Phuket Air Quality in September 2025

In September 2025, Phuket’s observed daily PM2.5 averaged 4.3 µg/m³ (AQI 24 after conversion), across 30 of 30 days with data. 0 of 30 complete days were Not Good (AQI above 50).

Table dates: 1 September 2025 – 30 September 2025 (Phuket time, UTC+7). AQI 0–50 is Good; 51–100 is Moderate. Not Good means above the US AQI Good range: Moderate or worse. It is not a separate EPA category. Missing and partial days are excluded from the Not Good frequency.

Explore these dates with the AQI / PM2.5 chart and calendar →

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How these historical readings are calculated

Daily PM2.5 averages the available hourly concentrations in Bangkok time, then converts that concentration using this site's original AQI calculation. Weekly, monthly and yearly values average the available daily concentrations before conversion, including partial days. AQI numbers are never averaged.

From 18 October 2026, each locally collected reading averages the two highest fresh PM2.5 observations, or uses one when only one is eligible. These saved calculations are averaged within each hour. An hour needs at least 23 of 30 two-minute samples to qualify for coverage; less-covered hours remain visible as estimates. Earlier provider history selects the two highest available station concentrations for each hour, with the same one-station fallback. A complete day has at least 18 covered hours; today is always provisional.

The historical provider may supply corrected concentrations where the original live feed supplied raw values; unavailable original inputs cannot be reconstructed. This is a PM2.5 indicator, not an official multi-pollutant AQI or EPA NowCast.

Read the calculation and coverage methodology · Compare Phuket air quality by calendar month