From April to November is the rainy season. South Vietnam is especially prone to flooding during this time. During the dry season, November to March, the temperatures are significantly cooler in North Vietnam. Some visitors like visiting during the tail end of the rainy season because of the lushness that results from the torrential downpours. While rainy, this is also a busy time for harvesting and fishing, and can be a good time to visit to see villagers at their busiest.
It can get quite cold in the mountains of Vietnam from December to February, but this is also when you’ll encounter the least amounts of tourists. This can be a more peaceful time to explore villages and meet locals around Sapa and Mount Fansipan. If you’re interested in photography, however, you should visit between August and September, when the fields turn from a rich green to bright gold.
The lunar New Year, or “Tet,” is Vietnam’s biggest national holiday. It takes place sometime around February, although the exact date changes every year. You may want to see some part of this celebration, but it’s generally considered a less ideal time to visit, as this is when many Vietnamese families choose to travel and more businesses are likely to be closed. Read more about Vietnamese holidays in our Holiday and Festival Travel Guide.
Following the New Year, it’s considered an auspicious time to travel to religious sites. Visitors should keep in mind that this is when temples and religious sites tend to be the busiest. Again, this isn’t a reason not to go—you might be interested to see a busy pilgrimage site—but it’s something to keep in mind if you prefer having the place yourself.