Find your place using search or the text directory and open a station. Confirm the station name and location, then check the provider and source link. A search match does not guarantee a current observation.
Read observation time before retrieval time: a newly retrieved record may describe older conditions. Check freshness, the AQI standard and any pollutant's unit and averaging period. AQI is an index, not a concentration; a concentration in µg/m³ or ppb must not be treated as an AQI score.
Open recorded history and its table to see which values actually exist. For comparisons, use Trends to select up to five stations and one pollutant and period, checking matching units and averaging windows. Missing values remain unknown. A nearby station does not measure personal exposure.
When reporting a problem, include the station, observation time, original source URL and the correction you believe the evidence supports. Do not send private health or identity information.