I've done that run across the city to Ekkamai a few times and it certainly can get wet!
I'd often get the bus from Pattaya to there then head off to other special places in Bangkok like Bayoke Tower to buy 500 printed polo shirts for shipping to one of my projects, a sort of uniform present to my Indonesian workforce in the Yemen or other clothing to be baled and exported. Then I'd head over to Soi NaNa for a couple of beers with a pal, or to the Emirates building to change a flight ticket, eventually rushing back to Ekkamai for the bus back to Pattaya.
Despite the rain, I'd still go back there to live if I could, it's far more exciting than living through the failing, backward looking UK since Brexit.