The default web address (URL) for the AirNow map is https://gispub.epa.gov/airnow/index.html.

(Your map may look slightly different depending on many factors, like screen width, resolution, browser, etc.)

This default map:

• displays the lower 48 states
• displays the Ozone and PM contour overlay
• does not show the green areas of contours (making the map more visible)
• does not display monitors

Much of the map—including what tab you start at—can be changed by manipulating the URL variables. Read below for a quick explanation of how to change these variables so that you can link to a custom version of this map.

This document has basically three sections:

• Keeping It Simple: Basic instructions for setting up the map and copying the URL it generates. The vast majority of folks should be fine using this, only this, and skipping all the other sections.
• Building A Custom Map: Some detailed instructions for assembling URLs on your own.
• Technical Reference: Reference for all the variables and their accepted values.