The biggest fire near the house sits behind Mt Hood, and the wind patterns forecast for that weekend blow its smoke away from you rather than toward you. What you should actually plan on is a valley that smells like a campfire at breakfast and clears through the afternoon — annoying, not trip-ending.
The realistic bad case is a single day in the unhealthy-for-sensitive-groups range, driven not by Mt Hood but by two uncontained fires about fifteen miles due south of the house, on your side of the mountains.
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 1027% | Clear weekend AQI 0-50 Mt Hood sharp against blue sky all three days, no smell, kids outside from morning on. | nothing |
| 5 in 1049% | Hazy but fine AQI 50-100 Milky-white sky, faint campfire smell at 7am that burns off by 11, the mountain visible but soft-edged, ridgelines a few miles off look flat and gray. Nobody's eyes water; one asthmatic in the group notices. | Nothing structural — sleep with windows shut, do the long hike in the afternoon rather than at dawn. |
| 1 in 1015% | One smoky day AQI 100-150 One morning the far side of the valley is a silhouette, sun is orange at 10am, air stings slightly in the throat. Other two days are merely hazy. | Swap that day's outdoor plan for indoors — run a HEPA purifier in the main room, wear N95s for the drive/errands, keep the kids and anyone with asthma inside until evening. |
| 1 in 109% | Real smoke episode AQI 150+ Ash flecks on the car, visibility under a mile, smoke smell indoors even with windows shut, headaches by afternoon, everyone's phone showing purple. | Leave early or relocate west toward the coast; check Clackamas County evacuation levels and Watch Duty before driving anywhere on US-26. |
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 (1,405 acres, 37.8 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 Aug 18 · Austin Aug 18 · The Narrows Aug 18 · Mitchell Aug 16. The oldest is Mitchell, 2 days behind. Acreage and containment are refreshed far more often than the outlines are re-flown — those figures were last updated Aug 19, 3:51 AM, 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 (+17 on the likely worst day) across 10 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 |
The instinct here is to worry about Grasshopper — 92,399 acres, 17 miles east — but Mt Hood and the Cascade crest sit between it and the house, and getting its smoke to Welches requires sustained easterly downslope flow; the ensembles put that at 10% of member-days versus a 31% climatological rate for this window, a 21-point negative departure that is real evidence against exactly the mechanism the bad case needs. The fires that can actually reach this house without any wind reversal are the ones people overlook: Mitchell (12.5 mi S), The Narrows (14 mi SSW, 0% contained), and Austin (19 mi S, 0% contained) are at essentially the same longitude as the house, west of the crest, in the drainage that feeds north toward the Sandy/Zigzag corridor — no terrain shielding at all. Under the prevailing onshore westerly pattern their smoke is flushed east and the house stays clean-to-hazy, which is why the modal outcome is 50-100; the failure mode is a southerly ahead of a front or a stagnant ridge, combined with normal overnight valley drainage that pools smoke at the house between 2am and 10am and drags the 24-hour average up even when afternoons look fine. The nearby monitor already reads 52 today with no east wind, which is a fair picture of the current steady state, so a worst-day median of 57 is close to 'today, repeated' rather than a forecast of deterioration.
A normal late August here is Clear - median AQI 19 across the last 4 years. On these exact dates: 2025: 25 · 2024: 16 · 2023: 17 · 2022: 17.
We are forecasting a worst day of 59, 40 points above that base rate. That departure rests entirely on the reasoning above; judge it for yourself.
| 12.5 mi | Mitchell S | 16 acres |
| 14.0 mi | The Narrows SSW | 160 acres · 0% contained |
| 17.4 mi | Grasshopper E | 92,399 acres · 57% contained |
| 19.0 mi | Austin S | 3,244 acres · 0% contained |
| 20.4 mi | Austin Non-Stat S | size not yet reported |
| 37.8 mi | High Lava N | 1,405 acres · 8% contained |
| 45.5 mi | Bench SSE | 67,071 acres · 90% 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 | 19.4 mi |
| Brightwood | 15.6 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 | 17 Clear | Good | – steady | 102 mi · The Narrows |
| Manzanita coast | 22 / 21 | 26 Clear | Good | – steady | 87 mi · High Lava |
| Cannon Beach coast | 23 / 20 | 26 Clear | Good | – steady | 88 mi · High Lava |
| Pacific City coast | 23 / 20 | 26 Clear | Good | – steady | 91 mi · The Narrows |
| Astoria coast | 26 / 23 | 12 Clear | Good | – steady | 84 mi · High Lava |
| Long Beach, WA coast | 27 / 24 | 12 Clear | Good | – steady | 97 mi · High Lava |
| Welches / Mt Hood booked | 37 / 28 | 57 Hazy | Moderate | – steady | 14 mi · The Narrows |
| Silver Falls valley | 45 / 33 | 55 Hazy | Moderate | – steady | 33 mi · The Narrows |
| Portland valley | 48 / 38 | 36 Clear | Good | – steady | 36 mi · High Lava |
| McMinnville valley | 53 / 37 | 40 Clear | Good | – steady | 54 mi · The Narrows |
| Bend east of crest | 119 / 70 | 126 Smoky | Moderate | ▲ worsening | 22 mi · Akawa Butte |
| Hood River east of crest | n/a | 53 Hazy | Sensitive groups | – steady | 21 mi · Grasshopper |
| Field | Period it covers | What it is |
| Air right now | 08/19/26 4:00 PDT | Nearest EPA/AirNow ground monitor to each place, within 45 miles airnow.gov |
| Official forecast | issued 08/19/26 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 2026-08-23 | 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 19 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 (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 36, 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 20 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 — the single highest such 24-hour value touching each calendar day — at the house in Welches, Oregon, reported on the local monitor scale, i.e. the number a phone app like AirNow would display, already calibrated from the raw model output. I have applied no additional bias correction. 'Worst day of trip' means the maximum of that quantity across August 28, 29, and 30, not the three-day average.”
Updated daily at 5am. A convenience, not an authority -
if officials issue an evacuation order, follow it.