Phoenix 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 Phoenix.
Phoenix sits at about 1,100 feet in the Salt River Valley, a broad Sonoran desert basin ringed by low ranges. Extreme daytime heating produces a very deep mixed layer, which is why the city disperses smoke better than its bowl shape suggests. The trapping that does happen is nocturnal, when drainage winds bring cooler air down the Verde and Salt river corridors from the high country.
Where the smoke comes from
Arizona's fire calendar peaks in May and June, before the monsoon arrives, which is months earlier than the Northwest. The ponderosa belt along the Mogollon Rim is the main source, roughly 100 miles northeast, and its smoke reaches Phoenix overnight on drainage flow. Prescribed burns on the Coconino and Tonto forests add smoke on calm spring mornings with no wildfire anywhere. A second, higher layer arrives in late summer from Pacific Northwest and California fires.
How long it lasts
Daytime heating usually does it. Once the surface warms and the mixed layer deepens, drainage smoke that pooled overnight is diluted through a very deep column and surface readings drop sharply. The pattern is a morning peak and an afternoon minimum, the reverse of Denver.
Past smoke events
The 2020 Bush Fire and the 2021 Telegraph Fire both put significant smoke over the metro area, and Rim-country fires deliver lighter overnight episodes most spring seasons.
Running, riding, and trailheads
South Mountain, Camelback, and Piestewa Peak are all early-morning destinations because of the heat, which is unfortunately the same window when drainage smoke is densest. During a Rim fire, the usual advice to start before sunrise is worth checking against the hourly forecast rather than following by habit.
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.