Smoke and dust index (OMPS)

Data and trust

UV aerosol index from the OMPS instrument on NOAA-21.

Limits. Coarse (~50 km); does not give ground-level air quality (see PM2.5 series).

How to read it

Below 0 to 5 and above: over ~1 = smoke or dust present, over 2-3 = thick smoke.

Why it matters for Koh Samui

El Nino dry seasons bring fire haze from Sumatra and Borneo that can reach the Gulf of Thailand.

Sources

• ozoneaq.gsfc.nasa.gov

ENSO status now

ONI (NOAA CPC)

+1.80 °C, JJA 2026 (previous +1.39 °C)

RONI (NOAA CPC)

+1.36 °C, JJA 2026

Nino 3.4 weekly (NOAA CPC / OISST)

+3.0 °C anomaly, week of 16 Sep 2026 (SST 29.6 °C)