Guess it depends where you are/were - I'm across from Sathorn Pier and it rained for about 20 minutes at 10ish this am - but not nearly as bad as the time it was a rain "white out" (can't remember exactly when that was) I guess I was lucky as traffic seemed lighter than normal on my excursions to Chinatown, Paragon and back (around noon and back at 4ish) - but you are right - the horrible traffic gets much worse with rain and what I saw was clearly different than it was in other areas.
Originally Posted by
transpac
If you arrived today (Wednesday, 24 Jan), after 10 AM, we got easily the heaviest rain I've ever seen here, even in monsoon season. Once this happens traffic is messed up everywhere for the entire day. At 16:30 I'm getting traffic alerts with delays into the 100 minute range, and red nearly across the board on gmaps.
It's been an odd "dry" season this year. On the plus side it cleared up the horrible (again unseasonable) smog we've had over the past few days.
In my experience here over 15 years, it is best to agree to use of the meter, or a mutually agreed upon flat rate, and any preferred routing BEFORE entering a taxi.