Visiting Glacier, Yellowstone and Grand Teton Ntl Pk,s

All excellent responses to your question. Another recommendation to go in September versus May/June. Out here in the Rockies, we also have mud season, which corresponds with May/June and in to July depending on elevation. Mud season is that time when the snow is melting, sometimes rapidly, and there is mud everywhere. This is particularly true of NP/USFS campgrounds, where there will be snow on the ground in May/June. Commercial CG/RV parks cope with it better, so it won't be as bad in those locales. Tracking in mud inside one's trailer/RV can be a chore, so leave shoes/boots somewhere outside, easily accessible. Mud season will also cause many trails/hikes to not really be doable, much less pleasant. September will be more pleasant, as the trails/CGs have had all summer to dry out. Yes, September can see snow, but early in the season it is frequently light and fluffy vs heavy and wet. And it usually melts quickly in early September.

Wife and I will be visiting during tht time as well.

At least 5 days. Two weeks is better.

plkitchen wrote:
A lot of responses mention the crowds. Does anyone have an opinion on whether spring or fall is best to avoid crowds.

Two Totally different times of the Year - Spring is cold and Damp more than it is Sunny and Warm (JMHO) - more small animals - need good "WaterProof Boots" in the Spring. Spring snows are usually wet and Heavy - often Deep.

If you are planning the trip IMHO the Spring is the more unstable of the two seasons - May vs September - September is just better even with more People - Beartooth will likely be closed in the Spring, and we love the Beartooth Drive - mud will be more Prevalent - Spring is just a better time to be in Utah.

There is less to see and do in the spring - BUT - there is so much to see and do you still cannot go wrong if that were the choice made.

If It were Me - Fall even with a few more People - do your Homework - plan your Itinerary - and with just a little work you can find the peace and solitude you are looking for - you might even enjoy a few of the people you meet. - :S

Example On a trip in Colorado with the East Coast Grands - Flew them out to do Trail Ridge in RMNP for Memorial Day - Snowed over 3' a few days before and the top of Trail Ridge had 12' of Snow and was closed - Images - so busted on the big Plan - BUT - we drove up through Nederland to Red Rock Lake for a hike - In the Snow - In the Sun - cold but Warm - yes it is true in Colorado :) - the girls had as much fun as ever - they were with their Cousins.

We got great pictures and we will never forget the trip - neither will they.

So moral of the story - No Wrong Choices - except to not just DO IT!

More often than not it is the Trip more than the Destination,

JMHO

I would go the first or second week in Sept. In 2013 we went the last week in May and there was 6 feet of snow everywhere.

A lot of responses mention the crouds. Does anyone have an opinion on whether spring or fall is best to avoid crouds.

one_strange_texan wrote:

Busskipper wrote:

Yellowstone will not only be crowded but by September you might catch some snow - might get lucky and have 70's everyday, but plan for Cold and Damp and be Happy with Sunny and Warm.

We are also planning a trip to Tetons, Yellowstone, and Glacier in the same time frame in 2020.

I know snow is a possibility, but I am surprised Yellowstone is still crowded in September. I know it is very popular park, but I would think the crowds would be down some from the summer peak due to school being back in session.

Best trip we have ever had to the Park was in Late October - Early November - Indian Summer with not so many People.

Crowds are relative to where you are from and what you might prefer - that said - IMHO it is still Very Crowded in September!:S

Snow will almost always come in September - actually think it has snowed every month of the year in Yellowstone - BUT - it will Melt and IMHO just makes it even more Beautiful - Note here is to be Prepared for Any and Everything as you travel - Good Boots - Layers - Floppy Hat - Rain Gear - CAMERA that you will carry! (Take three pictures every time you think one will do)

Most important thing, might be to be Flexible in your Schedule, as the Weather and Your Interests will change. I use DOT webcams to help with the actual weather and the Yellowstone WebCams to see what is actually going on, IMHO these are the best!

Yellowstone NP WebCams

Last little note - there are things all around the Park to Enjoy - so if you have the time being a little flexible is not all that hard - Being Lucky has a lot to do with being Persistent, and being Smart, so while we still seldom make reservations we still enjoy most of these Beautiful National Parks - we just need to be a little smarter today than yesterday. - :)

Hope this helps,

Crowds are indeed lower in Yellowstone during September as well as early June. That is to say they drop from elbow to elbow during July and August to only feet apart. Think your nearest big city traffic between rush hour and 3 pm.

We were in Glacier, Yellowstone and The Grand Tetons in 2019 at about the same time. Everything is busy, parking is limited, everyplace is crowded. You either have to deal with it or not go. We had a great time even with the crowds.
Be careful about the weather. On about Sept 12 we went over the Bear Tooth Highway. We started early to see the Lamar Valley. By the time we left the Top Of the World store near the summit of the Bear Tooth, it was snowing hard, the road was covered by snow and they closed the road about 15 minutes behind us. We made it through without a problem but had to take a 150 mile detour to get back. Weather can be a beast that time of year. Still one our best trips ever.

So what do you like? Hikes, views, animals, camping style, travel style, personal goals, shopping, art, history, science, privacy, meeting people...

Specifics in questions will get you specific answers. There is no 'best'