Phuket · readings, context & method
Phuket air quality by month
Which months have had cleaner air in Phuket? Compare the months actually recorded here, including the days we could not measure. Each row is a particular month and year, not a prediction of the next season.
What the available history can tell you
The available record runs from 28 March 2025 to 18 October 2026. Across this record, 181 of 567 complete closed days were Not Good (AQI above 50). Partial and missing days are excluded from that count.
This is a record of available Phuket PM2.5 observations. It is too limited to establish a long-term monthly climate pattern or guarantee air quality for a future visit.
Not Good means above the US AQI Good range: Moderate or worse. It is not a separate EPA category.
Recorded PM2.5 and AQI, month by month
Monthly PM2.5 is the equal-weight mean of available daily concentrations, including partial days; we then convert that concentration to AQI. It is not an average of daily AQI scores. Lower concentrations indicate less measured fine-particle pollution.
Among the 17 closed months with every day complete, July 2026 had the lowest recorded monthly mean PM2.5 (3.8 µg/m³), and April 2026 had the highest (13.5 µg/m³). This comparison excludes incomplete months and describes this archive only.
| Month | Mean PM2.5 µg/m³ | AQI from mean PM2.5 | Complete / closed days | Not Good AQI above 50 · complete days only | Hour coverage |
|---|---|---|---|---|---|
| October 2026Month in progress | 11.518/18 days observed | 55Moderate | 17 / 17Today is provisional | 76.5%13 of 17 complete days | 94.9%Covered hours / expected hours |
| September 2026All days complete | 6.230/30 days observed | 34Good | 30 / 30Every day complete | 10.0%3 of 30 complete days | 100.0%Covered hours / expected hours |
| August 2026All days complete | 6.231/31 days observed | 34Good | 31 / 31Every day complete | 19.4%6 of 31 complete days | 100.0%Covered hours / expected hours |
| July 2026All days complete | 3.831/31 days observed | 21Good | 31 / 31Every day complete | 6.5%2 of 31 complete days | 100.0%Covered hours / expected hours |
| June 2026All days complete | 4.030/30 days observed | 22Good | 30 / 30Every day complete | 0.0%0 of 30 complete days | 100.0%Covered hours / expected hours |
| May 2026All days complete | 4.431/31 days observed | 24Good | 31 / 31Every day complete | 3.2%1 of 31 complete days | 100.0%Covered hours / expected hours |
| April 2026All days complete | 13.530/30 days observed | 59Moderate | 30 / 30Every day complete | 86.7%26 of 30 complete days | 100.0%Covered hours / expected hours |
| March 2026All days complete | 12.131/31 days observed | 57Moderate | 31 / 31Every day complete | 71.0%22 of 31 complete days | 100.0%Covered hours / expected hours |
| February 2026All days complete | 9.028/28 days observed | 49Good | 28 / 28Every day complete | 39.3%11 of 28 complete days | 100.0%Covered hours / expected hours |
| January 2026All days complete | 12.931/31 days observed | 58Moderate | 31 / 31Every day complete | 96.8%30 of 31 complete days | 100.0%Covered hours / expected hours |
| December 2025All days complete | 11.231/31 days observed | 55Moderate | 31 / 31Every day complete | 64.5%20 of 31 complete days | 100.0%Covered hours / expected hours |
| November 2025All days complete | 12.230/30 days observed | 57Moderate | 30 / 30Every day complete | 50.0%15 of 30 complete days | 100.0%Covered hours / expected hours |
| October 2025All days complete | 5.231/31 days observed | 29Good | 31 / 31Every day complete | 6.5%2 of 31 complete days | 100.0%Covered hours / expected hours |
| September 2025All days complete | 4.330/30 days observed | 24Good | 30 / 30Every day complete | 0.0%0 of 30 complete days | 100.0%Covered hours / expected hours |
| August 2025All days complete | 6.431/31 days observed | 36Good | 31 / 31Every day complete | 16.1%5 of 31 complete days | 100.0%Covered hours / expected hours |
| July 2025All days complete | 5.331/31 days observed | 29Good | 31 / 31Every day complete | 6.5%2 of 31 complete days | 100.0%Covered hours / expected hours |
| June 2025All days complete | 7.630/30 days observed | 42Good | 30 / 30Every day complete | 30.0%9 of 30 complete days | 100.0%Covered hours / expected hours |
| May 2025Incomplete daily coverage | 6.731/31 days observed | 37Good | 30 / 31Incomplete month | 20.0%6 of 30 complete days | 98.0%Covered hours / expected hours |
| April 2025All days complete | 6.330/30 days observed | 34Good | 30 / 30Every day complete | 16.7%5 of 30 complete days | 100.0%Covered hours / expected hours |
| March 2025Archive starts mid-month | 28.94/31 days observed | 88Moderate | 3 / 31Incomplete month | 100.0%3 of 3 complete days | 10.5%Covered hours / expected hours |
On narrow screens, scroll the table sideways. Expected hours are 24 per calendar day through today; the current day has not finished. Missing days at the start of the first archive month count as missing coverage. A dash means no usable value, not zero pollution.
Compare pollution and coverage together
Read the denominator
“Not Good (AQI above 50)” counts only closed days with at least 18 covered hours. A month with two complete days can have a very different evidence base from one with 30. There is insufficient evidence for a full-month comparison wherever complete days are missing; we show those months rather than silently filling their gaps.
Look beyond the monthly mean
A monthly mean can hide short pollution episodes and cleaner days. Open a month to see its daily values, then use the interactive history to inspect a particular week or day. The daily archive also provides CSV downloads for checking the numbers yourself.
The archive combines older published hourly observations with this site's saved two-minute calculations from 18 October 2026. Monitor availability and input processing can change. These are observations from available locations, not an area-weighted survey of the whole island. Read the calculation and coverage method before treating changes as a trend.
Questions about Phuket air quality by month
Which month is best for clean air in Phuket?
This archive can identify lower measured pollution in particular recorded months. It cannot establish the best future month to visit: it is a limited historical record, not a multi-year climatology or forecast. Compare the actual years and coverage above, and check current conditions nearer the time.
Does a Good monthly AQI mean every day was Good?
No. The monthly value converts the average daily PM2.5 concentration. Some individual days may be higher. Use the count of complete Not Good days (AQI above 50) and the linked daily records to see the variation. The US EPA's 2024 PM2.5 scale places the Good band at AQI 0–50, through 9.0 µg/m³; this site's preserved conversion is explained in the method guide. EPA's 2024 AQI update.
Why is a month marked incomplete?
The archive may begin partway through it, observations may be missing, or too few hours may be covered on some days. The current month is also unfinished. None of those gaps are treated as clean air, and an unfinished day never enters the complete-day percentage.
Can these numbers prove why pollution changed?
No. This record measures concentrations; it does not identify the cause of an episode. Weather, emissions and changes in the observation network need separate evidence. The table does not attribute a high or low month to a particular cause.