Delano, month by month

Delano has a measured daily mean on 348 days since 28 October 2025. Its worst month was January 2026, at 95 US AQI (32.6 µg/m³), 148th of 2,617 cities on that month's world ranking. Its cleanest was July 2026, at 22 US AQI (4.0 µg/m³).

Every month since 2025

202657 so far283 days measured

Jan95#148 Feb76#465 Mar70#629 Apr33#2,210 May40#1,565 Jun22#2,300 Jul22#2,701 Aug42#1,859 Sep37 Oct52so far

2025too few days for a mean (a year needs 256)65 days measured

JanFebMarAprMayJunJulAugSepOct4 daysNov79#317 Dec82#352

Each square is a month's mean PM2.5 in US AQI from Delano'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 Delano 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

Month	Why
Oct 2025	4 of 31 days measured; a month needs 22.

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

Delano's worst months

Month	US AQI	Days measured	World rank
January 2026	9532.6 µg/m³	31 of 31	148thof 2,617
December 2025	8226.0 µg/m³	31 of 31	352ndof 3,006
November 2025	7923.9 µg/m³	30 of 30	317thof 2,715
February 2026	7622.4 µg/m³	28 of 28	465thof 2,866
March 2026	7019.3 µg/m³	31 of 31	629thof 2,971
August 2026	427.5 µg/m³	31 of 31	1,859thof 2,896

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.

Delano's worst days

Day	US AQI
15 Jan 2026	15662.1 µg/m³
14 Jan 2026	15662.0 µg/m³
16 Jan 2026	15359.0 µg/m³
1 Feb 2026	15156.2 µg/m³
2 Feb 2026	14854.6 µg/m³
31 Jan 2026	14754.1 µg/m³
5 Feb 2026	13750.2 µg/m³
4 Feb 2026	13649.8 µg/m³
13 Jan 2026	13649.6 µg/m³
30 Jan 2026	13549.2 µg/m³

Daily means, the highest since 28 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, Delano, United States, 28 Oct 2025 – 11 Oct 2026. Monitor data from national networks via OpenAQ and the publishers listed at smogrank.com/sources. smogrank.com/us/delano/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.

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

Updated 2026-10-12 19:07 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).