SmogRank / United States / Colorado / Aurora

Aurora, month by month

Aurora has a measured daily mean on 4 days since 3 October 2026.

Every month since 2026

2026too few days for a mean (a year needs 199)4 days measured

JanFebMarAprMayJunJulAugSepOct4 days

Each square is a month's mean PM2.5 in US AQI from Aurora's measured days, with its place on that month's world ranking under it. A month has a mean once 70% of its days are measured, the rule the monthly rankings use; under that, the square gives the days measured. Each square opens that month's ranking with Aurora marked; each year, the year's.

Good0–50

Moderate51–100

Sensitive groups101–150

Unhealthy151–200

Very unhealthy201–300

Hazardous301+

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

Months without a mean, and why

1 month

Month	Why
Oct 2026	4 of 11 days measured; a month needs 8. The others: 1 with no readings from the monitors, 4 with readings for part of the day (a day needs 18 hours).

A day counts once 18 hours of it are measured; a month needs 70% of its days.

Aurora's worst days

Day	US AQI
7 Oct 2026	366.5 µg/m³
4 Oct 2026	244.4 µg/m³
5 Oct 2026	203.6 µg/m³
3 Oct 2026	162.8 µg/m³

Daily means, the highest since 3 Oct 2026; the WHO's daily guideline is 15 µg/m³. Each date opens that day's world ranking, and each episode the bad-air spell it was part of.

Use this history

SmogRank, PM2.5 monthly and daily means, Aurora, United States, 3 Oct 2026 – 7 Oct 2026. Monitor data from Clarity, AirGradient and Love My Air Denver via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/us/aurora/history (accessed 12 Oct 2026). Contains readings from Love My Air (City and County of Denver), no reuse terms published.

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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.

Aurora now: the last 24 hours, its ranks today and the last 12 months day by day.

Updated 2026-10-12 18:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index. Some low-cost readings: Sensor.Community, ODbL (data and licence). Some readings: Uzhydromet (Uzbekistan's Hydrometeorological Service); Department of Environment, Nepal; Vietnam's government monitors; Aurassure; Umhverfisstofnun (Environment Agency of Iceland); RMCAB (Secretaría Distrital de Ambiente, Bogotá); Love My Air (City and County of Denver), no reuse terms published (why we use them).