I'm going to be in Koh Phangan for 10 days in the middle of May and wondered what the weather will be like

thanks for any help.

Most likely hot and sunny with afternoon thundershowers, or evening thunder showers. And by thunder, I do mean thunder! and lightning. They blow right through, coming from the southeast, so you might consider staying on the west or northern side of the island.

cheers we're staying south, already booked. Is it lenghty rain and thunder or are they quite quick showers? I was looking forward to some sun!

Blows quickly through. You might get a day or two of rain but it is unlikely.

Generally, by May the Pattaya wind has started (don't ask me why it is called the Pattaya wind when it comes out of the southeast) and that means rapidly moving storm fronts that will literally blow through in an hour or two.

At night there can be lightning and thunder, you'll see it mostly behind Samui and towards the Surat Thani mainland. Be prepared for some spectacular lightning shows and be sure to unplug any gadgets before going to bed!

The storms sound spectacular! Thanks again for the info. I can't wait to get out there, hopefully for some sun and by the sounds of it some amazing light shows, should be entertaining!