SmogRank / United States / California / Mission Viejo

Mission Viejo, month by month

Mission Viejo has a measured daily mean on 368 days since 3 October 2025. Its worst month was July 2026, at 55 US AQI (11.0 µg/m³), 1,114th of 2,784 cities on that month's world ranking. Its cleanest was January 2026, at 34 US AQI (6.2 µg/m³).

Every month since 2025

202649 so far284 days measured1,370th of 2,791 in the world
Jan34#2,055Feb42#2,078Mar50#1,881Apr36#2,078May52#842Jun52#688Jul55#1,114Aug54#736Sep51#763Oct48#835
2025too few days for a mean (a year needs 256)84 days measured
JanFebMarAprMayJunJulAugSepOct37#1,326Nov52#1,067Dec53#1,251
Each square is a month's mean PM2.5 in US AQI from Mission Viejo'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 Mission Viejo marked; each year, the year's. A dashed square is the running month, so far.
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

Mission Viejo's worst months

MonthUS AQIDays measuredWorld rank
July 2026 5511.0 µg/m³31 of 311,114thof 2,784
August 2026 5410.8 µg/m³31 of 31736thof 2,896
December 2025 5310.4 µg/m³31 of 311,251stof 3,006
November 2025 529.8 µg/m³24 of 301,067thof 2,715
June 2026 529.8 µg/m³30 of 30688thof 2,497
May 2026 529.7 µg/m³31 of 31842ndof 2,874

Monthly means over the days measured; finished months only. World rank: its place on that month's world ranking of every city with enough days. Each month opens that ranking.

Mission Viejo's worst days

DayUS AQI
17 May 2026 8024.5 µg/m³
14 Dec 2025 7421.6 µg/m³
2 Nov 2025 7220.6 µg/m³
22 Dec 2025 7220.5 µg/m³
15 Dec 2025 7119.8 µg/m³
22 Jan 2026 7119.7 µg/m³
13 Dec 2025 7019.1 µg/m³
21 Dec 2025 6818.3 µg/m³
1 Nov 2025 6818.0 µg/m³
18 May 2026 6818.0 µg/m³

Daily means, the highest since 3 Oct 2025; 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, Mission Viejo, United States, 3 Oct 2025 – 11 Oct 2026. Monitor data from AirNow, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/us/mission-viejo/history (accessed 12 Oct 2026).

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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.

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

Updated 2026-10-12 20:07 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).