Subzero Sunrise on Doi Inthanon Draws Crowds with Glittering Frost

Freezing dawns are back on Thailand’s roof, and they are arriving earlier and colder than many park officials expected. Over the long New Year week thousands of holiday-makers braved sub-zero grass temperatures to watch the first light glitter off ice crystals — a shimmering reminder that northern peaks can still deliver genuine winter.

Quick glance: what just happened?

• Doi Inthanon registered a ground chill of −2 °C, the sharpest drop so far this season.

• It was the 27th frost event of the current cold spell, and locals say the ice — or moei khab — now forms almost daily.

• Meteorologists warn the next 6-12 Jan window could be the coldest week of 2026 for the North.

• Tourist flows remain high, but officials urge cautious driving, layered clothing and respect for park rules.

Dawn on Thailand’s rooftop

The first convoy of headlights snaked up Route 1009 well before 04:00. By the time the sky blushed pink above the Mae Ping watershed, visitors were filing past banisters coated in a fragile film of ice needles. Thermometers at the kilometre-43–44 checkpoint read −2 °C, while the ranger station’s lawn hovered near −0.5 °C. Higher still, the summit weather mast clocked 3 °C, cold enough for breath to linger and chatter to cloud the air.

Regular hikers say this is the earliest run of frosts in at least four years. Veteran guide Prasert Jai-song, who has trekked the Kew Mae Pan ridge since the 1990s, calls it “a textbook Siberian surge — dry, dense and absolutely spectacular at sunrise.”

Numbers behind the chill

Long-term records from park headquarters reveal how exceptional the current run has become:

• 29 frost mornings have been logged since 22 Dec 2025, overtaking the 26-day stretch set in 2022.

• Peak grass-top lows hit −6.1 °C on 6 Jan, matching the coldest reading of the last decade.

• Over the past 10 years, annual frost counts oscillated between 21 and 32 events; 2025-26 is already tracking for the upper end of that band.

• In plain terms, a visitor arriving any dawn in early January now faces roughly a 4-in-5 chance of seeing ice.

Climatologists attribute the spike to a parade of high-pressure cells barrelling south from mainland China — each wave reinforcing the chill before the previous one can dissipate.

Why the mercury keeps dropping

Northern Meteorological Centre director Sutthipong Nualkao explains that a potent continental anticyclone has settled over Yunnan and Laos, shunting cold, dry air across the Thai border. Because Doi Inthanon sits 2 ,565 m above sea level, the summit loses heat rapidly at night, and the dew-point often slips below zero. Combine clear skies, light wind and lingering surface moisture, and sublimation paints every blade of grass white by dawn.

Sutthipong adds that climate variability also plays a role. “El Niño winters in Southeast Asia typically feel milder at low elevations, yet they can still deliver intense nocturnal cooling in the mountains.” That paradox leaves frost lovers happy while lowland farmers scratch their heads at warm afternoons.

What travellers need to know

Park authorities have not imposed caps on the daily visitor quota, but they do broadcast a tri-lingual advisory across social media channels:

• Dress in layers — an insulating base, a wind-proof shell and a hat are non-negotiable.

• Stay hydrated; cold air dehydrates as quickly as heat.

• Drive in low gear on the descent; fog can condense into black ice near kilometre 30.

• Respect closed trails; fragile alpine flora suffer when tourists stray off boardwalks searching for the perfect photo.

Medical posts at the headquarters carry blankets, oxygen and ginger tea for visitors who develop altitude chill.

Local economy & ecology

Sub-zero headlines translate into full guesthouses from Chom Thong to Mae Chaem. Hoteliers report winter occupancy north of 95 %, injecting welcome cash into coffee cooperatives and homestay kitchens. Rangers, however, monitor traffic congestion and trash build-up closely; they have already removed 4 tonnes of litter since late December.

On the ecological front, botanists note that Thai cherry blossoms (sakura) respond favourably to cold spells, producing denser flower clusters that draw pollinators in March. At the same time, prolonged frost can nip tender shoots of highland vegetables, trimming yields for local farmers.

Looking ahead

Forecast charts suggest another back-to-back surge of polar air late this week, likely keeping summit lows between 2 °C and 4 °C through 12 Jan, with grass-top plunges flirting once more with −5 °C. If that projection holds, tourists arriving for Children’s Day festivities could witness additional icy mornings — one more reason, perhaps, to pack gloves next to the camera.

For residents in the plains the message is simpler: a fleece at dawn, sunscreen by lunch — and an awareness that Thailand’s brief but brilliant winter is peaking right now high above Chiang Mai.