Steamboat Springs, CO Air Quality

EPA monitor data through 2025 · Updated September 02, 2026 · Methods

In 2025, Steamboat Springs, CO recorded 0 days above an Air Quality Index of 100, the level at which EPA begins warning sensitive groups, out of 365 days with monitoring data. The rest of the year was 342 Good days and 23 Moderate days. Under the AQI rules that applied before 2013, the same air would have scored 0 days.

Unhealthy days, 2025
0
AQI above 100
Same air, pre-2013 rules
0
for comparison with older reports
Good-air days
342
AQI 50 or below
Days monitored
365
full year

Unhealthy days by year, scored two ways

EPA changed what an AQI of 100 means in 2013 and again in 2015, so a count published before those changes is not comparable to one published after. Each panel below applies a single fixed rulebook to every year, so each is internally consistent. Why this matters.

Scored by today's rules

Steamboat Springs, CO: days above AQI 100 by year, current rules 0 1 2000 2005 2010 2015 2020 2025 2000: 0 days 2001: 0 days 2002: 0 days 2003: 0 days 2004: 0 days 2005: 0 days 2006: 0 days 2007: 0 days 2008: 0 days (incomplete monitoring) 2009: 0 days 2010: 0 days 2011: 0 days 2012: 0 days 2013: 0 days 2014: 0 days 2015: 0 days 2016: 0 days 2017: 0 days 2018: 0 days 2019: 1 days 2020: 0 days 2021: 0 days 2022: 0 days 2023: 0 days 2024: 0 days 2025: 0 days

Scored by the pre-2013 rules

Steamboat Springs, CO: days above AQI 100 by year, pre-2013 rules 0 1 2000 2005 2010 2015 2020 2025 2000: 0 days 2001: 0 days 2002: 0 days 2003: 0 days 2004: 0 days 2005: 0 days 2006: 0 days 2007: 0 days 2008: 0 days (incomplete monitoring) 2009: 0 days 2010: 0 days 2011: 0 days 2012: 0 days 2013: 0 days 2014: 0 days 2015: 0 days 2016: 0 days 2017: 0 days 2018: 0 days 2019: 1 days 2020: 0 days 2021: 0 days 2022: 0 days 2023: 0 days 2024: 0 days 2025: 0 days
Faded columns mark years with fewer than 300 monitored days, where the count is not comparable.

What 2025 looked like

Air quality categoryDaysShare of days with an AQI
Good34294%
Moderate236%
Unhealthy for sensitive groups00%
Unhealthy or worse00%

Median AQI 22 · 90th-percentile AQI 42 · worst day 87. Scored under current rules, out of 365 days with an AQI.

Statewide context

Steamboat Springs, CO sits in Colorado.

Days in each air quality category, by year

How many days fell in each AQI category, for every year with an AQI on record. Categories are scored under EPA's current breakpoints. A year with fewer than 300 days is marked, because a short year lowers every count for reasons that have nothing to do with the air.

YearGoodModerate Unhealthy for sensitive groupsUnhealthy or worse Days with an AQI
2000 306310 0337
2001 321300 0351
2002 315330 0348
2003 323280 0351
2004 304300 0334
2005 310190 0329
2006 331210 0352
2007 340170 0357
2008 (partial) 276220 0298
2009 331190 0350
2010 331200 0351
2011 331120 0343
2012 34670 0353
2013 336130 0349
2014 334120 0346
2015 35770 0364
2016 34390 0352
2017 33390 0342
2018 35410 0355
2019 35321 0356
2020 35350 0358
2021 34770 0354
2022 35600 0356
2023 34850 0353
2024 36410 0365
2025 342230 0365

Good is AQI 0–50, Moderate 51–100, Unhealthy for sensitive groups 101–150. “Unhealthy or worse” combines the Unhealthy, Very Unhealthy and Hazardous categories, which are shown together because most areas record too few of each to report separately. The four columns sum to the last one by construction. These counts exclude sulphur dioxide, following EPA, which drops SO₂ from county and metro summaries because it is too localized to describe a whole area.

The full series

The same years scored two ways, with the pollutant that drove the days above 100. EPA's files record which pollutant set each day's AQI; they do not attribute days to wildfire smoke, so no column here claims to.

YearUnhealthy days, current rulesOf which ozone Of which fine particlesPre-2013 rulesDays monitored
20000 0 0 0337
20010 0 0 0351
20020 0 0 0348
20030 0 0 0351
20040 0 0 0334
20050 0 0 0329
20060 0 0 0352
20070 0 0 0357
20080 0 0 0298
20090 0 0 0350
20100 0 0 0351
20110 0 0 0343
20120 0 0 0353
20130 0 0 0349
20140 0 0 0346
20150 0 0 0364
20160 0 0 0352
20170 0 0 0342
20180 0 0 0355
20191 0 0 1356
20200 0 0 0358
20210 0 0 0354
20220 0 0 0356
20230 0 0 0353
20240 0 0 0365
20250 0 0 0365

Sources