Do We Need Raincoats or Ponchos?Raincoats or ponchos are probably not necessary. It's the dry season in Thailand and, on the off chance it does rain, it's usually brief and light. Most of the time you can see the rain coming and you can find an tree or a porch to duck under.
I don’t want to jinx the TdeT, but in the last 4 years we have only had 3 days total where it rained while riding.
Pack light, you will be happy you have room to take stuff home and not want to carry too much. Since we have support vehicles and Thailand is so easy going, try to adapt the easy going attitude and don’t over prepare. If we get lucky enough to have some rain it will be very refreshing while riding and likely stop within an hour or two.