Air Quality in San Marcos, United States
Drizzle
24.4°C · 82.1% humidity
24.4°
Feels 24.4°
15
Good
Air quality is satisfactory. Enjoy outdoor activities.
1 station
Nearby Monitoring Stations
San Marcos's air quality — share it
AQI Forecast
25
4pm
25
25
15
7pm
18
20
23
10pm
24
25
26
1am
26
26
25
4am
25
25
25
7am
25
25
25
10am
25
25
25
1pm
25
25
Air Quality Index Trend
47h · 1 stnSan Marcos's air quality is primarily affected by vehicle emissions and industrial activity. Seasonal wildfire smoke and weather patterns can cause periodic air quality deterioration.
82.1%
Humidity
84.7 km/h
Wind SE
1009.2 hPa
Pressure
1.4
UV Low
GoodModerateUSGUnhealthyVery UnhealthyHazardous
Which pollutant is driving the AQI?
PM2.5▲
3.6 µg/m³
PM10
13.7 µg/m³
050100150200300500
What is the weather forecast for San Marcos?
Temperature & Precipitation
PM2.5 Trend
47h · 1 stationPM2.53.6 µg/m³
✓ WHO
Good
PM1013.7 µg/m³
Good
UV INDEX1.4
Low
Station readings (1 station within 25 km)
3.6
Median
3.6
Average
3.6
Low
3.6
High
PM2.5 µg/m³ · Model: 7.1 · Bias: +3.5
What is the 7-day forecast for San Marcos?
05-29
30.3° 19.7°
60.19 mm
05-30
27.2° 21.2°
05-31
31.0° 17.9°
0.06 mm
06-01
31.7° 20.8°
06-02
31.5° 20.9°
06-03
28.8° 21.0°
0.13 mm
06-04
30.2° 21.1°
4.0 mm
Both models agree
Avg diff: 2.9°C
Where are air quality stations near San Marcos?
What cities are near San Marcos?
Get AQI alerts for San Marcos
Notify me when air quality reaches:
Free · No account · Unsubscribe any time
Data sources: AQI from ground-level monitoring stations via AQICN. Weather forecast from ECMWF (IFS & CAMS models). AQI calculated using US EPA standard. Updated 2026-05-29T00:27 UTC.