Worst air pollution Merced, today and tomorrow
Today (15 July): Air quality in Merced is fair. PM2.5 and NO2 are fair; AQI and O3 are medium; PM10, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 9:00 AM (O3: 45.8/100).
Tomorrow (16 July 2026): Air quality in Merced is fair. NO2 decreases to medium; PM1 increases to fair; all other pollutants stay as today. Pollution peaks around 9:00 AM (O3: 44.7/100). 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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Merced's air quality reflects the San Joaquin Valley's enclosed basin position, sharing the valley's persistent pollution trap between the Sierra Nevada and the Coast Range with the additional contribution of the surrounding Merced County dairy and almond farming operations generating agricultural emissions. Winter tule fog inversions trap vehicle and agricultural emissions, while the UC Merced campus and the Castle Air Force Base legacy contribute local sources, and summer ozone from the valley's combined vehicle and agricultural emissions is the primary warm-season concern.
Today - 15 July | Pollution peaks at 09:00
AQI:
Medium
45.8/100
PM2.5 (fine particles):
Fair
24.1/100
PM10 (coarse particles):
Good
15.5/100
NO2 (nitrogen dioxide):
Fair
30.0/100
O3 (ozone):
Medium
45.8/100
SO2 (sulfur dioxide):
Good
10.6/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
2.6/100
PM1 (ultrafine particles):
Good
15.0/100
Levels show the poorest local air quality during the day
Tomorrow - 16 July | Pollution peaks at 09:00
AQI:
Medium
44.7/100
PM2.5 (fine particles):
Fair
30.6/100
PM10 (coarse particles):
Good
16.0/100
NO2 (nitrogen dioxide):
Medium
42.6/100
O3 (ozone):
Medium
44.7/100
SO2 (sulfur dioxide):
Good
10.1/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
2.2/100
PM1 (ultrafine particles):
Fair
20.3/100
Pollen forecast in Merced
View pollen forecastFrequently Asked Questions
Is air quality bad in Merced right now?
On 15 July 2026, overall air quality in Merced is fair. NO2 is the main pollutant at 30.0/100. Pollution peaks around 9:00 AM (O3: 45.8/100).
Will air quality be worse tomorrow in Merced?
On 16 July 2026, air quality conditions in Merced will be similar to today, with PM2.5 forecast at fair at 30.6/100. Pollution peaks around 9:00 AM (O3: 44.7/100).
When is air pollution at its worst in Merced?
Merced sees air quality change through the year — 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. The mountains ringing the basin can trap pollution close to the ground for days when winds are calm.
Are air quality levels in Merced 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.
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Data provided by Airmine — Last update: 16 July 2026 at 10:33 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.
For long term forecasts and maps, see the Airmine app