The weather can change quite frequently throughout the day. Bring a light jacket for at night and sunglasses for the bright sun.
If you are coming in from out of town, you will want to drink lots of water before your travels and during. Hydration is important in high altitude.
Estes Park is 15-20 minutes away from Allenspark.
https://www.visitestespark.com/plan/about/faq/
A little over an hour