Re: Malaysia and Thailand
 

I am not sure where you are based Ex Reg but I suspect this must be a question of relativity - I am not trying to wind you up. To me Muscat is dry - 45 to 50 percent humidity. Singapore/Malaysia 80 to 90 percent humidity is, well, very humid. But see links below if you do not agree.

http://www.timeanddate.com/weather/oman/muscat

http://www.timeanddate.com/weather/singapore

Re: Malaysia and Thailand
 

Those figures appear to refer to Seeb which is about ooh dunno 30km north of Muscat.
Muscat because of its position is almost a micro climate and those figures mean zilch when comparing the humidity in Muscat itself.