I am going to Thailand in November and I was wondering if it was still too early to book my internal flights?

I need to buy tickets from Bangkok to Chiang Mai and right now Air Asia and Bangkok Airways are about the same price. I also need to buy tickets from Chiang Mai to Singapore and from Phuket to Bangkok.

Thanks!

It's never too early. But is your purpose to save money or some other worry?
I've purchased tickets in-person at the counter a few hours before the plane departed. Also no problems.

The only problem with buying them so early for your (I'm assuming) vacation, is that you are then pretty much locked into your plans. I usually buy my tickets when I'm over there...either online or with a travel agent. I might not get the best deal for booking a few days in advance, but the convenience factor makes up for it.

If you save 500 baht per flight by booking online, and you have 4 internal flights, that's saving/wasting 2000 baht total. 2000B / 30USD = $66 USD. In the grand scheme of the whole vacation, that's not much money.

Are you worried about the flights selling out or being cancelled? I've only ever experienced that once, and that was because the airline cancelled service to the city alltogether. They rebooked me on the other airline and my departure was moved back a few hours.

Air Asia won't get any cheaper and it's unlikely PG would. Keep tabs on the flights to/from CNX, especially if you're looking to travel around Loi Krathong.