Mt Hood · Aug 28-30 · -55 days out Updated Thu Oct 22, 5:00 AM · refreshes daily at 5am

Everything is fine.

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

First, a flag you should know about: the weekend you asked about is in the past — August 28-30 was 55 days before the data in this pack, and every live observation here (a frost advisory, light rain, fires at 90-98% contained) describes mid-October, not late August. Treating it as a genuine forecast made with late-August information, the most likely outcome at the house was a Moderate, slightly hazy weekend with a worst day around 57 on the monitor scale — noticeable in the sky and on the horizon, fine for hiking and sitting outside.

The real risk was not the average but a single bad day: roughly a 1-in-3-to-1-in-4 chance that one of the three days crossed 100, driven by an east-wind reversal or nighttime drainage off the two fires burning south of you on your own side of the mountains.

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 Estacada35 · 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.

3 in 1034%Clear weekend AQI 0-50
Mt Hood sharp-edged all three days, blue sky to the ridgelines, cool damp mornings off the marine layer, no smell of smoke on the deck at night.
nothing
4 in 1038%Hazy but fine AQI 50-100
Milky white sky, the far ridges flattened into gray layers, an orange-ish sunset, a faint campfire smell in the valley at dawn that burns off by 10am. Nobody's eyes hurt; the group still hikes.
Shift the long hike to the morning, run the AC on recirculate in the cars, keep windows shut overnight.
2 in 1017%One smoky day AQI 100-150
One day you can't see Hood at all from the Village, visibility down to a couple of miles down US-26, sun a dull disc, throats scratchy by afternoon. The other two days are merely hazy.
Indoor day: board games, Sandy or Portland for the afternoon, box-fan filter in the main room, anyone with asthma stays in.
1 in 1011%Real smoke episode AQI 150+
Brown-gray air at ground level, ash flecks on car hoods, headlights on at midday, a sore throat within an hour outside. Possible Level 1 'be ready' notices in the Hoodland corridor.
Leave early or don't come. This is the case where the trip is not worth it for anyone with a kid, a pregnancy, or a lung condition.
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 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 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 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 milesGrasshopperBenchAustinHigh LavaThe Narrows407 DetMuddy Run RXTule RXWikstrom Rd #2Wapato NWR- Beecher Unit RXSummit
SandyBrightwoodWelchesGovernment Campan east wind would carry smoke from here20 mi40 miThe houseGrasshopper93,971 acres · 17.4 miBench67,071 acres · 45.5 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: Bench (67,071 acres, 45.5 mi SSE), 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, 37 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 47 - could reach 120
13% chance of a smoky day
Sat Aug 29
Clear
likely 48 - could reach 124
14% chance of a smoky day
Sun Aug 30
Clear
likely 47 - could reach 122
14% chance of a smoky day

The specific odds

All three days clear32%
At least one smoky day (100+)27%
Two or more smoky days15%
At least one bad day (150+)11%
US-26 closed during the trip2%
Evacuation level at Welches6%

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 (+21 on the likely worst day) across 73 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 house sits on the west slope at 1,200 feet in the Zigzag/Sandy valley, and in late August the default pattern is onshore: a nightly marine push ventilates the west Cascade slope and carries smoke east over the crest, which is why 28 sampled days in this calendar window produced zero days over 100 and a worst observed day of 68. But the terrain argument is weaker here than it looks — I checked the bearings, and Austin (12,888 acres, bearing S) and The Narrows (bearing SSW) are both on the WEST side of the crest, upriver in the Clackamas drainage, so Mt Hood shields the house from neither; only Grasshopper at bearing 207... correction, Grasshopper at bearing E needs to cross the crest. That gives two mechanisms rather than one: a genuine offshore reversal (31% of member-days climatologically in this window, and with a null ensemble I have no evidence to push that lower) bringing Grasshopper's 94,000-acre column over the top, or merely light southerly/nocturnal drainage flow funneling Austin's smoke down the Clackamas-to-Sandy corridor into a valley that inverts hard overnight — and because the AQI is a 24-hour average, overnight pooling matters as much as the afternoon. Against that: the measured season anomaly is 1.02, essentially neutral, and the pack explicitly tells me not to stack a 'record year' multiplier on top of it, since Oregon's 2.34 million acres are dominated by east-side fires that never transport to this address.

A normal late August here is Clear - median AQI 37 across the last 4 years. On these exact dates: 2025: 48 · 2024: 31 · 2023: 33 · 2022: 33.

We are forecasting a worst day of 63, 26 points above that base rate. That departure rests entirely on the reasoning above; judge it for yourself.

What the bad version needs:
The thermal trough shifts east of the Cascades and a surface high builds over the Great Basin, reversing the Portland-to-Bend gradient to offshore (easterly) — the 31% climatological rate for this calendar window, with no ensemble forecast in this pack to argue it down. → Easterly flow pushes the Grasshopper fire's column (93,971 acres, 17.4 mi due east) up and over the crest near Hood River / Badger Creek, while the same dry east wind re-energizes open line on Austin (12,888 acres, 18.3 mi south) and The Narrows — both of which sit on the WEST side of the crest, the same side as the house, so no terrain shields them at all. → Smoke subsides into the Zigzag/Sandy River valley and, with light winds and a strong nocturnal inversion, pools in the Welches basin overnight and through the following morning — the 24-hour average, not just the afternoon, clears 150.
First visible signal: Two to four days ahead, the NWS Portland forecast discussion starts using the phrase 'offshore gradient' or 'east wind event' and the Zigzag/Government Camp point forecasts flip their wind direction from W/NW to E/NE. On a phone, the first physical sign is the PurpleAir map: the Estacada and Sandy sensors turn yellow-to-orange a half-day before Welches does, because the valley fills from the south and east first. - about 3 days ahead
Key drivers, and what would change our minds
  • The east/offshore wind reversal is the whole forecast — and the ensemble field for the trip dates is NULL, so I am stuck with the 31% climatological offshore rate for this window with no departure signal either way.
  • Austin (12,888 ac, 18.3 mi S) and The Narrows (13.9 mi SSW) are on the house's own side of the Cascade crest; terrain does not shield the house from them, and they only need light southerly or nocturnal drainage flow, not a full reversal.
  • Grasshopper at 93,971 acres and 17.4 miles due east is the only fire big enough to make a 150+ day, but it needs smoke to clear the crest near Mt Hood — a high bar that basically requires a deep easterly gradient layer.
  • Containment of 90-98% is dated 2026-09-17, well after the trip; the fires were materially less contained on the actual trip dates and I have no figure for what they were.
  • Season anomaly ratio of 1.02 — measured in local AQI at this location — says this year has NOT so far manifested as unusual smoke at this address, and the pack forbids double-counting statewide acreage on top of it.
  • 28 days sampled in this window, 0% over 100, worst day 68 — real evidence for a benign central case, but from only four years (2022-2025) that exclude 2017, 2018, 2020 and 2021.
  • The Zigzag or Government Camp point forecast on weather.gov showing wind from the E or NE for any trip day — that alone moves me from GO_WITH_CONTINGENCY toward RECONSIDER.
  • The Estacada monitor on the AirNow app sitting above 75 for most of a day, or Sandy/Estacada PurpleAir sensors going orange — the valley fills from the south, so that is your early warning.
  • Any new fire appearing west of the crest between the Clackamas and the Sandy Rivers on the Watch Duty app, at any size.
  • Austin's containment percentage going DOWN, or its acreage jumping more than ~1,500 acres in one daily update.
  • A measurable soaking rain in the Mt Hood corridor in the week before the trip — half an inch basically ends the risk, and I would go to a near-flat GO.
  • Any Level 1 evacuation notice or Clackamas County air quality advisory naming the Hoodland corridor.

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 · 100% contained
44.1 miMuddy Run RX SSEsize not yet reported
45.5 miBench SSE67,071 acres · 90% contained
50.2 miTule RX ESEsize not yet reported

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

Pack this regardless

  • Two box fans plus four MERV-13 20x20 furnace filters and a roll of duct tape — a $60 DIY Corsi-Rosenthal box drops indoor PM2.5 by 80%+ and is the single highest-value thing you can bring to a rental you cannot re-filter.
  • A dozen N95 or KN95 respirators (not cloth, not surgical) — useless for comfort, decisive if you have to load cars in 200 AQI air.
  • Rescue inhalers and any allergy/asthma meds for everyone who uses them, plus spares — smoke triggers people who normally never need them.
  • Saline nasal spray and eye drops, and more drinking water than you think you need.
  • A plan B day: one indoor-friendly option in Sandy, Hood River or Portland that twelve people would actually enjoy.
  • Everyone's rental cancellation/refund deadline screenshotted in the group chat before anyone leaves home.

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

  • Portland-to-Bend (PDX-BDN) surface pressure gradient / any mention of 'offshore flow' or 'east wind' in the NWS Portland Area Forecast Discussion - Offshore gradient forecast for any trip day, or the Zigzag point forecast showing winds from E/NE/SE instead of W/NW — act on this, it is the single hinge of the whole forecast. (https://forecast.weather.gov/product.php?site=PQR&issuedby=PQR&product=AFD)
  • Ground-truth PM2.5 at and upwind of the house - Estacada or Sandy over 75 for six straight hours, or any Welches-area PurpleAir over 100 — the valley is next, usually within 12 hours. (PurpleAir map (map.purpleair.com) centered on Welches, plus the Estacada regulatory monitor on AirNow / the AirNow app)
  • Austin fire and The Narrows daily situation reports — these are the WEST-side fires, the ones terrain does not protect you from - Containment on Austin dropping, acreage growing more than ~1,500 acres in a day, or new uncontained line reported on its north or west flank. (inciweb.nwcg.gov and the Oregon ODF / Mt Hood National Forest fire pages)
  • New ignitions inside ~25 miles — the real wildcard at this lead time, with 96% of Oregon in drought and fuels fully cured - Any new named fire west of the crest between the Clackamas River and the Sandy River, regardless of reported size. (firms.modaps.eosdis.nasa.gov (VIIRS 24h hotspots) or the Watch Duty app, Clackamas/Hood River counties)
  • Evacuation notices for the Hoodland corridor (Welches, Wemme, Rhododendron, Brightwood) - Any Level 1 'Be Ready' touching the Hoodland corridor — change plans the same day, don't wait for Level 2. (Clackamas County Disaster Management / Public Alerts (publicalerts.org), Watch Duty app)
  • Smoke-specific outlook for the Mt Hood corridor - An Air Quality Advisory issued for Clackamas County or the Mt Hood corridor covering any trip day. (Oregon DEQ smoke blog (oregonsmoke.blogspot.com) and fire.airnow.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
Newport coast20 / 1753 HazyGood– steady101 mi · Austin
Astoria coast21 / 1821 ClearGood– steady84 mi · High Lava
Long Beach, WA coast22 / 1921 ClearGood– steady97 mi · High Lava
Welches / Mt Hood booked23 / 1734 ClearGood– steady14 mi · The Narrows
Manzanita coast29 / 2753 Hazy—– steady87 mi · High Lava
Cannon Beach coast31 / 2753 Hazy—– steady88 mi · High Lava
Pacific City coast31 / 2853 Hazy—– steady91 mi · The Narrows
Hood River east of crest42 / 2852 HazyGood– steady21 mi · Grasshopper
Portland valley47 / 3870 HazyGood▲ worsening36 mi · High Lava
Silver Falls valley53 / 3962 Hazy—– steady31 mi · Austin
McMinnville valley55 / 3866 HazyGood– steady54 mi · The Narrows
Bend east of crest58 / 3463 Hazy—– steady36 mi · Bench
What each column covers, and where it comes from
FieldPeriod it coversWhat it is
Air right now10/22/26 4:00 PDTNearest EPA/AirNow ground monitor to each place, within 45 miles
airnow.gov
Official forecastissued 10/22/26 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 2026-10-26Direction 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, 2026-10-01 to 2026-10-14Median of daily model-vs-monitor ratios — the bias differs by place, from 0.37 on the coast to 0.768 inland
AirNow daily archive
Nearest firequeried Oct 22 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 (Estacada, 18.3 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 68, 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 340 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 as a 24-hour average quantity — specifically the single highest 24-hour-average AQI value touching any one of the three calendar days 2026-08-28, 08-29 and 08-30, at the house in Mt Hood Village / Welches (45.320, -121.956), expressed on the local monitor scale that a phone app like AirNow would have displayed (the evidence pack already applied the 0.614 model-to-monitor factor, and I added no bias correction of my own). My headline number is the worst single day of the trip, not the three-day mean. One caveat on the scale itself: that 0.614 factor was fit at the Estacada monitor 18.3 miles away, not at the house, so there is unmodelled error in transferring it up the valley. And the honest caveat on the whole exercise: today is 2026-10-22 and these dates are 55 days in the past, so this is a hindcast of a weekend that has already happened, built from a pack whose live observations all describe October.”

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