Mt Hood · Aug 28-30 · 8 days out Updated Thu Aug 20, 5:00 AM · refreshes daily at 5am

Everything is fine.

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

The large fire near the house is on the far side of Mt Hood, and the winds expected during your trip run the wrong direction to carry its smoke across the mountain to you. Expect a hazy weekend that smells faintly of campfire rather than a dangerous one — most likely somewhere in the upper 50s on your phone's air app on the worst day, which is about what it reads there right now.

The real risk isn't the fires already on the map; it's a new one starting closer to the house in the next week, which is why the group should take one more look on Tuesday the 25th before anyone drives out.

Known now4 of 5 forecast sources already cover your dates
Next updateAug 22 — Air-quality / smoke model
No horizonFire size and containment are observations, not forecasts — they can move this on any day
Decide byAug 25
What would change this
  • Evacuation zone at the housenone
  • US-26 open, Portland to Welchesopen
  • Air at Multorpor54 · Hazy
  • Nearest fire outside 10 miles12.5 mi · Mitchell
  • Wind pushing smoke our wayno - at 0 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.

3 in 1033%Clear weekend AQI 0-50
Mt Hood sharp against the sky from the deck, no smell, kids outside all day, phone app says Good or low Moderate every morning.
nothing
4 in 1043%Hazy but fine AQI 50-100
Milky white sky, the mountain a soft grey outline, an orange sunset, a faint campfire smell in the morning that burns off by early afternoon. Nobody healthy notices anything but the view; one or two people with asthma feel a scratchy throat.
Run a purifier in the main room, close windows overnight, move the long hike to the morning and keep the afternoon low-key.
2 in 1016%One smoky day AQI 100-150
You can't see the mountain at all and can barely see the ridge across the valley. Smell is obvious indoors. Eyes sting after an hour outside. Anyone with asthma or a heart condition is uncomfortable.
Everyone with a lung or heart condition stays inside with purifiers running; N95s for anyone who must be outdoors; cancel the hike, keep the trip.
1 in 108%Real smoke episode AQI 150+
Brown-orange daylight, visibility under a mile, headlights on at noon, the house smells smoky even shut up. Healthy adults get headaches and sore throats. Possible evacuation-readiness notices in the Hoodland corridor.
Sensitive people go home early; everyone else stays indoors with purifiers or the whole group relocates west toward Portland or the coast.
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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 houseGrasshopper92,456 acres · 17.4 miAustin3,760 acres · 19.0 miThe Narrows14.0 miMitchell12.5 mifire perimetersmall fire, size knownlocated, size not reported10 milesEverything within 60 milesGrasshopperBenchTen MileAustinBeachcombHigh LavaThe NarrowsMitchell0579 Ten MileOlson Road
SandyBrightwoodWelchesGovernment Campan east wind would carry smoke from here20 mi40 miThe houseGrasshopper92,456 acres · 17.4 miBench67,071 acres · 45.5 miAustin3,760 acres · 19.0 miBeachcomb2,346 acres · 49.5 miThe Narrows14.0 miMitchell12.5 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 (1,562 acres, 37.2 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 18 · Austin Aug 18 · The Narrows Aug 18 · Mitchell Aug 16. The oldest is Mitchell, 3 days behind. Acreage and containment are refreshed far more often than the outlines are re-flown — those figures were last updated Aug 20, 4:01 AM, 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 44 - could reach 105
11% chance of a smoky day
Sat Aug 29
Clear
likely 46 - could reach 114
13% chance of a smoky day
Sun Aug 30
Clear
likely 48 - could reach 122
15% chance of a smoky day

The specific odds

All three days clear35%
At least one smoky day (100+)22%
Two or more smoky days11%
At least one bad day (150+)7%
US-26 closed during the trip2%
Evacuation level at Welches6%

The one thing that would bring smoke here

5%of 156 ensemble member-days show the east wind that would bring smoke
vs 31% in a normal year — 26 points below normal
By trip day 08/28: 2% · 08/29: 6% · 08/30: 8%
By model gem global 21 members → 8% · gfs05 31 members → 3%
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.

Thu Aug 20Fri Aug 21Sat Aug 22Sun Aug 23Mon Aug 24Tue Aug 25Wed Aug 26Thu Aug 27Fri Aug 28Sat Aug 29Sun Aug 30Fire size & containmentAir-quality / smoke modelAug 20 - 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 worse (+16 on the likely worst day) across 11 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
Aug 22Air-quality / smoke model (CAMS)
actual AQI at the house · reaches 6 days out

Why we think this

The dominant smoke source, Grasshopper at 92,456 acres, is 17 miles due east with Mt Hood between it and the house, so it only reaches Welches under easterly downslope flow — and the ensembles put that at 5% of 156 member-days against a 31% climatological rate for the same calendar window, a 26-point deficit that both GFS and GEM agree on, which is the strongest single piece of evidence in the pack and it argues against the bad case. It is also 66% contained and will likely be 80%+ by the 28th. I did check the bearings rather than assuming the crest protects the house: Mitchell (12.5 mi S), The Narrows (14 mi SSW) and Austin (19 mi S) are all on the west side, the same side as the house, and Austin and The Narrows are 0% contained — that is why my number sits well above climatology despite the favorable wind signal. The realistic worst case here is not a dramatic east-wind event but the boring one: a near-calm, stagnant pattern (winds are already 0-2 mph) in which a local west-slope fire's plume pools in the Sandy River valley overnight and doesn't flush, which is almost certainly what is producing the 54 reading at Multorpor right now under otherwise clean flow. Against that, the season anomaly of 1.88x is measured at this exact location and already prices in this year's severity as it has actually manifested here, and 0 of 28 sampled days in this window ever exceeded 100 — though with the archive starting in 2022 I treat that zero as under-sampled, not as proof, which is where the 7% tail comes from.

A normal late August here is Clear - median AQI 17 across the last 4 years. On these exact dates: 2025: 23 · 2024: 14 · 2023: 15 · 2022: 16.

We are forecasting a worst day of 58, 41 points above that base rate. That departure rests entirely on the reasoning above; judge it for yourself.

What the bad version needs:
Austin (3,760 acres, 0% contained, 19 miles south and on the SAME west side of the crest as the house) or The Narrows makes a run in fully cured fuels, or a new fire starts on the west slope — with the country at Preparedness Level 5 since July 18, initial attack is thin and it gets 2-3 days to grow before it's boxed in. → The same quiet, near-calm pattern the ensembles are showing (2-8% easterly, winds already 0-2 mph) turns into stagnation: light up-valley flow carries the plume north into the Sandy River drainage by day, and nocturnal drainage pools it in the valley bottom overnight instead of flushing it. → Welches sits inside a valley-scale smoke pool that doesn't scour out for 24+ hours, dragging the 24-hour average past 150 — note this path never requires the east wind that the ensembles argue against.
First visible signal: A big overnight acreage jump for Austin or The Narrows on InciWeb, and — the thing a non-expert can actually see — the Government Camp/Multorpor reading on the AirNow app climbing past 80 in the evening and still being above 80 at 10am the next morning instead of clearing. - about 2 days ahead
Key drivers, and what would change our minds
  • Grasshopper (92,456 acres, 66% contained) is 17 miles EAST behind the Cascade crest — it needs easterly flow to reach the house, and containment is still climbing
  • Ensembles show easterly flow on only 5% of 156 member-days vs 31% climatologically for this window (-26 points), agreed on by two independent models
  • Two uncontained fires on the house's OWN side of the crest: Austin (3,760 acres, 0%, 19 mi S) and The Narrows (174 acres, 0%, 14 mi SSW) — these do not need an east wind
  • Multorpor is already reading 54 under calm, non-transport conditions, so there is a live local smoke source, not just distant haze
  • Season anomaly of 1.88x measured in local AQI at this location — real, but already counted once and not multiplied again
  • Record 2026 season: 2.34M acres, 96% drought, lowest-on-record April snowpack, PL5 since July 18 — this raises the odds of a NEW close ignition and slow initial attack over the 8-day lead, which is where most of my tail risk sits
  • The NWS forecast for Welches or Government Camp starts mentioning east or northeast wind, or 'offshore flow,' for Aug 28-30 — that single change would roughly double my odds of a day over 100
  • Austin fire grows past about 10,000 acres, or a Type 1 incident management team gets assigned to it
  • Any new fire is reported within 25 miles of Welches between now and the 27th
  • The AirNow reading at Government Camp stays above 80 through the night and is still above 80 at 10am — that means smoke is pooling in the valley rather than flushing
  • Clackamas County issues a Level 1 'Be Ready' evacuation notice for Zigzag, Welches, Rhododendron or Brightwood
  • The other direction: a Pacific front with measurable rain shows up in the 7-day for that weekend — that would be season-ending for smoke and I'd move straight to GO with no contingency

Fires within 60 miles

12.5 miMitchell S16 acres
14.0 miThe Narrows SSW174 acres · 0% contained
17.4 miGrasshopper E92,456 acres · 66% contained
19.0 miAustin S3,760 acres · 0% contained
37.2 miHigh Lava N1,562 acres · 8% contained
45.5 miBench SSE67,071 acres · 90% contained
49.5 miBeachcomb SSE2,346 acres · 100% contained

Pack this regardless

  • Two or three true HEPA air purifiers sized for the main room, plus one for the bedroom of anyone with asthma — this is the single highest-value item and rentals rarely have them
  • A box of N95 or KN95 respirators, two per person; cloth masks, surgical masks and bandanas do nothing for smoke
  • Rescue inhalers and allergy/asthma medication for everyone who uses them, plus one spare — pharmacies out there are a drive
  • A plan and the tape/cardboard to keep windows shut and any AC or heat pump set to recirculate rather than fresh-air intake
  • An indoor-afternoon backup: cards, board games, a laptop and HDMI cable — assume at least one afternoon gets driven inside
  • A full tank of gas leaving Portland and offline maps downloaded; US-26 is the only real road in and out of Welches

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

  • Live PM2.5 at Government Camp / Multorpor, 8.7 miles away — the monitor this whole forecast is calibrated to - Above 80 two mornings in a row, or a reading that stays high overnight instead of dropping by mid-morning — that's a local pool forming, act on it. (AirNow app or fire.airnow.gov (Fire and Smoke Map))
  • Acreage and containment on Austin and The Narrows (the two 0%-contained fires south of you), and whether any NEW fire appears within 25 miles - Austin past 10,000 acres, a Type 1/2 team ordered for it, or any new named fire inside 25 miles of Welches. (inciweb.wildfire.gov and nwccweb.us (Northwest Coordination Center morning report))
  • Wind direction language in the point forecast for Welches/Zigzag on Aug 28-30 - Any mention of east or northeast wind, or 'offshore flow' — that is the one pattern that could bring the 92,000-acre Grasshopper fire over the crest to you. (weather.gov/pqr, or any phone weather app's hourly wind for the trip days)
  • Evacuation notices for the Hoodland corridor - Any Level 1 'Be Ready' for Zigzag, Welches, Rhododendron, or Brightwood. (Clackamas County alerts (clackamas.us/dm) and the Hoodland Fire District #74 Facebook page)
  • Oregon DEQ smoke outlook for the Mt Hood corridor - A published outlook naming Unhealthy for Sensitive Groups or worse for the Hoodland/Government Camp area on any trip day. (oregonsmoke.blogspot.com)
Sandy19.4 mi
Brightwood15.6 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 coast20 / 1719 ClearGood▲ worsening102 mi · The Narrows
Manzanita coast22 / 2131 ClearGood– steady87 mi · High Lava
Cannon Beach coast23 / 2031 ClearGood▲ worsening88 mi · High Lava
Pacific City coast23 / 2031 ClearGood▲ worsening91 mi · The Narrows
Astoria coast26 / 2321 ClearGood▲ worsening84 mi · High Lava
Long Beach, WA coast27 / 2421 ClearGood▲ worsening97 mi · High Lava
Welches / Mt Hood booked37 / 289 ClearModerate– steady14 mi · The Narrows
Silver Falls valley45 / 3352 HazyGood– steady33 mi · The Narrows
Portland valley48 / 3855 HazyGood– steady36 mi · High Lava
McMinnville valley53 / 3746 ClearGood– steady54 mi · The Narrows
Bend east of crest119 / 70110 SmokyModerate▼ clearing22 mi · Akawa Butte
Hood River east of crestn/a91 HazyModerate– steady21 mi · Grasshopper
What each column covers, and where it comes from
FieldPeriod it coversWhat it is
Air right now08/20/26 4:00 PDTNearest EPA/AirNow ground monitor to each place, within 45 miles
airnow.gov
Official forecastissued 08/20/26 by Oregon Dept. of Environmental QualityNext published outlook for that reporting area — a human forecaster's call
Oregon DEQ via AirNow
Next 5 daystoday's model run, covering 2026-08-24Direction 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, 2026-07-31 to 2026-08-13Median of daily model-vs-monitor ratios — the bias differs by place, from 0.375 on the coast to 1.056 inland
AirNow daily archive
Nearest firequeried Aug 20 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 32, 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 25 scored forecast-days, the air-quality model beat both simple baselines at 2 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 am forecasting the US EPA AQI for PM2.5 as a 24-hour average — the highest such 24-hour AQI value touching each calendar day at the Welches house — on the local monitor scale that a phone app like AirNow shows, matching the nearby Multorpor station reading 54 today, with no further bias correction applied on my part since the pack's numbers are already calibrated off the model scale. 'Worst day of trip' is the single highest of those three daily values across Aug 28, 29 and 30, not their average.”

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