Worst air pollution Carlsbad, today and tomorrow
Today (20 September): Air quality in Carlsbad is moderate. AQI and PM10 are moderate; PM2.5 and NO2 are fair; O3, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 10:00 AM (PM10: 46.2/100).
Tomorrow (21 September 2026): Air quality in Carlsbad is moderate. NO2 decreases to good; all other pollutants stay as today. Pollution peaks around 2:00 AM (PM10: 40.8/100). Airmine updates local air quality forecasts four times daily.
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Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team
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Carlsbad's air quality benefits from direct Pacific Ocean coastal exposure on the San Diego County coast, with consistent onshore sea breezes providing reliable maritime ventilation. Vehicle emissions from I-5 and the surrounding biotechnology campus corridor are the primary local sources, while the coastal position provides significantly better conditions than the inland San Diego County valleys throughout most of the year.
Today - 20 September | Pollution peaks at 10:00
AQI:
Moderate
46.2/100
PM2.5 (fine particles):
Fair
33.0/100
PM10 (coarse particles):
Moderate
46.2/100
NO2 (nitrogen dioxide):
Fair
20.4/100
O3 (ozone):
Good
14.1/100
SO2 (sulfur dioxide):
Good
0.3/100
CO (carbon monoxide):
Good
0.4/100
HCHO (formaldehyde):
Good
1.3/100
PM1 (ultrafine particles):
Good
8.9/100
Levels show the poorest local air quality during the day
Tomorrow - 21 September | Pollution peaks at 02:00
AQI:
Moderate
40.8/100
PM2.5 (fine particles):
Fair
28.4/100
PM10 (coarse particles):
Moderate
40.8/100
NO2 (nitrogen dioxide):
Good
13.5/100
O3 (ozone):
Good
14.8/100
SO2 (sulfur dioxide):
Good
0.4/100
CO (carbon monoxide):
Good
0.4/100
HCHO (formaldehyde):
Good
1.2/100
PM1 (ultrafine particles):
Good
10.2/100
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Frequently Asked Questions
Is air quality bad in Carlsbad right now?
On 20 September 2026, overall air quality in Carlsbad is moderate. AQI is the main air quality indicator at 46.2/100. Pollution peaks around 10:00 AM (PM10: 46.2/100).
Will air quality be worse tomorrow in Carlsbad?
On 21 September 2026, air quality conditions in Carlsbad will be similar to today, with AQI forecast at moderate at 40.8/100. Pollution peaks around 2:00 AM (PM10: 40.8/100).
When is air pollution at its worst in Carlsbad?
Air quality across Carlsbad rises and falls with the seasons. In short, winter rains provide the only real relief from an otherwise persistent haze, whereas summer and early autumn bring the highest ozone levels, and wildfire smoke can spike particulate readings sharply from August through October. Coastal breezes offer some relief compared to inland valley locations that see heavier smog buildup.
Are air quality levels in Carlsbad based on measurements or forecasts?
It is forecasts derived by downscaling forecasts provided by EU’s Copernicus Atmosphere Monitoring Service (CAMS) by taking into account local conditions such as traffic patterns. CAMS bases its forecast on satellite measurements of particles and chemical compounds in the atmosphere. Airmine’s services were developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team.
Why doesn’t the forecast always reflect wildfire impacts?
Airmine’s forecast uses CAMS (Copernicus Atmosphere Monitoring Service) as its background atmospheric model. While CAMS includes wildfire emissions, these are derived from satellite observations and are not available in real time. During rapidly evolving wildfire events, there may therefore be a delay before increased emissions are incorporated into the model. As a result, the forecast may temporarily underestimate PM₂.₅ and other pollutants associated with wildfire smoke.
During rapidly evolving wildfire events, CAMS may lag by approximately 1–2 days before increased wildfire emissions are fully represented, which can lead to temporary underestimation of PM₂.₅ concentrations in Airmine’s forecast.
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Data provided by Airmine — Last update: 20 September 2026 at 14:33 CEST (Data is updated four times daily.)
This forecast is produced independently using Airmine's own atmospheric data and models.
Unless explicitly made clear, the content on this site has not been paid for by external organisations and is Airmine's sole responsibility.
Disclaimer: Forecasts are provided for informational purposes only and should not be relied upon as medical advice. Actual pollen and air quality conditions may vary from the forecast. If you have allergies, asthma, or another medical condition, consult a healthcare professional. Please see our Terms of Service for important information about limitations of liability.
Some text on this page may be generated or summarised using artificial intelligence (AI). Wherever possible, AI-generated content is enriched with Airmine's proprietary data to improve its accuracy and relevance. However, AI-generated content may still contain errors, omissions, or inaccuracies.
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