Welcome to Chiang Mai’s infamous burning season, or as locals call it, ‘roodoo mok khwam’ (ฤดูหมอกควัน) – literally ‘smoke season. It’s when our beloved city’s surrounding mountains trap a cocktail of smoke and pollution in a breath-stealing embrace.

Picture Doi Suthep vanishing behind a curtain of gray, the sun reduced to a dim red orb. That’s just what you see. What you feel? That’s another story entirely.

But don’t panic! As a long-time resident who’s survived more burning seasons than I care to count, I’m here to give you the unvarnished truth. From its causes to survival tips (and yes, how to enjoy Chiang Mai despite it), consider this your ultimate, no-holds-barred guide.

So, grab your N95 mask and let’s dive into the smoky reality of Chiang Mai’s most controversial season. Whether you’re planning a visit, considering a move, or just curious about life in a real-life smoke machine, we’ll get you the facts. Time to clear the air about the burning season, shall we?

When is Burning Season in Chiang Mai?

Now, here’s where it gets tricky. While some sources claim the burning season starts as early as January, in my experience, things don’t get truly apocalyptic until February and March.

Month-by-month Burning Season Breakdown:

  • January: Early signs of burning may appear, but air quality is generally still good.
  • February-March: Peak burning season. Air quality is at its worst during these months.
  • April: Conditions start to improve, but can still be problematic.
  • May: Air quality usually returns to normal as the rainy season begins.

Planning your visit? Here’s what you need to know:

  1. Short-term visitors: If your trip is flexible, aim for October to December for the best weather and air quality. If you must visit during burning season, plan for more indoor activities.
  2. Digital nomads: Most digital nomads leave Chiang Mai in January and February to enjoy the beach in Koh Phangan, Hoi An, or Bali.
  3. Long-term expats: Consider taking a holiday during the worst weeks, typically in March. If staying, invest in good air purifiers for your home and workplace.

Remember, while these are general guidelines, the intensity of the burning season can vary year to year. It’s always a good idea to check current conditions and forecasts when making your plans. 

Last year we booked a Vietnam beach getaway for late February and Chiang Mai ended up having the best air quality in all of Thailand during those two weeks. So you never know.

The intensity of burning season can vary significantly from year to year, influenced by factors such as:

  • El Niño and La Niña weather patterns
  • Effectiveness of burning bans and enforcement
  • Regional cooperation in controlling fires

While some years may see relatively mild pollution, others can be severe, with extended periods of downright hazardous air quality.

When to come back to Chiang Mai?

Plan your visit for early April. The smog is significantly reduced by then. Besides the clear skies, April also brings the world-famous Songkran water festival. Songkran is a traditional Thai New Year celebration featuring a citywide water fight, vibrant processions, and cultural performances. When I say city-wide I mean city-wide. It’s such a fun experience.

Songkran water festival is crazy fun and worth coming to Chiang Mai for.

How Bad Does Burning Season in Chiang Mai Get?

Bad enough that it regularly gets reported on in the international press.

The severity of Chiang Mai’s burning season is best understood through hard data and its real-world impacts on air quality and health.

What is Chiang Mai’s Air Quality Like During Burning Season?

During peak burning season, Chiang Mai’s Air Quality Index (AQI) can reach alarming levels. AQI readings regularly fall in the 150-200 range, classified as “Unhealthy”. Spikes above 300 AQI are not uncommon, entering the “Hazardous” category. 

There have been instances when Chiang Mai’s AQI has surged to as high as 700 or even more, temporarily earning it the unfortunate distinction of being the most polluted city in the world. 

What is the air quality index (AQI)? | Chart by IQAir

During these peak times, the city is shrouded in a dense, smoky haze that limits visibility and permeates the air with a thick, burning smell. It’s a stark contrast to the otherwise pristine and serene atmosphere that Chiang Mai is known and loved for.

To put this all in perspective, the World Health Organization (WHO) recommends a maximum daily exposure to PM2.5 (fine particulate matter) of 15 μg/m3. During burning season, Chiang Mai’s PM2.5 levels can reach 200 μg/m3 or higher.

Visibility Impact: Bye Bye Doi Suthep

The pollution severely affects visibility in the region. On bad days, visibility can drop below 1km, with landmarks like Doi Suthep mountain often disappearing from view. In extreme cases, the haze can be thick enough to cause flight cancellations at Chiang Mai International Airport.

Not our photo. Credit goes to Redditor OM3N1R 📸🙏

What Are the Health Effects of Burning Season?

The most common complaint is a kind-of head stuffiness. It feels like you have a cold without the runny nose.  

People also report short-term effects like irritation of the eyes, nose, throat, and sinuses. That comes with coughing, sneezing, headaches, dizziness, and anyone with asthma and allergies gets it worse. 

Those of us who live here tend to worry about the long-term effects like cancer, as studies suggest an increased risk of respiratory diseases and potential cardiovascular issues for long-term exposure. 

Hospital visits spike during this period, with complaints ranging from minor irritations to serious respiratory distress, particularly affecting vulnerable groups such as children, the elderly, and those with pre-existing respiratory conditions. 

There is also the psychological effect of being stuck indoors and living in smog for three months. 

Not fun.

How Bad is Chiang Mai’s Smoke Season Comparatively?

Chiang Mai’s air quality is excellent for eight months of the year, but two months are meh, and  two months can see pollution levels that are just appaling. 

In recent years, Chiang Mai has occasionally ranked as the world’s most polluted city during peak burning season, surpassing notoriously polluted urban centers in China and India.

While northern Thailand faces one of the most challenging burning seasons in the region, it’s pretty bad all around us. Bangkok, despite being closer to the coast, suffers from poor air quality that often rivals or even surpasses Chiang Mai’s. 

Island cities like Phuket and Singapore offer consistently cleaner air but even they have the occasional drift of haze. Our mountainous and rice-farming neighbors in Laos, Myanmar, and Cambodia suffer as badly as Thailand this time of year. And you would think our Southeast Asian neighbors on the coast or islands would fare better, but Vietnam, Malaysia, and even Indonesia suffer from this seasonal haze issue.

Why Does Burning Season in Chiang Mai Happen? 

Alright, what’s behind all this? I’m not a scientist or a journalist – but I have been living through this reality year after year and my wife Lily grew up here. Her family still farms in the countryside, and we live right up against the national parks so we’ve got a front-row seat to this whole burning season drama.

The Perfect Storm of Geography and Weather

The main reason burning season in Chiang Mai happens is because of geography and weather. We’re living in a valley surrounded by mountains, which is gorgeous most of the year. But come dry season we get stuck in with whatever air pollution’s around.

During these months, a high-pressure system settles over us. There’s basically a giant lid of air on the Chiang Mai valley. All the smoke and dust that gets created? It’s got nowhere to go. 

Agricultural Practices and Economic Realities

Yes, a lot of that smoke comes from farmers burning their fields. But before you go pointing fingers, let me tell you about Lily’s family and countless others like them.

These folks are just trying to make a living. Burning fields is quick, it’s cheap, and it gets the job done. The alternative? Tilling all those rice stalks back into the soil. It’s backbreaking work that takes time and money these farmers don’t have.

Lily’s family are big into organic farming, so into it that they get pretty preachy with their neighbors. They’ve told us that people listen and the knowledge of better ways to do things is out there, but they still choose the option that comes with less risk and more financial reward.

And here’s something most people don’t realize: those burning bans are actually making the problem worse in some way. We’re seeing fields burn in December or January now, as farmers race to get one more crop in before the rains and the burning bans kick in. It’s not because they don’t care; it’s because they need to survive.

But it’s not all about farm fields. Forest fires are a huge part of the equation. Some are natural, sure, but most are started by people, whether it’s for hunting, foraging, or other reasons. It’s hard to catch the perpetrators because a common tactic is to set fireworks on a long fuse and then just leave it.

If you want to dig into “the science” and research, this is a great article by Dr. Artima Medical Clinic with loads of charts and everything.

Regional and Urban Contributions to Air Pollution

And let’s not forget our neighbors. Myanmar, Laos – they’re dealing with the same issues. That smoke doesn’t need a passport to pay us a visit. While Thailand’s taking this issue seriously and has put resources behind managing forest fires, our poorer neighbors can’t afford to do the same and we just have to live with that.

Before my fellow city dwellers get too comfortable, we’re not off the hook. Our cars, the constant construction, general urban pollution – it all adds up. We’re throwing our own ingredients into this smoky soup.

Here’s a twist for you: thinking of escaping to the countryside for some fresh air? Think again. It’s often worse out there. You’re closer to the burning sources, without even the dubious protection of city buildings.

Will Burning Season Ever Not Be a Thing?

It’s not all bad news. Things are changing, albeit slowly. More farmers are learning about alternatives to burning. The government’s starting to take real action. It’s not perfect, but it’s progress.

Understanding all this doesn’t magically clear the air, but it helps you get why this isn’t a simple problem with a quick fix.

Kris & Lily, Smoggagedon 2019

8 Essential Safety Tips for Surviving Burning Season

Before we dive into the tips, let me share a bit of our personal experience. For the last two years, we’ve stuck around Chiang Mai during burning season, taking only short trips away. 

I won’t lie – it was tough, especially hearing our little Fiona develop a cough because she loves to play outside. Last year, with Melody born in March, getting away was just too much hassle.

This year? We’re definitely heading to a beach with some friends. (Psst… if you want a great deal on accommodation, you can sublet our house. Just saying!)

For those sticking it out in Chiang Mai, here’s how we do it. We’ve got a Xiaomi Max air purifier for our gigantic living room, and smaller ones for each bedroom and my office. We keep these running to maintain AQI below 20 indoors. Trust me, this investment makes a world of difference.

Now, onto our Chiang Mai burning survival tips:

  1. Monitor Air Quality: Use apps like AirVisual. It’s like checking the weather, but instead of deciding if you need an umbrella, you’re deciding if you need a hazmat suit.
  2. Invest in Air Purifiers: Put them all over your house and keep them running. Your lungs will thank you.
  3. Wear N95 Masks: Fashion meets function. Nothing says “I’m a Chiang Mai resident” like coordinating your N95 with your outfit.
  4. Limit Outdoor Activities: Especially during peak pollution hours in the early morning. Your jog will just have to move inside on the gym treadmill.
  5. Patronize Businesses That Use Air Purifiers: There’s a locally made app that tracks which businesses use air purifiers. Great for choosing a gym or cafe to go to.
  6. Keep Windows Closed & Use Air Conditioning: It’s really frickin’ hot this time of year too, so budget suitably for that aircon bill.
  7. Consider a Short Trip: It’s not running away, it’s a tactical retreat.
  8. Stay Healthy: Hydrate with plenty of water, eat an anti-inflammatory diet, and listen to your body. If you feel unwell, be responsive!

Should You Visit Chiang Mai During Burning Season?

If you’re not into wearing a gas mask as a fashion statement, consider heading south. Krabi, Phuket, or Koh Phangan are all solid options. Just don’t expect us Chiang Mai locals to admit that any of these places are actually better than our beloved city.

If you want to hear more horror stories (or maybe find some coping strategies), check out the Chiang Mai subreddit during burning season. It’s a mix of gallows humor, genuine concern, and the occasional ‘It’s not that bad’ contrarian. You know, typical Reddit.

Living through Chiang Mai’s burning season is no small thing. Here’s the BIG thing, though: this city, with all its flaws and smoky days, is still one of the most fun and livable places in the world.

Is it perfect? Far from it. 

The burning season is a thorny issue rooted in geography, economics, and tradition that, unfortunately, has no end in sight. But that’s just one red flag amid a sea of green ones.

For short-term visitors, if you can avoid February and March, do it. Come in the cool season or during the rains – you’ll see Chiang Mai at its best. If you must visit during burning season, don’t write us off completely. Book a place with an air purifier, plan some indoor activities, and we guarantee you’ll still have a great time..

Digital nomads, you’ve got it easier. Time your stay to enjoy the best of Chiang Mai, then join the exodus to the beaches when the air gets thick. It’s the perfect excuse for a working vacation in Koh Phangan or Bali.

And for us long-termers? We adapt. We invest in air purifiers, plan strategic getaways, and think about why we fell in love with this place. The burning season is tough, but when the first rains wash away the smoke and Doi Suthep emerges from its hazy shroud, we remember why Chiang Mai is worth it all.