SmogRank / United States / Colorado / Alamosa

Alamosa, month by month

Alamosa has a measured daily mean on 959 days since 22 January 2024. Its worst month was August 2025, at 47 US AQI (8.5 µg/m³), 1,639th of 2,901 cities on that month's world ranking. Its cleanest was February 2025, at 18 US AQI (3.2 µg/m³). 2025 averaged 28 US AQI (5.1 µg/m³), against 28 US AQI (5.1 µg/m³) in 2024.

Every month since 2024

202630 so far270 days measured2,589th of 2,791 in the world
Jan34#2,055Feb29#2,557Mar31#2,616Apr19#2,822May24#2,540Jun32#1,981Jul40#2,098Aug41#1,948Sep19#2,867Oct23#2,457
202528 for the year354 days measured2,515th of 2,681 in the world
Jan31#2,093Feb18#2,594Mar22#2,666Apr23#2,737May21#2,645Jun26#2,329Jul40#1,952Aug47#1,639Sep21#2,973Oct21#2,448Nov36#2,076Dec34#2,428
202428 for the year335 days measured1,938th of 2,097 in the world
Jan9 daysFeb21#2,352Mar21#1,537Apr19#2,336May25#2,365Jun25#2,312Jul38#1,765Aug21#1,972Sep28#1,766Oct35#1,378Nov31#2,171Dec43#1,431
Each square is a month's mean PM2.5 in US AQI from Alamosa'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 Alamosa 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
Jan 20249 of 31 days measured; a month needs 22. The others: 1 with readings for part of the day (a day needs 18 hours).

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

Alamosa's worst months

MonthUS AQIDays measuredWorld rank
August 2025 478.5 µg/m³31 of 311,639thof 2,901
December 2024 437.8 µg/m³29 of 311,431stof 2,616
August 2026 417.3 µg/m³31 of 311,948thof 2,896
July 2025 407.2 µg/m³30 of 311,952ndof 2,889
July 2026 407.2 µg/m³26 of 312,098thof 2,784
July 2024 386.8 µg/m³31 of 311,765thof 2,566

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.

Alamosa's worst days

DayUS AQI
15 Mar 2026 9532.5 µg/m³
4 Jul 2026 7522.1 µg/m³
4 Aug 2026 7421.4 µg/m³
24 Jul 2024 7321.1 µg/m³
4 Aug 2025 7320.7 µg/m³
16 Jul 2025 7220.4 µg/m³
23 Jul 2024 7120.1 µg/m³
11 Jul 2025 7119.6 µg/m³
6 Aug 2026 6717.6 µg/m³
14 Aug 2025 6617.2 µg/m³

Daily means, the highest since 22 Jan 2024; 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, Alamosa, United States, 22 Jan 2024 – 11 Oct 2026. Monitor data from AirNow, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/us/alamosa/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.

Alamosa 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).