Saigon has two seasons. The wet season, that starts in May and ends in November; and the dry season, that starts in December and ends in April.
The best season to visit Saigon is during the dry season. Specially in May, September and October, when it rains less. During the rainy season, it does not rain all day long. Rains are mostly strong showers that last a few minutes (sometimes a few hours). Rains refresh and clean the air.
During the Dry season the city of Saigon is hotter, more humid and its air dirtier. Not recommended. But do not despair if you are coming to Vietnam from March to May, because somewhere else in this diverse country will be the perfect time to go.
♥ Visit Tagulandang Island ♥