Air Quality Index (AQI)

Air pollution is a problem all over Thailand, but in burning season (usually Feb - April) the pollution in Chaing Mai gets particularly bad as there is no wind to take the smoke away.

During this time the Health Office and Athletic Department closely monitor pollution levels throughout the day by checking the Air Quality Index (AQI). From this we are able to make decisions about any activity restrictions at school.

The Health office will send out an email 4 times a day (6am, 9am, 11am, 1pm) to let you know if any restrictions are in place, these emails will simply have the AQI color and any restrictions in the subject line.

The Athletics Department will make a decision at around 1pm and will notify coaches and parents if any after school sports activities are cancelled. Please do not refer to your own personal monitoring systems or ask other members of staff for direction. This really helps to keep us all on the same communication page.

CMIS Air Quality Standards and Activity Level Guidelines are aligned with the Environmental Production Agency of the US Government are are included at the bottom of this email for your information.

N95 masks are available for purchase for 50B each from the Health Office or the school shop. All staff will be issued with 1 free mask, which we will put in your mail box in due course. Please wear this mask if you are on duty when the AQI is in the red zone.

Red days:

PS - Please follow the indoor recess procedures.

Before school - The auditorium will be open for PS students

Recess - students are to remain in their homeroom classroom

Lunch - students can go to the cafeteria to eat lunch and then return to their classrooms

MS/HS - Please read the updated supervision duties

Before school/recess and lunch - Students can sit in the cafeteria, library or outside as long as they are not running or doing exercise

Purple days:

An announcement will be made over the school system and all students will be given a mask to wear when they are outside walking between classes.

PS procedures are the same as for Red days

MS/HS - students can no longer sit outside and should be directed to an enclosed space (eg cafetera, MP room, library)


The air purifiers in your classrooms will be turned on by the Thai staff first thing in the morning, but we as that you please turn them off at the end of the day when you leave.

CMIS Air Quality Policy and Procedures