Thailand PM2.5 Checker

PM2.5 in Long, Phrae now

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PM2.5 statistics for Long, Jun 2025 to Jun 2026

Over 365 days with data the average was 23.7 µg/m³ (Good), and 46 of those days went over the daily limit of 37.5.

Yearly average23.7Good
Dustiest day123.94 April 2026
Cleanest day6.123 July 2025
Days over 37.546of 365 days
Dustiest monthApril75.4
Cleanest monthSeptember8.7

Monthly average

025507527Jan29Feb53Mar75Apr17May11Jun10Jul10Aug9Sep11Oct13Nov20DecDaily limit 37.5

Days in each air quality band

  • Excellent191 days
  • Good68 days
  • Moderate60 days
  • Unhealthy for sensitive groups23 days
  • Unhealthy23 days

About PM2.5 data for Long

PM2.5 for Long, Phrae comes from Health Promotion Hospital Sob Pad, Lampang, the nearest station in the Air4Thai network. Daily history is available for 2016-2026.

PM2.5 levels

LevelPM2.5 (µg/m³)
Excellent0-15
Good15.1-25
Moderate25.1-37.5
Unhealthy for sensitive groups37.6-75
Unhealthy75+

Frequently asked questions

Which station measures PM2.5 for Long, Phrae?

Long uses the nearest Air4Thai monitoring station, Health Promotion Hospital Sob Pad, Lampang, about 19 km from the district centre. The page shows this distance next to every reading.

At what PM2.5 level should I wear a mask?

Above 25 µg/m³ (the moderate level, 25.1 to 37.5) at-risk groups should wear a surgical mask outdoors for long periods. From 37.6 to 75 the air starts to affect health and an N95 mask is advised outdoors. Above 75 avoid outdoor activity and wear an N95 mask whenever you go out.

How often is the data updated?

Readings come from the Pollution Control Department's Air4Thai feed and are refreshed every hour. If a station has not reported for over 3 hours the page marks the reading as old.

Can I see past PM2.5 for Long?

Yes. Open the daily history on the page for a chart of PM2.5 from the nearest station. Stored history covers 2016-2026.

What is AQI and how is it different from PM2.5?

AQI (Air Quality Index) is a single number calculated from several pollutants: PM2.5, PM10, ozone, carbon monoxide, nitrogen dioxide and sulphur dioxide. The pollutant with the worst value in that hour sets the AQI. The Pollution Control Department's bands are 0 to 25 excellent, 26 to 50 good, 51 to 100 moderate, 101 to 200 unhealthy for sensitive groups and 201 and above unhealthy. PM2.5 is one pollutant only: the concentration of particles up to 2.5 microns across, measured in µg/m³. This site uses PM2.5 as its main value and for card colours, and shows AQI as supporting data, so the two can fall in different bands.

Latest PM2.5 Long, Phrae

PM2.5 in Long, Phrae is 14.3 µg/m³, level Excellent. Reading from station Health Promotion Hospital Sob Pad, Lampang, about 19 km away, measured 23 Oct 2026, 17:00 (this may be out of date).

Values come from the station nearest to each district and update hourly.