Visit Laos at Mid September 2013?

I was in Laos in mid October 2011, still rainy season.

It did not affect my trip that much at all. A few rainy days. I didn't experience any chaotic flooding or anything like that. Downpours rarely last all day. When you are further north, the rain will affect you even less.

Stay longer than 6 days. Travel in Laos can take time. It is also a wonderful country with lots to see. 6 days is hardly enough time!

I spent a couplaweeks in Laos in Sept 2011, certainly many of the roads were closed off the main routes, but you are probably OK sticking to the major centres. But Thailand was inundated and the train from Nong Khai to BKK return was cancelled a couplatimes..

My experience is that the rain comes in two varieties. There is the daily late afternoon rain - a welcome respite from the heat. SLows down traffic for an hour on an unsealed road, but in general it will not affect your schedule.

Then there is the "6-day" rain, where it starts one week and stops the next. Big heavy drops are interspesed only with slightly smaller wet drops. Rivers overflow, roads are blocked, naked kids play soccer in the slime. Usually such weeks happen a couple times a season.

Whether you're there the week of the afternoon respite or the rarer flood-rains will have to be answered either after the fact or imagined in your prayers.