SmogRank / United States / Hawaii / Kīhei

Kīhei, month by month

Kīhei has a measured daily mean on 1,067 days since 22 August 2023. Its worst month was February 2025, at 28 US AQI (5.0 µg/m³), 2,581st of 2,852 cities on that month's world ranking. Its cleanest was September 2024, at 13 US AQI (2.4 µg/m³). 2025 averaged 22 US AQI (3.9 µg/m³), against 18 US AQI (3.2 µg/m³) in 2024.

Every month since 2023

202622 so far263 days measured3,156th of 3,214 in the world

Jan21 daysFeb23#3,024 Mar23#3,116 Apr22#3,071 May27#2,758 Jun19#3,089 Jul20#2,980 Aug22#3,139 Sep22#3,110 Oct20#3,031

202522 for the year330 days measured2,881st of 2,926 in the world

Jan23#2,616 Feb28#2,581 Mar23#2,855 Apr25#2,863 May19#2,989 Jun19#3,051 Jul20#2,983 Aug21#3,028 Sep19#3,166 Oct20#2,888Nov15 daysDec21#3,082

202418 for the year348 days measured2,083rd of 2,097 in the world

Jan18#2,326 Feb18#2,410 Mar21#1,537 Apr21#2,292 May19#2,534 Jun18#2,471 Jul16#2,533 Aug17#1,997 Sep13#2,004 Oct16#2,002 Nov18#2,554 Dec21#2,490

2023too few days for a mean (a year needs 256)126 days measured

JanFebMarAprMayJunJulAug10 daysSep17#2,148 Oct13#2,002 Nov15#2,220 Dec14#2,225

Each square is a month's mean PM2.5 in US AQI from Kīhei'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 Kīhei marked; each year, the year's. A dashed square is the running month, so far.

Good0–50

Moderate51–100

Unhealthy for 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

3 months

Month	Why
Jan 2026	21 of 31 days measured; a month needs 22. The others: 6 with no readings from the monitor, 4 with readings for part of the day (a day needs 18 hours).
Nov 2025	15 of 30 days measured; a month needs 21. The others: 6 with no readings from the monitor, 9 with readings for part of the day (a day needs 18 hours).
Aug 2023	10 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.

Kīhei's worst months

Month	US AQI	Days measured	World rank
February 2025	285.0 µg/m³	25 of 28	2,581stof 2,852
May 2026	274.8 µg/m³	29 of 31	2,758thof 3,243
April 2025	254.5 µg/m³	30 of 30	2,863rdof 3,145
January 2025	234.2 µg/m³	23 of 31	2,616thof 2,754
March 2025	234.2 µg/m³	31 of 31	2,855thof 3,102
February 2026	234.1 µg/m³	28 of 28	3,024thof 3,180

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.

Kīhei's worst days

Day	US AQI
28 Feb 2025	6918.6 µg/m³
3 Apr 2025	6215.0 µg/m³
15 Aug 2026	6114.7 µg/m³
27 Feb 2025	6114.3 µg/m³
4 Jan 2025	5812.6 µg/m³
4 Apr 2025	5712.1 µg/m³
1 Mar 2025	5611.7 µg/m³
14 Aug 2026	5511.2 µg/m³
20 Apr 2024	498.9 µg/m³
27 Dec 2024	488.6 µg/m³

Daily means, the highest since 22 Aug 2023; 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, Kīhei, United States, 22 Aug 2023 – 12 Oct 2026. Monitor data from AirNow, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/us/kihei/history (accessed 13 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.

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

Updated 2026-10-13 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).