Best Time to Fly: Hanoi → Phnom Penh

The honest answer to when you should fly Hanoi to Phnom Penh is mostly about weather and demand at the far end. On three years of daily observations at the arrival airport, Jan-Mar, Dec gives the most comfortable combination of temperature and rainfall in Phnom Penh.

Weather in Phnom Penh, month by month

Averages below come from three full years of daily readings at Phnom Penh’s main airport, not from a seasonal generalisation. The warmest month is April (average high 36°C), the coolest is January (average low 22°C), and the wettest is October (369 mm).

Climate data: Open-Meteo reanalysis archive.

Time difference and jet lag

Phnom Penh keeps the same clock time as Hanoi, so there is no adjustment to plan for and the date you choose is purely about weather and price.

When fares move on this route

We publish observed fares for this route when we have them, and say nothing when we do not — there is no estimate on this page. What holds regardless of the route:

• The travel date matters more than the booking date. Midweek departures are consistently cheaper than Friday and Sunday, because that is when demand actually sits.
• Comfortable weather and low fares rarely coincide. Jan-Mar, Dec is the pleasant window in Phnom Penh, which is also when more people want to go. The shoulder weeks either side of it are usually the better value.
• School holidays and local events override everything. A festival or a public holiday at either end will outweigh any general booking rule.
• Set an alert rather than watching manually. Fares move at hours you are not looking, and the useful booking window is weeks wide, not days.

Which day to fly

Midweek departures are consistently cheaper than Friday and Sunday on most routes, because that is where demand sits rather than because of any pricing trick. Where we have observed fares for Hanoi–Phnom Penh, the weekday breakdown appears further down this page; where we do not, we leave it out rather than estimate it.