Procedure

1. Navigate to the web page with the GUI.
   https://aqs.epa.gov/api
   You should see a page like this

   
2. Enter the query parameters using the drop-downs or typing.

   Field	Instructions	Required?
   User Name	Your user name	Required
   Password	Your password
   Query Type	Select rawData to run an interactive (synchronous) query where you will wait for the results to be returned to your browser. Select rawDataNotify to submit a query (asynchronous) that will send you an email when complete. (The request ID for process tracking is returned immediately). Note, both queries have limits on the amount of data that can be returned, rawDataNotify has larger limits. Also, rawDataNotify will display the URL that was used to build the query, which you can edit and use again, bypassing the GUI.	Required
   Output Format	The format of the file returned by the query. The possible values are DMCSV, AQCSV, and AQS (follow links for descriptions)	Optional. Will default to DMCSV if not provided.
   Parameter Class	The classification (group) of parameters to select (e.g., Criteria, HAP, meteorological). Note, selecting an entry here will return all members of the class. It will also shorten the list below (parameter code) to just those in the class for easier selection.	One of these must be selected.
   Parameter Code	The AQS parameter code of the measurements you would like.
   Begin Date	The beginning date of the measurements you would like.	Required
   End Date	The ending date of the measurements you would like.	Required
   Min Latitude Max Latitude Min Longitude Max Longitude	The bounding box of the area you would like data from. Use decimal values, west and south are negative.	A geography selection is required. It can be: bounding box, state, state + county, state + county + site, cbsa, or csa
   State Code	The FIPS state code of the measurements you would like. Selecting a state will enable you to select a county within the state in the next box.
   County Code	The FIPS county code of the measurements you would like. Selecting a county will enable you to select a site within the county in the next box.
   Site	The unique site of the measurements you would like.
   CBSA	The core based statistical area of the measurements you would like.
   CSA	The consolidated statistical area of the measurements you would like.
   Duration	The sample duration (e.g., hourly or daily) of the measurements you would like. Note, this query by default returns samples and sub-daily averages, so if you only want hourly samples, select 1-Hour.	Optional, returns all sample durations and sub-daily averages by default.
   FRM Only	Check if you would like only federal reference method (FRM) and federal equivalent method (FEM) data.	Optional

3. Click the submit button.