The Air / Central Valley

Air quality in Visalia right now

56ModerateUS AQI · updated 10:18 PM PT

VISALIA — The air over Visalia reads 56 on the federal index tonight — moderate.

The pollutants, against the WHO guideline

Pollutant	Now	WHO 24h	× guideline
PM2.5 µg/m³	12.6	15	0.8×
PM10 µg/m³	26.9	45	0.6×
Ozone µg/m³	78	100	0.8×
NO₂ µg/m³	17.6	25	0.7×
SO₂ µg/m³	1.1	40	0.0×
CO mg/m³	0.1	4	0.0×

Source: Open-Meteo (Copernicus CAMS) · WHO 2021 global air quality guidelines · No figure on this page is written by hand.

What this air means

For most people this air changes nothing. The most sensitive — people with asthma, COPD, or heart disease — may notice it on long, hard exertion outdoors; everyone else can carry on.

The mechanism, briefly

Particles under 2.5 microns — a fortieth the width of a hair — ride air all the way to the alveoli, the one-cell-thick membrane where the lung hands oxygen to the blood. The membrane cannot tell oxygen’s friends from its enemies: within an hour of significant exposure, ultrafine particulate is circulating. That is why the numbers on this page are worth checking — dose is the only variable you control.

From the Air desk

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Nearby

Fresno · Bakersfield · Merced · San Luis Obispo · Santa Barbara · Lancaster

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