I was in Vietnam in July a couple years ago. It hardly rained when I was in Hanoi or on the trip south to Saigon, which lasted a couple days. When I did get to Saigon, it rained intermittently. The rain was always light and only lasted a couple minutes. So it’s not like you’ll be lambasted by the rain; I was still able to get around without becoming too wet. I hope this helps!

Yes, there were a few major downpours there, and September in Thailand was even wetter. “Still comfi”…. no… it’s not that it gets cold, it’s just that it’s hard to walk in your sandals, and your shirt becomes transparent, and you’re just really really wet! But then so is most everyone else.

If I were to spend another whole season there, and I was working and had things to do, I’d get a rain suit (slicker + pants) like you see motorcyclists wear. But for just a short time, hey, enjoy the spectacle!

In Saigon and the Mekong area July and August are really hot and humid. You get 30-35 degrees © during the day, with 80-100% of humidity. It rains every couple of days, torrential downpours which last a few minutes. You may get wet, but getting wet at 30 degrees is not that bad. Light rain gear is sold everywhere.

The only place where you may be cold is Dalat, which is in the mountains and has a temperate climate. You may need a sweater at night, shoes in place of sandals,and more serious rain gear.

In Nah Trang July-August is the dry season instead, and the sea is crystal blue (good snorkeling).

Going north, the rain can become a problem in the Hoi An / Hue area, with minor floods slowing down some trains, but not a big deal.

Hanoi and Halong Bay are steaming hot as Saigon (maybe even more), while Sapa, being in the mountains. can be as cold as Dalat.

Enjoy your trip!