Mt Hood · Aug 28-30 · -45 days out Updated Mon Oct 12, 5:00 AM · refreshes daily at 5am

Everything is fine.

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

First, a data problem you should know about: the evidence pack is dated October 12 but the trip dates are August 28-30, so this is a reconstruction of a weekend that has already happened, not a forecast — if you meant a future weekend, re-run it with the right dates. For the weekend as given, the house sits on the wet west side of the Cascades where the usual late-summer sea breeze pushes clean ocean air up the Sandy River valley, and the big fire nearby (Grasshopper, ~94,000 acres) was on the far side of Mt Hood, so it only reaches you when the wind flips and blows from the east.

Most likely you got a faintly hazy sky with air in the 20s to 40s, a meaningful chance of one genuinely smoky day near 100, and roughly a one-in-ten chance of a real smoke episode above 150 that would have sent people indoors.

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 25
What would change this
  • Evacuation zone at the housenone
  • US-26 open, Portland to Welchesopen
  • Air at Multorpor10 · Clear
  • Nearest fire outside 10 miles13.9 mi · The Narrows
  • 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.

4 in 1038%Clear weekend AQI 0-50
Mt Hood sharp-edged all three days, blue sky, maybe a thin brown smudge on the eastern horizon at sunset; nobody mentions the air.
nothing
3 in 1033%Hazy but fine AQI 50-100
Milky white sky, the ridge across the valley softened, a faint campfire smell in the morning that burns off by noon; sensitive people notice, the hike still happens.
Move the long hike to the morning, run the purifier at night, keep the windows shut after dark when cold air drains down the valley and pools smoke.
2 in 1018%One smoky day AQI 100-150
One day you can look straight at an orange sun, visibility a mile or two, throats scratchy, the kids coughing after an hour outside; the other two days are much better.
That day becomes an indoor day — board games, drive west to the valley floor or the coast for the afternoon, N95s for anyone going outside.
1 in 1012%Real smoke episode AQI 150+
Ash flecks on the car, the far side of the river gone, headaches by mid-afternoon, indoor air visibly hazy even with the house closed up.
Cut the trip short or relocate west; anyone with asthma, a heart condition, or a small child should not stay.
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 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 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 dayOne 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 episodeReal smoke episodeReal 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 houseGrasshopper93,971 acres · 17.4 miAustin12,888 acres · 18.3 miThe Narrows13.9 mifire perimetersmall fire, size knownlocated, size not reported10 milesEverything within 60 milesGrasshopperAustinHigh LavaThe Narrows
SandyBrightwoodWelchesGovernment Campan east wind would carry smoke from here20 mi40 miThe houseGrasshopper93,971 acres · 17.4 miAustin12,888 acres · 18.3 miThe Narrows13.9 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: High Lava (2,899 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 Sep 15 · Austin Sep 16 · The Narrows Sep 15. The oldest is The Narrows, 27 days behind. Acreage and containment are refreshed far more often than the outlines are re-flown — those figures were last updated Sep 29, 4:26 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 42 - could reach 122
15% chance of a smoky day
Sat Aug 29
Clear
likely 46 - could reach 134
17% chance of a smoky day
Sun Aug 30
Clear
likely 48 - could reach 142
18% chance of a smoky day

The specific odds

All three days clear34%
At least one smoky day (100+)30%
Two or more smoky days15%
At least one bad day (150+)12%
US-26 closed during the trip4%
Evacuation level at Welches7%

The one thing that would bring smoke here

Long-range wind signal unavailable this run.

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.

Hover a dayto see the forecast we logged that morning and how much was known.

▲ Since 2026-08-10 the forecast has moved worse (+26 on the likely worst day) across 63 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 11 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 controlling mechanism at this address is flow direction, not fire proximity: Welches sits in the Sandy River valley on the wet west slope, and in late August the default is onshore westerly flow through the Columbia Gorge that keeps the corridor in the Good band even in severe statewide fire years — 2024 set the prior acreage record and this location still averaged a daily max of 12 in this window. The two fires that matter are Grasshopper, 94,000 acres at 17 miles due east, and Austin, 12,900 acres at 18 miles south; the pack's own terrain note that Mt Hood 'sits between' the house and the eastern fires overstates the protection, because easterly gradient events move smoke through the Gorge and down the east-southeast-draining Sandy valley regardless of the peak, and the Austin fire to the south needs no crest crossing at all. Against that, climatological offshore frequency in this window is 31% with no ensemble available to say whether the actual weekend beat or missed it, and the local measured season anomaly is 1.05 — essentially normal air at this location despite a record statewide season, which is the single strongest piece of evidence that the transport pathway stayed closed.

A normal late August here is Clear - median AQI 15 across the last 4 years. On these exact dates: 2025: 19 · 2024: 12 · 2023: 13 · 2022: 13.

We are forecasting a worst day of 68, 53 points above that base rate. That departure rests entirely on the reasoning above; judge it for yourself.

What the bad version needs:
An upper ridge builds over the Pacific Northwest in the last days of August, the thermal trough shifts west of the Cascades, and the surface pressure gradient reverses to offshore (east) — climatologically a 31% occurrence in this calendar window, and 44% in two of the last five years. → That easterly flow draws smoke from the 94,000-acre Grasshopper fire 17 miles due east down the Columbia Gorge and over/around the crest; Mt Hood blocks the direct line of sight but not the flow, and the Sandy River valley drains from the east-southeast straight to the house. A south component instead pulls in the 12,900-acre Austin fire 18 miles south, which needs no crest crossing at all. → Smoke settles into the valley overnight under a radiative inversion and does not mix out, so the 24-hour average — not just the afternoon peak — climbs through 100 and, if the east gradient holds a second day, through 150.
First visible signal: The NWS Portland forecast switching the Welches/Government Camp wind from west or northwest to east or southeast, and an Air Quality Advisory from Oregon DEQ for the Cascade foothills — both visible on a phone weather app before any smoke is smellable. - about 2 days ahead
Key drivers, and what would change our minds
  • The trip dates are in the past relative to the pack's own clock — every live field describes October, not the trip weekend
  • Onshore westerly marine flow is the late-August default in the Sandy valley and keeps this address clean most days
  • Grasshopper, 94,000 acres at 17 miles east — large, close, and reachable via Gorge easterlies despite Mt Hood
  • Austin, 12,900 acres at 18 miles south — on the same side of the crest, so no terrain barrier at all
  • Climatological offshore frequency of 31% with no ensemble available to refine it for the actual weekend
  • Measured local season anomaly of 1.05 — normal air here despite a record 2.34-million-acre statewide year
  • The AirNow historical record for Aug 28-30, 2026 at Government Camp/Multorpor — a direct answer that overrides this entire estimate
  • Corrected trip dates: if the real trip is in 2027 or later this fall, the fire and weather picture is completely different
  • An NWS Portland forecast showing east or southeast wind at Welches for two straight days
  • An Oregon DEQ air quality advisory covering the Clackamas County foothills or the Mt Hood corridor
  • A new fire appearing on Watch Duty west of the Cascade crest within 25 miles of the house
  • Acreage on Grasshopper or Austin jumping sharply while containment percentage falls

Fires within 60 miles

13.9 miThe Narrows SSW304 acres · 98% contained
17.4 miGrasshopper E93,971 acres · 98% contained
18.3 miAustin S12,888 acres · 98% contained
37.0 miHigh Lava N2,899 acres · 95% contained

Pack this regardless

  • N95 or KN95 respirators, two per person — not cloth or surgical masks
  • One portable HEPA air purifier sized for the main room, plus a spare filter
  • A box fan and a 20x20 MERV-13 furnace filter with tape, as a cheap second purifier
  • Inhalers and any asthma or cardiac medication, in carry quantity not single doses
  • A real indoor plan for one full day — cards, board games, a projector or laptop and a download
  • An AQI app installed before leaving cell coverage (AirNow, OregonAir, or Watch Duty)

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

  • What the monitor actually recorded at Multorpor/Government Camp on Aug 28-30, 2026 — this replaces the whole estimate above - Any 24-hour PM2.5 AQI above 100 on those dates means the bad path actually happened (https://www.airnow.gov/ (Historical Air Quality) or Oregon DEQ AQI archive at https://oraqi.deq.state.or.us/)
  • Wind direction at Welches / Government Camp (only meaningful for a re-dated future trip) - Forecast wind from E, ESE, or SE for two consecutive days (NWS Portland point forecast for 45.32 N, -121.96 W)
  • Oregon DEQ air quality advisories for the Mt Hood corridor - Any advisory naming Clackamas County foothills or the Hood River / Mt Hood area (https://www.oregon.gov/deq/ and the OregonAir app)
  • Containment trajectory on fires within 20 miles - Containment on a fire inside 20 miles falling, or acreage jumping more than 20% day over day (https://inciweb.wildfire.gov/ and Watch Duty app)
  • New ignitions closer than the current fires - Any new fire west of the Cascade crest within 25 miles of Welches (Watch Duty app, or FIRMS satellite hotspots at https://firms.modaps.eosdis.nasa.gov/)
Sandy19.4 mi
Brightwood15.5 mi
Welches14.8 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
Welches / Mt Hood booked20 / 158 ClearGood– steady14 mi · The Narrows
Newport coast20 / 1713 ClearGood– steady101 mi · Austin
Astoria coast25 / 2219 ClearGood– steady84 mi · High Lava
Long Beach, WA coast25 / 2219 ClearGood– steady97 mi · High Lava
Manzanita coast26 / 2433 Clear—– steady87 mi · High Lava
Cannon Beach coast28 / 2433 Clear—– steady88 mi · High Lava
Pacific City coast29 / 2633 Clear—– steady91 mi · The Narrows
Hood River east of crest40 / 2618 ClearGood▲ worsening21 mi · Grasshopper
McMinnville valley45 / 3244 ClearGood– steady54 mi · The Narrows
Portland valley46 / 3759 HazyGood– steady36 mi · High Lava
Silver Falls valley49 / 3625 Clear—– steady31 mi · Austin
Bend east of crest56 / 3333 Clear—▼ clearing35 mi · Crosswhite
What each column covers, and where it comes from
FieldPeriod it coversWhat it is
Air right now10/12/26 4:00 PDTNearest EPA/AirNow ground monitor to each place, within 45 miles
airnow.gov
Official forecastissued 10/12/26 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 2026-10-16Direction 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, 2026-09-24 to 2026-10-07Median of daily model-vs-monitor ratios — the bias differs by place, from 0.37 on the coast to 0.694 inland
AirNow daily archive
Nearest firequeried Oct 12 5:01 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 27, 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 290 scored forecast-days, the air-quality model beat both simple baselines at 1 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 computed as a 24-hour average concentration, taking for each calendar day the highest 24-hour AQI value that touches that day, at the house at 45.3201 N, -121.9561 W in Mt Hood Village/Welches, Oregon — and then reporting the single worst such day across the three trip days, not the three-day average. All numbers are on the local monitor scale that a phone app displays, already calibrated from the raw model scale by the factor of 0.244 given in the pack; I applied no additional bias correction of my own.”

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