Yellowstone National Park wildfire smoke forecast
The map above shows NOAA HRRR-Smoke near-surface PM2.5 for the next 48 hours, updated hourly, with active fires from NIFC and live AQI from EPA AirNow monitors. It opens over Yellowstone National Park.
Yellowstone is a high volcanic plateau mostly between 7,500 and 8,000 feet, cut by broad valleys such as the Lamar, Hayden, and Madison. The plateau ventilates reasonably well, but those valleys pool cold air and smoke overnight, which puts the densest air of the day exactly where and when most visitors are out looking for wildlife.
Where the smoke comes from
Fires within the Greater Yellowstone area supply the sharpest smoke, and transport from Idaho and western Montana supplies most of the rest. August and early September are the peak, and the park's remoteness means large fires are often managed rather than suppressed, so smoke can persist through a season.
How long it lasts
Valley pooling breaks up within a few hours of sunrise as the plateau heats. Regional transport smoke is a different problem and lifts only with a change in the larger pattern. A morning that starts thick in Lamar is often clear by mid-morning; a week of regional haze is not.
Past smoke events
The 1988 fires burned roughly 36 percent of the park and remain the defining event. The 2016 Maple Fire and the 2021 season both produced extended late-summer smoke across the park.
Trails and viewpoints
Dawn in the Lamar and Hayden valleys is the classic wildlife-watching window and the worst hour for pooled smoke. The geyser basins sit on the open plateau and clear earlier. Backcountry trips over multiple days are worth planning against the 48-hour outlook rather than the current reading at the entrance.
Reading the map
Use the layer toggle to compare NOAA HRRR-Smoke with the ECCC FireWork model. When the two disagree, treat the higher reading as the cautious call.
Near-surface is the product that maps to what you breathe and to AQI, not the high-altitude column that only tints the sunset. A sky that looks bad and a monitor that reads fine are usually both correct, and they are describing different layers of air.