SmogRank / United States / California / Whittier

Whittier, month by month

Whittier has a measured daily mean on 295 days since 27 November 2025. Its worst month was December 2025, at 79 US AQI (24.3 µg/m³), 381st of 3,006 cities on that month's world ranking. Its cleanest was April 2026, at 45 US AQI (8.1 µg/m³).

Every month since 2025

202657 so far266 days measured700th of 2,793 in the world
Jan63#725Feb55#1,114Mar60#956Apr45#1,559May57#565Jun56#506Jul62#531Aug60#447Sep54#606Oct54#512
2025too few days for a mean (a year needs 256)29 days measured
JanFebMarAprMayJunJulAugSepOctNov4 daysDec79#381
Each square is a month's mean PM2.5 in US AQI from Whittier'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 Whittier 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

Months without a mean, and why

1 month
MonthWhy
Nov 20254 of 30 days measured; a month needs 21.

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

Whittier's worst months

MonthUS AQIDays measuredWorld rankEpisode
December 2025 7924.3 µg/m³25 of 31381stof 3,006Western United States and Mexico, December 2025
January 2026 6315.6 µg/m³26 of 31725thof 2,617California, United States, 21 to 22 January 2026
July 2026 6214.8 µg/m³31 of 31531stof 2,784–
March 2026 6013.9 µg/m³31 of 31956thof 2,971–
August 2026 6013.7 µg/m³29 of 31447thof 2,896–
May 2026 5712.2 µg/m³30 of 31565thof 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.

Whittier's worst days

DayUS AQIEpisode
17 Dec 2025 14452.8 µg/m³Western United States and Mexico, December 2025
21 Jan 2026 13549.4 µg/m³California, United States, 21 to 22 January 2026
18 Dec 2025 12846.5 µg/m³Western United States and Mexico, December 2025
22 Jan 2026 12746.2 µg/m³California, United States, 21 to 22 January 2026
22 Dec 2025 12645.6 µg/m³Western United States and Mexico, December 2025
13 Dec 2025 12344.6 µg/m³Western United States and Mexico, December 2025
4 Jul 2026 11943.0 µg/m³–
16 Dec 2025 11139.4 µg/m³Western United States and Mexico, December 2025
14 Dec 2025 10637.7 µg/m³Western United States and Mexico, December 2025
30 Nov 2025 9834.5 µg/m³–

Daily means, the highest since 27 Nov 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, Whittier, United States, 27 Nov 2025 – 11 Oct 2026. Monitor data from AirNow, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/us/whittier/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.

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

Updated 2026-10-12 22:07 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).