Keep the trip, but plan for the weekend to smell like a campfire at least part of the time. Two significant fires are burning within twenty miles of the house — one east of Mt Hood and one south of you on the same side of the mountain — and neither will be out by the end of August, so the whole question is which way the wind blows that weekend.
Our central guess is a hazy Moderate weekend, worst day near 70, with about a 28% chance that one day climbs past 100, which is the level where anyone with asthma should stay indoors with a filter running.
If we ran this weekend 100 times, here is how they would split. Hover a row to pick it out of the dots.
| 2 in 1023% | Clear weekend AQI 0-50 Mt Hood visible and sharp from the Salmon River, blue sky, maybe a faint campfire smell at dawn that burns off by nine. Nobody thinks about air. | nothing |
| 5 in 1046% | Hazy but fine AQI 50-100 Milky white sky, the ridgelines soften, sunsets go orange, and there is a persistent woodsmoke smell — strongest at sunrise and after dark when cold air sinks into the valley. Healthy adults hike fine; a couple of people get scratchy eyes. | Run a purifier in the main room, do the long hikes before noon, sleep with windows shut. |
| 2 in 1019% | One smoky day AQI 100-150 You cannot see Mt Hood at all from the driveway; the far side of the golf course goes gray. Smoke smell indoors. Sensitive people cough. The Multorpor and Government Camp monitors on your phone are orange. | Move that day indoors, N95s for anyone going out, purifiers running continuously, no strenuous hiking. |
| 1 in 1013% | Real smoke episode AQI 150+ Brown-orange light at midday, visibility down to a mile or two, ash flecks on car hoods, headaches by afternoon. It stings to breathe outside. Air quality alerts and possibly a Level 1 evacuation notice somewhere in the corridor. | Anyone with asthma, pregnancy, or heart issues should leave. The rest either shelter with filtration for the duration or drive out to the coast. |
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), Ten Mile (4,834 acres, 56.7 mi SE), Beachcomb (2,346 acres, 49.5 mi SSE), High Lava (1,251 acres, 38.8 mi NNW).
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 11 · Austin Aug 12 · Mitchell Aug 9. The oldest is Mitchell, 6 days behind. Acreage and containment are refreshed far more often than the outlines are re-flown — those figures were last updated Aug 15, 5:08 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.
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.
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 (+29 on the likely worst day) across 7 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 |
| Aug 22 | Air-quality / smoke model (CAMS) actual AQI at the house · reaches 6 days out |
Two things set the floor here and two set the ceiling. The floor: Grasshopper (87,820 acres, 37% contained, 17 mi east) and Austin (2,016 acres, 0% contained, 19 mi south) will still be producing smoke on the trip dates — Oregon fires this size do not go out in August, they end with September or October rain — and the current reading of 58 at Multorpor under dead-calm, foggy conditions proves that even with no transport wind at all, nighttime drainage and valley inversions pool their smoke in the Sandy River corridor. The ceiling: Welches sits on the marine-influenced west slope, and the dominant late-August regime is onshore westerly flow that pushes crest smoke east, which is why the 2022-2025 archive shows a 34 median and never exceeded 63 in this window. I am explicitly not crediting terrain shielding: Mt Hood is a cone that air flows around, not a wall, and Mitchell, Austin, and McCully Mountain are on the same west side of the crest as the house anyway. The bad case is a specific, nameable pattern rather than vague tail risk — a Great Basin ridge turning the Cascade gradient offshore, which simultaneously fans Austin and drives Grasshopper's plume downslope into the valley under a capping inversion. Over 12 days at national Preparedness Level 5 with fully cured fuels and constrained initial attack, a new ignition closer than the current ones is a live possibility, and that plus a four-year archive that has never seen a 2020-style year is why my p90 sits at 165 rather than at the climatological 108.
A normal late August here is Clear - median AQI 34 across the last 4 years. On these exact dates: 2025: 44 · 2024: 28 · 2023: 30 · 2022: 31.
We are forecasting a worst day of 71, 37 points above that base rate. That departure rests entirely on the reasoning above; judge it for yourself.
| 12.5 mi | Mitchell S | 16 acres |
| 17.4 mi | Grasshopper E | 87,820 acres · 37% contained |
| 19.4 mi | Austin S | 2,016 acres · 0% contained |
| 20.4 mi | Austin Non-Stat S | size not yet reported |
| 38.8 mi | High Lava NNW | 1,251 acres · 8% contained |
| 45.5 mi | Bench SSE | 67,071 acres · 86% contained |
| 49.5 mi | Beachcomb SSE | 2,346 acres · 100% contained |
The biggest hole in this forecast: 1 of the nearby fires (Austin Non-Stat) 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 | 22.8 mi |
| Brightwood | 17.5 mi |
| Welches | 14.3 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 | 16 Clear | Good | ▲ worsening | 105 mi · Austin |
| Manzanita coast | 22 / 21 | 24 Clear | Good | ▲ worsening | 87 mi · High Lava |
| Cannon Beach coast | 23 / 20 | 24 Clear | Good | ▲ worsening | 88 mi · High Lava |
| Pacific City coast | 23 / 20 | 24 Clear | Good | ▲ worsening | 98 mi · Austin |
| Astoria coast | 26 / 23 | 17 Clear | Good | ▲ worsening | 84 mi · High Lava |
| Long Beach, WA coast | 27 / 24 | 17 Clear | Good | ▲ worsening | 97 mi · High Lava |
| Welches / Mt Hood booked | 37 / 28 | 40 Clear | Sensitive groups | – steady | 17 mi · Grasshopper |
| Silver Falls valley | 45 / 33 | 25 Clear | Moderate | ▲ worsening | 35 mi · Austin |
| Portland valley | 48 / 38 | 32 Clear | Moderate | – steady | 36 mi · High Lava |
| McMinnville valley | 53 / 37 | 23 Clear | Moderate | ▲ worsening | 61 mi · Austin |
| Bend east of crest | 119 / 70 | 54 Hazy | Moderate | – steady | 22 mi · Akawa Butte |
| Hood River east of crest | n/a | 46 Clear | Sensitive groups | – steady | 21 mi · Grasshopper |
| Field | Period it covers | What it is |
| Air right now | 08/16/26 4:00 PDT | Nearest EPA/AirNow ground monitor to each place, within 45 miles airnow.gov |
| Official forecast | issued 08/16/26 by Oregon Dept. of Environmental Quality | Next published outlook for that reporting area — a human forecaster's call Oregon DEQ via AirNow |
| Next 5 days | today's model run, covering 2026-08-20 | 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, 2026-07-31 to 2026-08-13 | Median 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 fire | queried Aug 16 5:01 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 (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 63, 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? Accuracy checking started Aug 13. 6 forecast-days scored so far — far too few to claim anything. This is the only part of the page that can ever be proved wrong.
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 AQI for PM2.5 at the Welches house — a 24-hour-average quantity, taking the highest 24-hour AQI value touching each calendar day, on the local monitor scale that a phone app would display (the same scale as the Multorpor station's current 58, not the raw model scale). I report each of the three trip days and, as the headline number, the single worst of Aug 28, 29, and 30. I applied no bias correction of my own; the evidence pack's values were already calibrated.”
Updated daily at 5am. A convenience, not an authority -
if officials issue an evacuation order, follow it.