San Juan, New Mexico Air Quality Today
AirHistory tracks long-run EPA monitoring rather than live readings, so for the live number check AirNow.gov below. As a baseline, San Juan, New Mexico's most recent EPA year (2023) posted a median AQI of 46 (Good) against a 5-year median of 46 and an overall Grade of C. The dominant pollutant is Ground-Level Ozone, which tells you which days are most likely to spike.
Check Today's Live AQI in San Juan, New Mexico
AirHistory is built on 10 years of EPA Air Quality System records, so it shows you what air quality in San Juan, New Mexico typically looks like — not the live reading for this exact hour. For today's real-time AQI, check AirNow.gov (the EPA's official live index) or the AirNow Fire and Smoke Map during wildfire season.
That said, the history is the best predictor of a normal day. In 2023, San Juan, New Mexico posted a median AQI of 46 (Good), with 249 "Good" days and 4 days that crossed into "Unhealthy for Sensitive Groups" or worse. The dominant pollutant, Ground-Level Ozone, is the one most likely to push today's number up — Ground-level ozone forms when sunlight reacts with vehicle exhaust and industrial emissions. It is worst on hot, sunny, stagnant summer days. Ozone irritates the lungs, triggers asthma attacks, and reduces lung function — even healthy adults can feel chest tightness and shortness of breath after exercising in elevated ozone.
San Juan, New Mexico Air Quality Snapshot
| Air Quality Grade | C59/100 |
| 5-Year Median AQI | 46 (Good) |
| Most Recent Median AQI (2023) | 46 (Good) |
| Dominant Pollutant | Ground-Level Ozone |
| 10-Year Trend | Stable (+0.19 AQI/yr) |
| Unhealthy Days (last 5 yr) | 28 |
| National Rank (cleanest = #1) | #822 of 1,020 (81th most polluted percentile) |
| New Mexico Rank | #13 of 16 |
What Does the C Grade Mean?
San Juan, New Mexico earns a C — air quality is fair, but not great. With a 5-year median AQI of 46, the city sees a meaningful number of "Moderate" days each year, when the EPA flags air as a concern for unusually sensitive people.
San Juan, New Mexico's 5-year median AQI of 46 is 5 points above the national average of 41 — meaningfully more polluted than the typical U.S. metro tracked here. Within New Mexico, San Juan, New Mexico runs more polluted than the state average of 34 — local sources or geography are concentrating pollution above the state's typical reading.
For context within New Mexico: Luna, New Mexico currently holds the state's cleanest grade (A, AQI 17), while Bernalillo, New Mexico sits at the bottom (D, AQI 59).
What's in San Juan, New Mexico's Air?
The dominant pollutant in San Juan, New Mexico is Ground-Level Ozone. Ground-level ozone forms when sunlight reacts with vehicle exhaust and industrial emissions. It is worst on hot, sunny, stagnant summer days. Ozone irritates the lungs, triggers asthma attacks, and reduces lung function — even healthy adults can feel chest tightness and shortness of breath after exercising in elevated ozone.
Days by Dominant Pollutant (2023)
| Pollutant | Days as Dominant | Share of Year |
|---|---|---|
| Ground-Level Ozone | 362 | 99% |
| Coarse Particulate Matter (PM10) | 2 | 1% |
| Nitrogen Dioxide | 1 | 0% |
Is the Air Getting Better or Worse?
Air quality in San Juan, New Mexico has held roughly steady over the past decade, with year-to-year shifts in median AQI of less than half a point. That stability makes the city's long-run grade a reliable signal of what residents can expect day-to-day.
In 2014, San Juan, New Mexico posted a median AQI of 44. By 2023 that figure was 46 — a rise of 2 AQI points dirtier across 10 years of EPA records.
Year-by-Year AQI in San Juan, New Mexico
| Year | Median AQI | Good Days | Unhealthy Days | Dominant Pollutant |
|---|---|---|---|---|
| 2014 | 44 | 272 | 0 | Ozone |
| 2015 | 44 | 263 | 2 | Ozone |
| 2016 | 44 | 273 | 2 | Ozone |
| 2017 | 47 | 230 | 6 | Ozone |
| 2018 | 47 | 213 | 16 | Ozone |
| 2019 | 49 | 208 | 0 | Ozone |
| 2020 | 45 | 265 | 5 | Ozone |
| 2021 | 46 | 237 | 8 | Ozone |
| 2022 | 45 | 238 | 11 | Ozone |
| 2023 | 46 | 249 | 4 | Ozone |
Health Context for San Juan, New Mexico
Across the past five years, this area has logged 28 days where AQI rose into the "Unhealthy for Sensitive Groups" range or worse — about 6 days per year. That is roughly typical for a U.S. metro, with most caution days clustered in summer (ozone) or wildfire season.
Healthy adults can continue normal outdoor activity in most weather, but should pay attention to AQI alerts during the worst pollution windows. People with asthma, heart disease, or pregnancy should reduce prolonged or intense outdoor exertion on flagged days, and consider running an indoor HEPA air cleaner during peak season. Because ozone peaks in the afternoon on hot sunny days, plan outdoor exercise for early morning or after sunset on bad-air days.
How This Grade Is Calculated
The AirHistory Air Quality Grade combines four signals: the 5-year median AQI (40% of the score), the 10-year trend direction (30%), the count of unhealthy days per year (20%), and the dominant pollutant type (10%). All four come directly from the EPA Air Quality System (AQS), which aggregates readings from federally certified monitors. Read the full methodology.
More about San Juan, New Mexico
San Juan, New Mexico has an Air Quality Grade of C (fair) with a 5-year median AQI of 46. The dominant pollutant is Ground-Level Ozone, and air quality has been stable over the past decade.
The data source behind this answer is the EPA Air Quality System (AQS). Every figure on the page traces back to that source; the methodology page describes the inputs and the refresh cadence in full detail.
For readers turning this answer into action: cross-reference against the underlying the EPA Air Quality System (AQS) record before acting on time-sensitive decisions. The site renders the data as it was published; subsequent revisions can shift the picture, and the live federal data is always the authoritative current reference.
Source: EPA Outdoor Air Quality Data, 2026.