I'm thinking of going to Banff for about 3 days (not including travel days), around late Aug or early Sept. The weekend that works out best unfortunately happens to be Labor Day weekend. If I can shift the schedule a few days, would it be better to go before or immediately after Labor Day? I'm hoping for good weather (no rain, not too chilly) but from my initial research, it looks like early Sept can sometimes start to get chilly, especially in the higher elevations, so I don't want to push the dates out too far. Would the days immediately after Labor Day still be pretty crowded?

Your odds will be a little bit better after Labour Day and prices should be a bit better, too. You see, us Canucks are desperate to squeeze those last few days of warmth out of the summer in the mountains and, as you have noticed, it cane either be a bit dicey once September rolls around. You could get 80 degrees, or you could get 50 degrees, for a high temperature. I would bank on low 70's or high 60's if you made it there before the middle of the month.

It's not going to make much of a difference.

Pricing will be the same before or after Labour Day -- accommodations don't tend to lower their prices to off season rates until after our Thanksgiving (early October). You also won't likely notice much of a drop in crowds, though as Canadian (and US) kids head back to school, the composition of the crowds change from a mix to more foreign tourists. Lake Louise and Moraine Lake can be VERY busy on September weekends because of 'larch fever'.

A few days or even a week isn't going to make an appreciable different in terms of temperatures. We can get snow any month of the year, and have had dumps on Labour Day weekend more than once in recent years. Certainly the weather can get less stable as you get farther into September, but as mentioned on any of those days, you can get a huge variety of temperatures. All in one day.

Your best bet is to look into accommodations and see what is available and when.

Thanks for the replies. kgsneds - I didn't know about the larch season, so that's helpful to know. I'm trying to use some frequent flier miles, so that combined with what hotel availability there is will influence things. Otherwise I may need to re-think dates.