SmogRank / United States / Arizona / Prescott

Prescott, month by month

Prescott has a measured daily mean on 264 days since 8 April 2025. Its worst month was April 2025, at 12 US AQI (2.2 µg/m³), 2,945th of 2,951 cities on that month's world ranking.

Every month since 2025

2026too few days for a mean (a year needs 199)130 days measured
Jan17 daysFeb17 daysMar10 daysApr11 daysMay15 daysJun6 daysJul15 daysAug16 daysSep16 daysOct7 days
2025too few days for a mean (a year needs 256)134 days measured
JanFebMarApr12#2,945May21 daysJun10 daysJul21 daysAug17 daysSep12 daysOct8 daysNov10 daysDec12 days
Each square is a month's mean PM2.5 in US AQI from Prescott'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 Prescott 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

18 months
MonthWhy
Oct 20267 of 11 days measured; a month needs 8. The others: 4 with readings for part of the day (a day needs 18 hours).
Sep 202616 of 30 days measured; a month needs 21. The others: 14 with readings for part of the day (a day needs 18 hours).
Aug 202616 of 31 days measured; a month needs 22. The others: 15 with under 18 hours of readings or readings that failed our checks.
Jul 202615 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks.
Jun 20266 of 30 days measured; a month needs 21. The others: 24 with under 18 hours of readings or readings that failed our checks.
May 202615 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks.
Apr 202611 of 30 days measured; a month needs 21. The others: 19 with under 18 hours of readings or readings that failed our checks.
Mar 202610 of 31 days measured; a month needs 22. The others: 21 with under 18 hours of readings or readings that failed our checks.
Feb 202617 of 28 days measured; a month needs 20. The others: 11 with under 18 hours of readings or readings that failed our checks.
Jan 202617 of 31 days measured; a month needs 22. The others: 14 with under 18 hours of readings or readings that failed our checks.
Dec 202512 of 31 days measured; a month needs 22. The others: 19 with under 18 hours of readings or readings that failed our checks.
Nov 202510 of 30 days measured; a month needs 21. The others: 20 with under 18 hours of readings or readings that failed our checks.
Oct 20258 of 31 days measured; a month needs 22. The others: 23 with under 18 hours of readings or readings that failed our checks.
Sep 202512 of 30 days measured; a month needs 21. The others: 18 with under 18 hours of readings or readings that failed our checks.
Aug 202517 of 31 days measured; a month needs 22. The others: 14 with under 18 hours of readings or readings that failed our checks.
Jul 202521 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks.
Jun 202510 of 30 days measured; a month needs 21. The others: 20 with under 18 hours of readings or readings that failed our checks.
May 202521 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks.

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

Prescott's worst months

MonthUS AQIDays measuredWorld rank
April 2025 122.2 µg/m³23 of 302,945thof 2,951

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.

Prescott's worst days

DayUS AQI
13 Jul 2026 8427.0 µg/m³
8 Oct 2026 6416.3 µg/m³
9 Aug 2026 6315.7 µg/m³
1 Jul 2025 6315.6 µg/m³
4 Aug 2026 6215.1 µg/m³
9 Oct 2026 6215.1 µg/m³
14 Jun 2025 6215.0 µg/m³
18 May 2026 6214.8 µg/m³
17 Jul 2025 6114.6 µg/m³
11 Aug 2025 6114.6 µg/m³

Daily means, the highest since 8 Apr 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, Prescott, United States, 8 Apr 2025 – 9 Oct 2026. Monitor data from AirNow, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/us/prescott/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.

Prescott 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).