Air Quality in Nampa, Idaho — Live

Live readings from PurpleAir sensors across Nampa — with free alerts when winter inversions or harvest smoke move in.

Live Nampa AQI from nearby PurpleAir sensors loads when this page opens in a browser, along with a live sensor map covering Nampa and Caldwell, Meridian, Middleton, Kuna.

Nampa's air is good most of the year — the Treasure Valley's pollution problems come less from freeways than from the farm country and winter weather that surround it. Two stretches of the year are different: cold winter nights, when the valley's own shape traps exhaust and wood smoke close to the ground, and harvest season, when Canyon County's fields get cleared with permitted, real crop-residue burning that fills the air with smoke you can actually see and smell.

Canairy watches the sensors around your home, your kids' school, and everywhere else you care about, and tells you in plain English when the air changes enough to matter.

The Treasure Valley traps its own air in winter

Nampa sits at about 2,474 feet elevation in the Treasure Valley, roughly 20 miles west of Boise, in a basin framed by the Boise foothills to the north and the high desert of the Owyhee uplands to the south. On cold, still nights — common in an Idaho winter — a layer of warmer air settles over the valley like a lid, trapping the cooler air, and everything the valley's cars, wood stoves, and farm equipment put into the air stays low instead of clearing out.

That mechanism was serious enough for decades that neighboring Ada County (Boise) still carries federal 'maintenance area' status from the EPA: a carbon monoxide nonattainment designation redesignated to maintenance in 2002, and a PM-10 particulate designation redesignated to maintenance in 2003 — both textbook results of winter inversions holding vehicle exhaust and fine dust close to the ground. Canyon County, where Nampa sits, shares the same valley floor and the same trapped air; an inversion doesn't stop at a county line.

Harvest season means real, permitted smoke over the fields

Canyon County is one of Idaho's most productive farm counties, and once crops like mint, onions, sugar beets, and corn are harvested, growers across the valley clear the stubble with crop-residue burning — a real practice regulated and tracked through Idaho DEQ's crop residue and spot-and-bale burn permit program, with rules meant to keep smoke away from schools, hospitals, and other sensitive sites nearby.

This isn't a hypothetical: DEQ actively manages burn days around the valley's weather, and outdoor burning across Canyon County (along with Ada and ten other Idaho counties) has been prohibited outright during active air quality advisories. In a typical year the heaviest agricultural burning runs from late summer into fall, and on top of it, haze can drift in from wildfires burning elsewhere in the Northwest.

What actually helps on a bad-air day in Nampa

On a winter inversion morning, checking the forecast matters more than checking the sky — the coldest, stillest mornings are often the worst even under clear blue skies, because the pollution is trapped low and fine rather than visible as haze. Closing up the house before the air turns and running a purifier indoors beats waiting until you can smell smoke or exhaust, since the small particles that build up during an inversion do their damage long before you'd notice anything by eye or nose.

Canairy reads the PurpleAir sensors placed around Nampa and Canyon County instead of leaning on one distant monitor, because a single valley-wide number hides real differences — the air near a field mid-burn can be very different from the air downtown at the same hour. Set a threshold once, and Canairy tells you when it's crossed, in either direction.

Nampa air quality FAQ

What is the air quality in Nampa right now?

This page shows the current AQI for Nampa, calculated from PurpleAir sensors across the city and updated continuously. The map below shows every live sensor, so you can check the reading closest to your own neighborhood.

Why does Nampa's air get worse in winter?

Nampa sits in the Treasure Valley, a basin ringed by higher ground that traps cold air close to the surface on calm winter nights. That trapped layer holds vehicle exhaust, wood-stove smoke, and fine dust near the ground instead of letting it disperse — the same inversion pattern that gave neighboring Ada County a long federal history of carbon monoxide and PM-10 maintenance-area status.

Why does it smell like smoke around Nampa during harvest season?

Canyon County farmers burn crop residue from fields after harvest, a permitted and DEQ-regulated practice used to clear stubble from crops like mint, onions, and sugar beets. Burn days are approved around the valley's weather and restricted near schools and hospitals, but on approved days the smoke is real and can affect neighborhoods well outside the fields themselves.

What AQI level is unhealthy?

Under the US EPA scale, AQI 0-50 is Good and 51-100 is Moderate. From 101 the air is Unhealthy for Sensitive Groups - kids, older adults, and people with asthma or heart conditions - and above 150 it's Unhealthy for everyone. Canairy translates these numbers into a plain-English verdict, like whether to close the windows or move a workout indoors.

Where does Canairy's Nampa data come from?

Readings come from PurpleAir's network of laser particle sensors across Nampa and surrounding towns, cross-referenced with government monitors and the Google Air Quality API. You can see every sensor behind your numbers on the live map - there's no black box.

Is Canairy free?

Yes. The Canairy app is free to download and includes live air quality for all your saved places, plain-English verdicts, and free push alerts when the air crosses your threshold. A paid plan adds extras like SMS text alerts.

Get Canairy free on Google Play.