Solo female in Asia in September — Taiwan vs Vietnam before exchange in China?

I (f22) am going on exchange in China in September and want to spend around 5 days somewhere else in Asia beforehand after a week in Singapore. I’ve traveled solo quite a bit before, but I’m trying to choose a destination that feels manageable before moving to China for several months.

Right now I’m mainly considering Taiwan (probably Taipei + nearby areas) or Vietnam (Hanoi or Da Nang). I actually went to Vietnam solo last year and ended up leaving early because I got overwhelmed by the intensity of it all, but I think I’d handle it much better now knowing what to expect.

My biggest concern is honestly the September weather. From what I’ve researched:
Vietnam seems cheaper and more adventurous, but potentially very rainy depending on the region

Taiwan seems easier to navigate and maybe a softer cultural transition before China, but I’m worried about typhoon season/weather there too

For people who’ve been to either in September:

How bad is the rain realistically?

Which place did you find easier/more enjoyable solo?

If you had 5 days before moving to China, which would you pick and why?

I’d especially love hearing from other solo female travelers.