Grand Canyon 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 Canyon National Park.
The South Rim sits near 7,000 feet and the Colorado River is about 2,400 feet, so the terrain here is a hole rather than a peak. That inverts the usual mountain logic: cold air and smoke drain downward into the canyon overnight and pool below the rim, so the view from the top can be obliterated while the rim itself has clean air.
Where the smoke comes from
The Kaibab Plateau is the closest source and produces two different kinds of smoke. Wildfires on the North Rim and along the plateau burn mainly in May and June, and the park and the Kaibab National Forest run prescribed burns on a regular schedule, which put predictable, planned smoke into the canyon on calm mornings with no wildfire in the region. California and Great Basin transport adds a high layer later in the summer.
How long it lasts
Mid-morning heating lifts the pooled layer out of the canyon, usually a few hours after sunrise. Visitors who come for sunrise at Mather or Hopi Point are arriving at the worst hour of the day for visibility, and the same viewpoint is often clear by ten. Multi-day episodes need a wind shift.
Past smoke events
The 2020 Mangum Fire burned more than 70,000 acres on the North Rim and closed access there for the season. Prescribed-burn smoke affects rim visibility most spring seasons and is announced by the park in advance.
Trails and viewpoints
Bright Angel and South Kaibab both descend into the layer that pools overnight, so a hiker starting at dawn is walking down into the smoke rather than out of it. Rim Trail viewpoints and the North Rim at 8,300 feet stay above the pooled layer even when the canyon below is full.
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.