Chiang Mai Weather & Climate a city for all seasons

Volumes could be written on Chiang Mai’s multitude of virtues but as a holiday destination and especially as an adopted home, the milder climate of Northern Thailand is a major draw. Unlike so many other places in the Tropics which suffer from stifling hot and sticky conditions year round, the Chiang Mai weather is decidedly seasonal thanks to its northerly latitude, modest altitude and distance from the sea. And while the arrival and the length of which do vary somewhat from one year to the next, each of Chiang Mai’s three seasons brings its own joys as well as woes. So, besides checking the Thai Meteorological Department’s current weather and 7 day forecast for Chiang Mai, what can you expect from the seasons here and is there such a thing as a best time to visit Chiang Mai?

It’s A Scorcher Out There – The Hot Season

Be in Chiang Mai any time from late February to the middle of May or thereabouts and you can bank on little more than a smattering of rain and daytime temperatures in town regularly topping 30 degrees with the mercury hitting an all-time high of a positively sizzling 42.4°C (108.3°F) back in 2005. At this time of year when indoor spaces trap masses of heat during the day and still feel like an oven long after the sun’s vanished below the horizon, no amount of fans will cut it and the only way to find lasting relief is to befriend the A/C remote control…and to hell with the cost! Or else, you’ll roast in your own juices with the end all the quicker if you happen to be staying in a west-facing room on a higher floor! And it’s not all hot air either since between the hours of around 10AM and 4PM throughout most of the hot season, the intensity of harmful solar radiation striking Chiang Mai is a flesh-burningly extreme 11+ on the World Health Organisation’s UV Index scale!

So rather than simply having to grin and bear it, what exactly can you do to protect yourself and find comfort at this unforgiving time of year? Well, before heading outdoors, take a leaf out of the Thais’ book and dust yourself with anti-perspirant talcum powder containing cooling agents like menthol before dressing in something loose-fitting, lightweight and breathable covering as much of the body as possible then apply a water-resistant sunscreen with an SPF of 30+ to exposed skin. And for when out and about, wear well fitting, decent quality sunnies, keep to the shade, limit activity to early mornings and after sunset, use an umbrella or don a wide-brimmed hat, stay hydrated and go easy on the alcohol and caffeine, eat little and often (ideally salty or sugary food but steer clear of spicy fare), take it slow and if all else fails and you’re in danger of self-combusting, duck into the nearest 7-Eleven to enjoy a welcome blast of bone-chilling air-con and a disposable ice-cold ‘Refreshing Towel’!

Yet even practicing sun and heat avoidance strategies like a pro, the hot season here unleashes an added challenge. Normally from the last week in February to the first week of April, farmers right across Northern Thailand, Laos and Myanmar (Burma) slash ‘n’ burn their way through forests and crop fields morning, noon and night sparking not just the vegetation but also a blaze of controversy. Posing a serious health risk, air quality in Chiang Mai goes completely to pot getting so polluted it makes that in Beijing seem pristine and, when the smog’s at its worst, parts of the blighted Rose of the North smack of an almost post-apocalyptic scene! To get through Chiang Mai’s smoky season relatively unscathed, the best safeguard is to wear a construction grade face mask or respirator and definitely so if sensitive or allergic to airborne contaminants.

As a not-so-small mercy for the parched, sweltering and, at times, unwholesome conditions of the season, the hottest month of the year in Chiang Mai coincides nicely with the Thai New Year (Songkran) and, for a few days in mid-April, the chance to find blessed respite from the searing temperatures by joining in the wettest and wildest water fight on the planet!

Break Out The Waterproofs – The Rainy Season

Chiang Mai Weather come mid-May (‘til the end of October), monsoon air absolutely loaded with moisture streams in from the Indian Ocean producing energy-sapping mugginess and, apart from a slight lull in June, periodic rainfall in Chiang Mai. But the largely overcast heavens don’t open every single day and when they do, it’s seldom an all day affair. With the steady build up of heat and humidity by the afternoon or evening, dramatic storms can develop heralded by violent gusts of wind out of nowhere, sinister-looking dark clouds appearing overhead and the odd rumble of thunder. The torrential downpours that follow rarely last very long, though, before downgrading into a drizzly shower or fizzling out altogether.

With no shortage of standing water, this is the time of year when you’re at greatest risk of catching potentially life-threatening dengue fever from day-flying, people-loving female Aedes mosquitoes so use plenty of insect repellent, cover up from head to toe and avoid being out-of-doors around dusk and dawn when they’re most active and hungry for blood! And the storm drainage system here isn’t the best in the world and the city’s sat in bowl-shaped valley so it’s hardly surprising that Chiang Mai experiences flash flooding during the heaviest deluges with the areas hardest hit either side of the Ping River. Every now and again, it buckets down so much as to leave roads and buildings submerged in waist-deep water and knocking out power not just for an hour or two but for days on end prompting some enterprising locals to brave the elements by taking to paddle boats in order to get around!

Except for a stream of visitors from the rain-starved Middle East who make the pilgrimage to be in Chiang Mai expressly for the soggiest months of August and September, it’s low season so the city can feel blissfully light on human traffic with maximum availability of seats and beds, shops overflowing with cheap and cheerful rain ponchos and cash-strapped vendors only too happy to do deals. Not to mention being the time of year when Chiang Mai’s natural landscapes are at their most lush, buzzing with life and because the rain washes away the dust, the air feels wonderfully fresh with crystal clear skies and the occasional sunny spell to enjoy the best far-reaching vistas of the surrounding mountains.

Time To Wrap Up – The Cool Season

From early November to late February is Chiang Mai’s winter. Although a touch of frost isn’t uncommon on the highest ground, don’t expect any snow as temperatures almost never dip below zero. Instead, you can look forward to perfectly balmy (think low to mid twenties), sunshiny days with azure blue skies filled with white fluffy clouds, virtually no rain and cool, crisp, starry nights.

Little wonder then that this is the peak tourist season in Chiang Mai so seats and beds fill up fast, prices rise and crowds gather. And it can get quite nippy after dark particularly during the chilliest month of January. So, for after sundown and first thing in the morning, even the hardiest of foreigners will likely need to slip on an extra layer at this time of year.

But it’s not just people that thrive in these near ideal conditions; so too do Chiang Mai’s wealth of flowering plants and at certain spots within the nearby Doi Suthep-Pui National Park, you’ll have the opportunity to witness the dazzling floral extravaganza of native Himalayan cherry blossoms in full bloom!

What’s your most favourite time of year in Chiang Mai and why? Which season do you like least and for what reasons? We’re curious to know so feel free to share your thoughts by posting a comment below!