The key difference for travelers to the Mekong is that, during the high water season, the Tonle Sap lake becomes accessible to river cruise ships because the Tonle Sap river connecting the lake to the Mekong swells. Guests who travel on the Aqua Mekong during this period can visit floating villages and the Prek Toal Bird Reserve. Ships can also dock on the shores of the lake, just 45-minutes away from Siem Reap.

The eight-month low water season from December through to mid-August sees a lower water level in the Mekong and reduced flows. The Tonle Sap lake is inaccessible from the Mekong via the Tonle Sap river during this period, making the lake inaccessible to river cruise ships. That said, this period is also an opportunity to see a quieter side of local life on the Tonle Sap lake.

This brings us to an important point: Why do other river cruise lines still claim to sail to and from Siem Reap during the low water season? That’s because the itineraries that do so require guests to endure an unpleasant six hour road journey by road from a distant port on the Mekong to Siem Reap.

Aqua Mekong, on the other hand, only docks at Phnom Penh in Cambodia (other than Ho Chi Minh City in Vietnam) during the low water season while offering itineraries that still take you upriver to amazing excursions on the Tonle Sap river. Docking at Phnom Penh’s city centre lets travelers to take a quick 45-minute flight from the capital to Siem Reap if they wish, compared to a back-breaking six hour bus ride on uneven country road.

All said, it’s helpful to remember that high-low water seasons may vary unexpectedly from year to year, and river cruises may have to adjust their itineraries in short notice. Aqua Expeditions keeps guests who travel during the transition period informed of any last-minute changes.

 
In the warmest month of March, this figure may climb as high as 38°C (100°F). Coincidentally, the heat makes cruising the Mekong even more appealing to travelers who are in the region during this period, when temperatures aboard Mekong river cruise ships can be 1 to 2°C (3 to 5°F) lower. This is because the Mekong’s waters flow from the icy Tibetan Plateau and the cool Laotian highlands, which takes the edge off the equatorial swelter and makie river cruising the ideal way to travel. The warmer months are also less humid.

In the meantime, the Aqua Mekong brings temperatures down further with state-of-the-art central cooling and an award-winning design that maximises ventilation. Grab an icy cocktail and take a dip in the plunge pool at the ship’s bow any time of day.

Rain-wise, rainfall in the lower Mekong basin peaks during August to October each year. Even during the wettest times of the year, rainfall comes in the form of brief showers typically lasting 30 minutes to an hour, thanks to Mekong’s inland position and savannah-like climate. So, travelers have it good: not only are itineraries and excursions unaffected by these brief showers, these showers also cool off the tropical countryside and bring sweet relief, usually in the afternoons when it’s most needed. After the afternoon showers, grey skies tend to disappear as quickly as they come, setting the stage for Mekong’s iconic multicolour sunsets.

With a mild annual monsoon lasting five to six months from May onwards, the brief showers also turn the already-beautiful Mekong countrysides into endless fields of vibrant green — a truly mesmerizing sight. Coinciding with the US and Europe summer holidays from June to August is Mekong’s picture-perfect ‘green season’, when the rice fields are at their most verdant.

In all, one of the plus points about the weather on the tropical Mekong is that there are compelling reasons to visit at any time of the year without having to worry about the weather.