Rainy Season : (early June to end of October). Average temperature 25.5C. The wettest month is September, sorry

have stayed twice at the Landmark and am going back- I can't see past that hotel Great hotel in a great location.
As for the time of year- yes unfortunately you are not going at a good time. However, there is every chance that you will get a fair amount of sun inbetween showers!
The city part of it won't be effected by the weather-believe me we have been out and about in a mini typhoon

My wife and I stayed at Amari Coral Beach in January of this year and loved the place. The staff were among the nicest I've ever encountered in any hotel, and you could tell it wasn't simply an act put on to enhance the chance of tips.

It's also very tranquil there, being situated just on the edge of town. However, you can get a tuk tuk into town for a few baht, giving you the best of both worlds.

I'm sure you will love the Landmark... make sure they know you are on your honeymoon and they will make you feel very special. There are some room pictures I posted on the photo album

and here are the photos

Sorry... didn't realise I had been so stingy .... so I've added a couple more.