Grand Teton 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 Grand Teton National Park.
Jackson Hole is a flat-floored valley at about 6,300 feet with the Teton Range rising more than 7,000 feet directly off its western edge and no foothills in between. It is a textbook cold-air pool: air drains off the range and off the surrounding highlands every clear night and settles on the valley floor, and the peaks routinely stand above the layer that fills the valley below them.
Where the smoke comes from
Idaho fires to the west, western Wyoming fires, and Great Basin transport are the usual suppliers, with fires inside the park and the Bridger-Teton forest producing the densest episodes. The valley is narrow enough that a single upwind fire can dominate its air for days.
How long it lasts
Morning heating mixes the valley layer out, generally later than on the Yellowstone plateau because the valley is deeper and more enclosed. Regional smoke lifts only with a pattern change, and the valley then reconcentrates whatever remains each night.
Past smoke events
The 2016 Berry Fire closed the John D. Rockefeller Jr. Memorial Parkway between the two parks, and the 2018 and 2021 seasons both filled Jackson Hole with regional smoke for extended stretches.
Trails and viewpoints
Jenny Lake, Cascade Canyon, and the Teton Crest Trail all start in or climb out of the valley pool, so an early start from a valley trailhead often means walking up out of the smoke within the first thousand feet. The Snake River Overlook and the other classic viewpoints are on the valley floor and are the first things a smoke layer takes away.
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.