First, a flag the group should see: the dates being asked about are about eight weeks in the past, so this is a reconstruction of what the air most likely did, not a live forecast. The most probable outcome for that weekend at the Welches house was ordinary late-summer haze — noticeable in the valley in the morning, not a reason to cancel.
The real risk was narrower: a stretch of east wind pulling smoke from the big Grasshopper fire, 17 miles east, down over Government Camp and into the Zigzag valley for a day, which would have made one day genuinely unpleasant for anyone with asthma.
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 1041% | Clear weekend AQI 0-50 Mt Hood sharp against blue sky from the Welches meadow, maybe a thin morning valley fog that burns off, cool onshore breeze by afternoon, no smell of smoke. | nothing |
| 3 in 1034% | Hazy but fine AQI 50-100 Milky white sky, the mountain's outline soft, a faint campfire smell at dawn that fades by midday; sunsets unusually orange. Everyone fine except maybe one sensitive person. | Keep strenuous hikes to the morning, run a purifier in the bedroom where anyone with asthma sleeps, close windows overnight instead of sleeping with them open. |
| 1 in 1015% | One smoky day AQI 100-150 You can't see Mt Hood at all. Ridgelines across the valley go flat gray, the sun is a dull orange disc by midday, smoke smell indoors, eyes itch. Phone app reads orange all day. | That day becomes an indoor day — swap the hike for Timberline Lodge drive-up or a Portland run, N95s for anyone outside more than a few minutes, purifier running in the main room, kids and anyone with lung issues stay in. |
| 1 in 1011% | Real smoke episode AQI 150+ Visible smoke layer in the trees, headaches and sore throats across the group within hours, smoke seeping into the house no matter what you close, air app red for 24+ hours straight, possible Level 1 'Be Ready' notice somewhere in the Hoodland corridor. | Cut the trip short or relocate west toward the coast; anyone with asthma, anyone pregnant, and any small kids should leave rather than wait it out. |
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.
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, 36 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.
Long-range wind signal unavailable this run.
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.
▲ Since 2026-08-10 the forecast has moved worse (+24 on the likely worst day) across 72 daily updates. Shading above shows source coverage, not this movement - hover a past day to see what we said that morning.
| now | Fire size & containment how big the fires are and whether they are being held |
| now | Long-range ensembles (GEFS 0.5 + GEM) wind direction, 52 members · reaches 32 days out |
| now | ECMWF ensemble (51 members) wind direction, the sharpest ensemble · reaches 13 days out |
| now | Deterministic weather (16-day) day-by-day wind and temperature · reaches 15 days out |
| now | Air-quality / smoke model (CAMS) actual AQI at the house · reaches 6 days out |
The mechanism here is a one-way valve. Every significant fire in the evidence except the 304-acre, 98%-contained Narrows sits east or southeast of the house, on the far side of an 11,250-foot ridge, and the default late-August circulation on the west slope is onshore marine flow that pins that smoke on the east side — so most days the house simply cannot see it. The bad case requires a specific, common-but-not-typical pattern: an offshore gradient turning flow easterly, after which nighttime downslope drainage funnels Grasshopper's smoke straight down the Barlow/Government Camp corridor into the Zigzag valley and pools it under an inversion, which is precisely how the 24-hour average — not a brief hourly spike — gets above 100. That path needed about 31% of days to be offshore and the fires to still be smoking; both were plausible in late August but neither was guaranteed, and I have no ensemble signal to sharpen it because that field is null. Pushing me up: a record 2.34M-acre state season, 96% drought, record-low snowpack, PL-5 resource constraints that make initial attack on a new nearby ignition slower, and the genuine possibility of a fresh start west of the crest inside a long lead time. Pushing me down: all four major fires were at 90–100% containment, the nearest fire of any kind is tiny, the 28-day historical sample in this exact window has never produced a day over 100 with a worst-ever of 82, and the measured local season anomaly is 1.02 — this year's severity has been overwhelmingly east-side acreage that does not transport to this address.
A normal late August here is Clear - median AQI 44 across the last 4 years. On these exact dates: 2025: 57 · 2024: 37 · 2023: 39 · 2022: 40.
We are forecasting a worst day of 66, 22 points above that base rate. That departure rests entirely on the reasoning above; judge it for yourself.
| 13.9 mi | The Narrows SSW | 304 acres · 98% contained |
| 17.4 mi | Grasshopper E | 93,971 acres · 98% contained |
| 18.3 mi | Austin S | 12,888 acres · 98% contained |
| 37.0 mi | High Lava N | 2,899 acres · 100% contained |
| 44.1 mi | Muddy Run RX SSE | size not yet reported |
| 45.5 mi | Bench SSE | 67,071 acres · 90% contained |
| 55.0 mi | Wikstrom Rd #2 NW | size not yet reported |
The biggest hole in this forecast: 2 of the nearby fires (Muddy Run RX, Wikstrom Rd #2) have no size reported yet. Whether those are 300-acre creepers or 20,000-acre runners is most of the answer.
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.
| Sandy | 19.4 mi |
| Brightwood | 15.5 mi |
| Welches | 14.8 mi |
Distance from each point on the drive in to the nearest fire. TripCheck is the authority on closures.
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.
| Place | Bad day / typical | Now | Official forecast | Next 5 days | Nearest fire |
| Newport coast | 20 / 17 | 30 Clear | Good | – steady | 101 mi · Austin |
| Astoria coast | 21 / 18 | 23 Clear | Good | – steady | 84 mi · High Lava |
| Long Beach, WA coast | 22 / 19 | 23 Clear | Good | – steady | 97 mi · High Lava |
| Welches / Mt Hood booked | 23 / 17 | 30 Clear | Good | ▲ worsening | 14 mi · The Narrows |
| Manzanita coast | 29 / 27 | 51 Hazy | — | – steady | 87 mi · High Lava |
| Cannon Beach coast | 31 / 27 | 51 Hazy | — | – steady | 88 mi · High Lava |
| Pacific City coast | 31 / 28 | 51 Hazy | — | – steady | 91 mi · The Narrows |
| Hood River east of crest | 42 / 28 | 36 Clear | Good | – steady | 21 mi · Grasshopper |
| Portland valley | 47 / 38 | 66 Hazy | Good | – steady | 36 mi · High Lava |
| Silver Falls valley | 53 / 39 | 54 Hazy | — | – steady | 31 mi · Austin |
| McMinnville valley | 55 / 38 | 63 Hazy | Good | – steady | 54 mi · The Narrows |
| Bend east of crest | 58 / 34 | 50 Clear | — | – steady | 36 mi · Bench |
| Field | Period it covers | What it is |
| Air right now | 10/21/26 4:00 PDT | Nearest EPA/AirNow ground monitor to each place, within 45 miles airnow.gov |
| Official forecast | issued 10/21/26 by Washington Department of Ecology | Next published outlook for that reporting area — a human forecaster's call Oregon DEQ via AirNow |
| Next 5 days | today's model run, covering 2026-10-25 | Direction only. Copernicus CAMS global air-quality model open-meteo.com |
| Bad day / typical | Aug 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 conversion | median of 14 daily model-vs-monitor pairs, 2026-10-01 to 2026-10-14 | Median 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 fire | queried Oct 21 5:00 AM | Perimeter 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.
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 82, 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 335 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 one number: the highest 24-hour-average US AQI for PM2.5 that touches any one of August 28, 29 or 30, 2026, at the house in Mt Hood Village/Welches — the worst single day, not the three-day mean. It is on the local monitor scale, the value a phone weather or AirNow app would display, already bias-corrected from the raw CAMS model scale by the 0.735 factor given in the evidence, so I have applied no further correction of my own. Because the quantity is a 24-hour average, a two-hour surge of thick smoke at 3am does not by itself put the day over 100; the smoke has to persist most of a day, which is exactly why the overnight valley inversion matters so much to the bad case.”
Updated daily at 5am. A convenience, not an authority -
if officials issue an evacuation order, follow it.