Notes on the Hanoi weather

Apart from the endless traffic, cheap beer and anxiety-inducing coffee, Hanoi is also home to a bizarre weather cycle. It is one of the few cities in Southeast Asia to feature four distinct seasons. While each season is pleasant in its own way, unprepared travelers might find the Hanoi weather to be a bit of an obstacle. In an effort to get to grips with the capricious Hanoi weather, Chào reached out to Hanoi’s Weatherdude who serves a highly knowledgeable, yet unofficial, English-speaking meteorologist for Hanoi.

Weatherdude has an internet following of nearly 10,000 and provides daily Hanoi weather updates on his Facebook page. His posts brim with useful information, occasionally bordering on the poetic, a recent read: “Beautiful fine weather ahead!… The days ahead in Hanoi will prove to be typically crisp and dry with a sprinkling of sun. Winds from the north. A fine subtle scent of a lonely Himalayan mountain river. Autumn at its finest.”

Another reason for the strange weather is Hanoi’s geographical location. Nestled in the Red River Delta, Hanoi is mostly barricaded from the brunt of most storms by the western Ba Vi mountain range.

Hanoi’s Weatherdude aims to do more than simply talk about the weather. As a former humanities, geography, and environmental studies teacher, he provides an outlet for interested individuals to discuss both science and the arts.

Weather in Hanoi explained

Hanoi’s summers and winters can be lengthy and extreme, leaving little time for autumn or spring. High summer temperatures try to compete with a dull and gloomy winter. The culprit is Hanoi’s strange latitude. “[Hanoi] is not south enough to be tropical and not north enough to be temperate,” says Hanoi’s Weatherdude. “So it’s a mix.”

Another reason for the strange weather is Hanoi’s geographical location. Nestled in the Red River Delta, Hanoi is mostly barricaded from the brunt of most storms by the western Ba Vi mountain range. Most of the heavy rain never makes it over the mountains. However, the delta often tends to trap the wind, resulting in a drier, hotter city temperature. These conditions set the stage for some exciting weather phenomena.

As fall continues into winter, Hanoians begin to don larger coats and brace themselves for dark, chilly skies. Yet recently, global climate change has offered Hanoians a bittersweet gift of shorter cold spells.

When there are storms in Hanoi, they can often be truly epic. “The Laos wind, especially in the first half of summer, dominates from the southwest,” Weatherdude says. “It is very hot and results in fairly dry but spectacular thunderstorms.”

Hanoi by season

Hanoi’s different seasons allow for many different activities. Most travel sites suggest visiting Hanoi either in October/November or March/April. While both are great times for motorbike outings around the countryside, staying in Hanoi in the spring might be a bit of a challenge. Travelers with particular health conditions may be confronted with poor air quality or excessive mold, a symptom of Hanoi’s approaching rainy season. Therefore, the autumn months are best to see Hanoi at its most beautiful.  Events like the Mid-Autumn Festival begin after the peak of the summer heat, with cheery lamps and fireworks lighting up the cooler evenings.

As fall continues into winter, Hanoians begin to don larger coats and brace themselves for dark, chilly skies. Yet recently, global climate change has offered Hanoians a bittersweet gift of shorter cold spells. “Fifteen years ago, some winters were icy cold, around 5-10 degrees Centigrade [41-50 Fahrenheit],” says Hanoi’s Weatherdude. “[Back then], the cold lasted for a few weeks. In the last few years, cold spells last a few days then switch back [and forth]. The north winds are not as pervasive anymore.”

“Powerful lightning storms sometimes rip through the city, obliterating any smog and cleaning the dust from the trees, making Hanoi green again.”

When winter’s grip on Hanoi begins to erode, the summer season dramatically intensifies. Last April, the city witnessed the highest temperatures in over a century. Exhausted coffee shop patrons sweat alongside their glasses of iced coffee. Grandmothers wave big bright fans over themselves and infant grandchildren. In desperation, some even boldly opt to cool off in the murky waters of Hanoi’s lakes.

The heat causes some to sleepily shuffle from one task to the next, with afternoon naps heartily encouraged across the country. Those who do not work in air-conditioned offices may find themselves sleeping underneath the limbs of a colossal tamarind tree or delicately balanced on the seat of their motorbikes. Life moves a little slower from April to August. As Weatherdude puts it: “Summer is about drinking beer and cold smoothies. Best to exercise in the gym.”

Fortunately, the summer takes place during Hanoi’s rainy season, offering Hanoians some respite. “Powerful lightning storms sometimes rip through the city, obliterating any smog and cleaning the dust from the trees, making Hanoi green again,” Weatherdude says. A fan of all aspects of meteorology, Weatherdude has a special appreciation for rainy weather: “The rain drowns out the incessant noise of the city, temporarily calming the chaos. It brings a feeling of calmness and oneness.”

All-in-all the Hanoi weather, provides a merry mix of the hot and cool, the wet and the dry. The mixture of biomes and temperatures is reflected in Hanoi wardrobes. In the summer, a slight breeze causes the edges of a colorful floral sundress to dance, while young men ride through the crowded roads shirtless and sweaty. Once winter creeps through the city, summertime colors and youthful vitality are concealed under heavy sweaters, blazers, and full-body plastic raincoats, large enough to swallow both motorist and motorbike. So, sit back and enjoy the seasonal changes. Variety is the spice of life after all.