Hi! My fiancé and I are trying to plan a honeymoon in September (our wedding is in August). We were looking at Costa Rica, but saw their rainy season started in September and extended into November. Does anyone know if September is rainy enough to ruin a lot of outside excursions and activities?

www.weather2travel.com climate guide CR quite rainy then.
When there last Aug-Sept last rained almost every day at noon several aguaceros(deluges). So I go to Cabo Mexico Capeela Pdregal or Mauna Kea on the Big Island stayhawaii.com konaweb.com 1 inch of rain per month on the Kohala Coast a wonderful place. Actually Hapuna Prince for me last good hotel car air package 4 hours to Kona was $1k pp very romantic and adventurous. Volcanoes NP is amazing there.

Congrats!

I love Priceline.com: Hapuna Prince for $105/night! Hawaii
www.flyertalk.com/forum/archive/t-911579.html
Great values on priceline.com here for me.

We've also visited Costa Rica during the rainy season; depending on where you are, it can be nil to just a brief shower during the day (up in the northwest, Tamarindo), to all-day downpours (farther south); however, even though we were also in the Manual Antonio and Uvita areas during rainy season, we had days that were sunny.

Mouse over this map. It depends on which areas you want to visit.

http://costa-rica-guide.com/Weather/WeatherMap.html

The rainy season runs May to early December or so. September and October are the wettest months where it could rain 24/7 for days at a time. People still come to Costa Rica during those months. Most nature-type activities go on rain or shine, but if lazing on the beach is what you want to do, that could be a problem. Does it have to be Costa Rica?

wow, thanks everyone. It looks like we'll be looking for a differnt place to honeymoon, we don't want to take the chance. Any other recommendations other than Hawaii in August or September? My parents used to live in Hawaii so I've already been there a few times and want to go someplace where there's a lot of site seeing and where we can be active.

Belize is also amazing. I don't know what their weather patterns are, but you could do a little research and find out. They have awesome adventure activities and amazing snorkeling, ruins, etc. September is hurricane season, so that's always a consideration.

Last season down here Sept wan't too rainy but oct/nov ripped !
I'd say Sept is often the worse month for rain.
The best place to spend the month of Sept IMNSHO is a trip to Seattle to visit the rain forests there and then fairy over to Vancouver Island. It's a stunning place.

"fairy over"
Sorry, but that just gave me such a mental image...