Weather in mid-September...

[Pops921]

+1 for mid September Colorado weather.

The warm hat and gloves are a good suggestion - the gloves can be light weight. I always carry rain proof shell pants-which can also work as an insulating layer. I think you should carry a second insulating layer for the upper body which you will primarily use while stopped and enjoying the summit - I prefer a down sweater, but you can also carry a lightly insulated "Soft Shell" which offers wind protection and is water resistant (not waterproof), but is more breathable then Gore-Tex or E-Vent.

[rtittsworth]

I'm going on year 5 of our annual 14er Fest. In the past 4 years we have gone as early as the second week of September and as late as the 1st weekend of October. Last year was the first time we didn't have clear, blue skies and perfect weather the full 5 days. Got dumped on while hiking Huron. It's my favorite time to be in Colorado due to the cooler temps and the aspen trees changing.

As for micro spikes, I always pack them but have only had to use them once, last year.

[Broken Knee]

Agreed, bring along a range of layers and gear, then look at the weather and leave behind what you can.