Vietnams varied climate makes weather predictions anything but reliable.

By DON WILLS on July 07,2017 10:10 AM



Vietnam’s weather patterns are, in a word, complicated.

As with most Asian countries, the climate is governed by monsoons. ‘Monsoon’ actually means wind, but that wind brings along with it rain, and lots of it. Monsoons are triggered by the changing position of the sun in relation to the equator. The severity of a monsoon depends on where the country is positioned in the tropical zone (no more than 23.5º north or south of the equator), its proximity to the open sea, and the existence of mountain chains within that country. In Vietnam’s case, you can tick all those boxes. In addition to the rain, typhoons are a common feature of a monsoon. So too are spectacular displays of lightning and widespread flooding.

Vietnam is subjected to not one but two monsoons a year. The south or south-westerly monsoon hits the country from May to September and the northeast monsoon from October to April. The southern summer monsoon brings rain to the two deltas and west-facing slopes, while the cold winter monsoon picks up moisture over the Gulf of Tonkin and dumps it along the central coast and the eastern edge of the central highlands.

In southern Vietnam, the dry season lasts from December to late April and the rains from May to November. Flooding at this time of year can cause problems in the Mekong Delta. Daytime temperatures in the region rarely drop below 20oC and occasionally hit 40oC during the hottest months of March, April and May. The climate of the central highlands generally follows the same pattern, though temperatures are cooler, especially at night. Again, the rains can disrupt transport, wash out roads, and cut off the more remote villages.

Along the central coast the rainfall pattern is influenced by the northeast monsoon. Around Nha Trang the wet season kicks off in November and continues to December. Further north, around Hue and Danang, the rains last a bit longer, from September to February. Temperatures reach their maximum, often in the upper 30s, from June to August. The northern stretches of this coastal region experience a more extreme climate, with a shorter rainy season peaking in September and October and a hot dry summer.

Northern Vietnam is generally warm and sunny from October to December, after which cold winter weather sets in, accompanied by persistent mists that can last for days. Temperatures begin to rise again in March, building to summer maximums that occasionally reach 40oC between May and August, though average temperatures in Hanoi hover around a more liveable 30oC. However, summer is also the rainy season, when heavy downpours render the low-lying delta area almost unbearably hot and sticky, and flooding is a regular hazard. The northern mountains share the same basic pattern, though temperatures are considerably cooler and higher regions get regular ground frosts during the winter, from December to February.

Now, the logical thing to do is to avoid visiting a region during the rainy season, right? But that’s not as easy as it sounds. For one thing, if you ask a Vietnamese person when the rainy season falls in his or her own area, you’ll come up with a lot of conflicting answers, ranging from tenuous, vague, unsure, ambiguous to imprecise. Why on earth the uncertainty, I wonder? Well, it’s possible that the person you asked is the vague, unsure, ambiguous, imprecise type. Or more likely, it’s because when it comes to weather, no-one can be certain. In this age of global warming, climate change, and regular visits from El Nino, weather patterns are getting increasingly unpredictable.

So it’s on the cards that sooner or later you’ll find yourself somewhere, sometime, slap-bang in the middle of a seasonal deluge. Heralded by a crack of lightning loud enough to wake you and rattle your window panes, a tropical rainstorm is something to behold. It’s difficult to describe the experience of being caught out in the open during a sudden downpour. Picture someone upending countless buckets of water over your head; picture wading ankle-deep through water with visibility barely more than an arm’s length in front of you; picture stripping to your underwear before re-entering your front door, wringing a cupful of water from each sock; picture extracting damp banknotes from your sodden wallet and drying them with a hair dryer.

But if you ventured outside without taking a raincoat, you’ve only got yourself to blame. A word of wisdom about raincoats here. There are two types of raincoats: the most popular are more like ponchos than raincoats, and are only semi-successful at keeping you dry. On a motorbike, they flap wildly around your legs, and should you give them anything more than a sideways glance they’ll tear. The more sensible (but more expensive) raincoats are a combination of waterproof trousers and a hooded jacket. Unlike the poncho variety, these ones keep you dry even in the heaviest of downpours.

Now here’s another complication connected with the weather in this country: typhoons. The coast of central Vietnam is the zone most likely to be hit by typhoons, bringing torrential rain and hurricane-force winds. They’re notoriously difficult to predict, but in general the typhoon season lasts from August to November. And their effects can be devastating. The first two typhoons to hit Vietnam in 2016 caused $300 million worth of damage. In October last year, Typhoon Sarika killed 24 people in Quang Binh province in just a few short hours.

Typhoons rarely hit without warning. They are relatively slow-moving over the oceans and countries in a typhoon’s path can be alerted to batten down the hatches and stand by. One of the deadliest typhoons ever to come Vietnam’s way (in fact the strongest storm ever recorded) was Typhoon Haiyan in 2013. It began in the Philippines on November 6, where it left more than 6,300 dead, and proceeded to slowly make its way west. On November 8, then-Prime Minister Nguyen Tan Dung activated the highest state of preparedness in the country. Approximately 600,000 people in southern and central provinces were evacuated, while a further 200,000 were evacuated in northern provinces. Alerts were sent to 85,000 seagoing vessels. Hundreds of flights were cancelled around the country and schools were closed.

Fortunately for Vietnam, by the time Typhoon Haiyan finally made landfall in the northern province of Quang Ninh on November 11, it had weakened considerably. Even so, sustained winds of 120 km/h, the equivalent of a Category 1 hurricane, were recorded. Although it produced heavy rainfall of up to 30 cm in some areas and strong winds, damage was relatively limited.

So there you have it; the whole complicated deal on Vietnam’s weather. Maybe the lesson to be learned from all this is when you go out, take both sunscreen and a raincoat with you.

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Rambling around

10AM, 07 June

Getting from here to there in vietnam is, for the most part, quite a straightforward affair.

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