How wet do you want to get? Monteverde typically gets more than 15" of rain in September. See the rainfall guide at costa-rica-guide.com/Weather/WeatherMap.html. Keep in mind that Monteverde is at a higher elevation and can be cool when it's not raining. Also roads to Monteverde are not paved and in rainy weather can be trickier than normal. On the other hand you could get lucky and have beautiful days if you are only going for 2-3 days and you won't have to deal with crowds as it's the height of off-season.
-:- Message from TripAdvisor staff -:-
This topic has been closed to new posts due to inactivity. We hope you'll join the conversation by posting to an open topic or starting a new one.
To review the TripAdvisor Forums Posting Guidelines, please follow this link: http://www.tripadvisor.com/pages/forums_posting_guidelines.html
We remove posts that do not follow our posting guidelines, and we reserve the right to remove any post for any reason.