Jasper and Banff, September too late?

One more thought -- Kicking Horse Campground at Yoho is not that far from Lake Louise (half an hour) and is a lot quieter -- you can hear the trains a little at Yoho but not like at Lake Louise campground, which is unfortunately located right near a crossing, so the trains blast their horns night and day. Even with earplugs, we could not sleep at Lake Louise CG.

Kicking Horse at Yoho is right on the river -- very pleasant and well-located.

Best time to come up here is September. All the tourists and bus tours are gone. Plus it easy to find a campground. The Whistlers campground in Jasper is the best. Followed by Banff's Tunnel Mountain and Lake Louise. Tunnel is nice, not as private as Whistlers or Lake Louise. Lake Louise is more shaded than Tunnel but the trains rolling through at night are loud, unless you like trains. But do check with Parks Canada because some of the best places to camp (ie: Mosquito Creek) could be closed after Labour Day weekend which is a shame. Enjoy your trip and we will see you out there. Cheers!

September is a great time to visit Jasper as long as you aren't too used to a hot climate. We often find ourselves high up at Miette Hot Springs at thanksgiving in October. Usually there isn't any snow but last year we got a big snowfall the first night. It was lovely but also nice to go down the hill to summer again.

The previous posters are correct. Lovely time of year in the parks BUT do your research about campgrounds since many of the small campgrounds in Banff and Jasper parks will be closed, eliminating some lovely spots for camping. There will be a campground in Jasper, one in Lake Louise, and one in Banff still open and those three have powered sites for your space heater. You will be able to camp in those places and drive to see the other sights along the way. Don't forget to make a reservation to get up to Lake O'Hara for a walk in the fall colours. Contact Yoho National Park for more info.

And another nice bonus. The gazillions of Canadream &Cruise America's are gone until next year. :B
Art.

Tothill, that's a good point -- snow is not really a problem. A little snow can be a wonderful thing! At that time of year, it does not stick around very long, and the snow really brings out the unique texture of the Rockies -- this was taken in mid-September, the morning after a light dusting at Peter Lougheed Provincial Park, south of Banff:

September is beautiful in Banff.

We have had snow in June and September, but it did not stick around. There is something magical about sitting in the outdoor pool at the Banff Hot Springs and having snow land on your head.

There are full hook-ups available at Tunnel Mountain in Banff, so you can run a space heater if needed.

We have walked to the back of Lake Louise and up to the Tea Hut each month from May through September.

You will want to be prepared with 4 season clothing. Toques, gloves, warm waterproof jackets for hikes. The weather can change quickly in the mountains.

We were there through much of September last year -- probably the best trip we ever took, and that is coming from someone who has done a lot of camping and traveling. I think we got lucky on the weather -- hardly any rain, hardly any snow, cool days, cooler nights. Plus the crowds thin out after Labor Day!! And the larches were in full color at the higher elevations -- this shot was taken on Sept. 20, 2012, above Larch Valley near Lake Louise:

I'm not sure what you mean by snowed in. You might get snow & if you do just stay put for a day or two. It will quickly melt or be removed from the roads. The roads Harvard mentioned including the Icefield Parkway are year round roads. A severe snow storm would be rare in Sept and probably confined to one or two higher passes.
Sept can often be a beautiful time to be in the parks. Less bugs, less tourists, more scenic with snow on the peaks
Fall colours are more confined to the shrubery than trees but can often be very pretty when seen on an open slope. An exception is the Larch trees found at higher elevations and best seen above Lake Louise or in the Kananaskis.
Some nights will have frost but nothing to cause damage to a 3 seasson unit. Disconnect your water hose on the colder nights.
Keep in mind that the elevations in this area are lower than the Colorado area and this offsets some of the differences caused by being further North.
Sometimes Sept can be cool & wet but this can happen anytime. I say give it a try.

We live 45 miles NE of Banff Townsite as the crow flies. September is not known as a month of significant snow in the mountains and rarely where we are located (east of the Rockies). BUT being in the depth of the Rockies the Banff Jasper highway anything is possible. There are 3 bail out paths if it were to turn nasty. First Banff/Lake Louise to Calgary is very rarely a problem at any time let alone in September. Then you have Hgy 11 from the Saskatchewan Landing to Rocky Mountain House. Thirdly, you have Jasper to Edmonton.

BUT, you can count on cold nights in September. Even now in July Rocky Mountain House and Nordegg temperatures are getting down to 35F at night. This is a bit unusual and is making for a cooler then normal July.