I’ve never actually been to Sri Lanka in the month of September, though I’ve been to Sri Lanka a number of times, and toured inland, and stayed on the SW coast at several different times of year.
September might well be a little wet on the SW coast, but rain tends to be in short bursts and it’s always warm rain!
If you aim to tour, then you may well find that inland you miss the rain, but again, I’ve had some wet days near Pinnawella elephant orphanage, and up near Kandy, when the travel guides say it should be dry.
Beware travel times in Sri Lanka – the SW coast resorts are typically 3 hours drive from the airport, longer if you arrive on Monday morning and hit the Colombo rush hour(s).
But Alutgama, Kalutara, Galle are all nice places I stayed at.
I don’t mind the long drive down, you see a lot of local colour.

Closer to the airport, you can choose to go slightly north to hotels in the Negombo area. Travel time around 45 minutes.

I haven’t yet tried the NE coast, in the area of Trincomalee which is apparently now opening up again to tourism since the war ended. But I really do want to go there.
You might find that side of the island is much drier in September.

To be honest, if you are happy travelling in Asia then I guess you will have experienced the sort of rainy times that happen now and again everywhere, throughout the year. And I reckon it’s not really a big problem. There’s always enough sunshine and UV to get a tan whenever one goes.

Sri Lanka is an amazing destination, as yet not ruined by tourism.
But it is changing fast now the war is over and with massive Chinese investment.
It’s probably good to go visit it soon before it gets really expensive and changes forever.

Thanks for the quick reply Bill

Hi puddleduck2

A few years ago we went to Sri Lanka in September. We stayed in Kalutara at the Royal Palms and did the touristy places - Pinewalla, Kandy, Dambulla, Sigiriya, Nuwara Elia.

The weather was excellent but the evenings can get cool in places like Nuwara Elia because of the altitude.

I understand that the West coast is by far the best option at this time of the year (September), although the sea may well be very choppy. Try to choose your hotel carefully to ensure that there is something to do in the evening.

We last visited Sri Lanka in March this year and the weather was certainly not as good as our previous September visit.

http://www.holidaytruths.co.uk/forum/kerala-and-sri-lanka-feb-mar-2012-t155183.html

Cheers

Peter

Thanks Peter that's very helpful