled 5 times and pooled conservatively.

It is a judgement, never scored against an outcome. Nobody forecasts smoke this far out: NOAA's smoke model runs 48 hours and the EPA's air-quality forecast is for tomorrow. Two-to-six weeks ahead is what meteorologists call the predictability desert. Anyone giving you a number for the trip right now - us included - is giving you a base rate with a story attached.

How thin the history is. The air-quality record for this spot begins in 2022, so "normal" here is built from just 4 years (2022, 2023, 2024, 2025). In those 28 sampled days the worst single day was AQI 22, and none reached 100.

That record has never seen a bad Oregon smoke year — not 2020, when Portland sat above AQI 500 for days, nor 2017, 2018 or 2021. So the base rate below is drawn entirely from calm years, and the upper end of our range is an estimate rather than something history has shown us. It is the main reason not to read the good news too confidently.

Are these forecasts any good? Across 45 scored forecast-days, the air-quality model beat both simple baselines at 4 of 5 lead times. Where it does not, this page should not be trusted to out-guess them either.

AQI here means the highest 24-hour PM2.5 value touching a day, at the house, on the local monitor scale - the same thing your phone shows. The model's own restatement of the target: “I'm forecasting the US EPA AQI for PM2.5 — the version built on a 24-hour average concentration, which is what a phone weather or air quality app shows you — at the house in Welches, on the local monitor scale already calibrated from the model (I did not re-apply the 0.2 factor). For each calendar day I give the highest such 24-hour AQI value touching that day, and the headline number is the single worst of the three trip days, Aug 28-30, not the average across them.”

Updated daily at 5am. A convenience, not an authority -
if officials issue an evacuation order, follow it.