A very large fire was still burning about 17 miles straight east of the house over your dates, and Mount Hood is a cone, not a wall — east wind or overnight canyon drainage can carry that smoke down the Sandy/Zigzag valley right to Welches. Most late-August days there are onshore and clean, so the single most likely weekend is clear-to-slightly-hazy with worst-day AQI around 85 and smoky mornings that clear by afternoon.
One important caveat: these dates are already in the past relative to the evidence I was handed (it was collected 2026-10-29), and the east-wind ensemble field came back empty, so I am reasoning from climatology plus fire geometry rather than from any actual forecast for those three days.
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 1037% | Clear weekend AQI 0-50 Mt Hood sharp and blue all three days, cool damp mornings, no smell of smoke, phone app reads teens to 40s. | nothing |
| 4 in 1039% | Hazy but fine AQI 50-100 Milky white sky, the mountain soft-edged, a faint campfire smell at dawn in the river valley that burns off by 11am; sunsets orange. | Do the hike in the morning or afternoon rather than at dawn; keep windows shut overnight. |
| 1 in 1014% | One smoky day AQI 100-150 One day where the ridge across the river is a gray silhouette, visibility a couple of miles, eyes and throat scratchy outdoors, kids and anyone with asthma noticeably bothered. | That day becomes indoors-with-a-box-fan-filter: cards, the pool if indoors, a drive west to Sandy or Portland where it is usually cleaner. |
| 1 in 1010% | Real smoke episode AQI 150+ Brown-orange daylight, the mountain invisible, smoke indoors, headaches by evening; everyone talking about leaving. | Leave a day early, or relocate the group west of Sandy; this is the only scenario where the trip is actually spoiled. |
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: 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 oldest is Grasshopper, 44 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 (+16 on the likely worst day) across 80 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 controlling fact is geometry: Grasshopper's western perimeter sits at roughly -121.60/45.28-45.31, which is east of Mount Hood's longitude but only about four miles east of Barlow Pass, and the Salmon/Zigzag drainage runs from there straight down to Welches — so the house is not meaningfully shielded by terrain, it is at the bottom of a chute from the fire's nearest flank. A fire that reached 93,971 acres with a mid-September perimeter was almost certainly at or near peak activity on August 28-30, so smoke supply was real; what rationed it was wind direction, and the climatological 31% offshore rate in this window (no ensemble was supplied, so I cannot claim a departure in either direction and have not invented one) means roughly one trip day in three had an easterly component, with overnight valley drainage able to deliver smoke even on otherwise onshore days. Pushing the other way, late August on the Cascades' west slope is dominated by marine onshore flow, the 28-day empirical record at this location has never exceeded 100 and tops out at 67, and both nearby fires ended up at 98% containment — which is why my median worst day is 85 rather than in the hundreds. I fatten the upper tail deliberately: the archive starts in 2022 and has therefore never sampled a 2020-class event, the climatology's own p90 of 133 contradicts its 28-day maximum of 67, and the record-acreage, fully-cured-fuel, PL-5 season raises the odds of a new ignition on the west side during the long lead time, which is the one path to a genuinely ruined weekend.
A normal late August here is Clear - median AQI 36 across the last 4 years. On these exact dates: 2025: 47 · 2024: 30 · 2023: 32 · 2022: 32.
We are forecasting a worst day of 58, 22 points above that base rate. That departure rests entirely on the reasoning above; judge it for yourself.
| 16.2 mi | Clear Lake Pile Rx-East SE | size not yet reported |
| 16.5 mi | Fawn Stew Piles Rx - West SSW | size not yet reported |
| 17.4 mi | Grasshopper E | 93,971 acres · 98% contained |
| 18.3 mi | Austin S | 12,888 acres · 98% contained |
| 25.7 mi | Skid SE | size not yet reported |
| 26.3 mi | Spike Timber Sale Rx - West SSE | size not yet reported |
| 32.4 mi | Triple Butte RX SSE | size not yet reported |
The biggest hole in this forecast: 5 of the nearby fires (Clear Lake Pile Rx-East, Fawn Stew Piles Rx - West, Skid and 2 more) 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 | 23.2 mi |
| Brightwood | 19.2 mi |
| Welches | 17.8 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 |
| Astoria coast | 19 / 16 | 12 Clear | Good | ▲ worsening | 84 mi · High Lava |
| Long Beach, WA coast | 19 / 17 | 12 Clear | — | ▲ worsening | 97 mi · High Lava |
| Newport coast | 25 / 21 | 33 Clear | Good | ▲ worsening | 101 mi · Austin |
| Welches / Mt Hood booked | 30 / 22 | 20 Clear | Good | ▲ worsening | 17 mi · Grasshopper |
| Manzanita coast | 30 / 28 | 61 Hazy | — | ▲ worsening | 87 mi · High Lava |
| Cannon Beach coast | 31 / 27 | 61 Hazy | — | ▲ worsening | 88 mi · High Lava |
| Pacific City coast | 32 / 29 | 61 Hazy | — | ▲ worsening | 93 mi · Austin |
| Hood River east of crest | 46 / 30 | 22 Clear | Good | ▲ worsening | 21 mi · Grasshopper |
| Silver Falls valley | 50 / 37 | 37 Clear | — | ▲ worsening | 31 mi · Austin |
| Portland valley | 67 / 54 | 34 Clear | Good | ▲ worsening | 36 mi · High Lava |
| McMinnville valley | 76 / 53 | 28 Clear | Good | ▲ worsening | 57 mi · Austin |
| Bend east of crest | 78 / 45 | 41 Clear | — | ▲ worsening | 70 mi · Austin |
| Field | Period it covers | What it is |
| Air right now | 10/29/26 4:00 PDT | Nearest EPA/AirNow ground monitor to each place, within 45 miles airnow.gov |
| Official forecast | issued 10/29/26 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 2026-11-02 | 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, 2026-10-09 to 2026-10-22 | Median of daily model-vs-monitor ratios — the bias differs by place, from 0.351 on the coast to 1.066 inland AirNow daily archive |
| Nearest fire | queried Oct 29 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 67, 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 375 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 at the house in Welches (45.3201, -121.9561) — a 24-hour-average quantity — taking for each calendar day the highest 24-hour AQI value touching that day, and then reporting the single worst of the three trip days (Aug 28, 29, 30). All numbers are on the local monitor scale that a phone app would display, already calibrated; I applied no further bias correction of my own.”
Updated daily at 5am. A convenience, not an authority -
if officials issue an evacuation order, follow it.