National Center for Atmospheric Research, Boulder (always free)
The National Center for Atmospheric Research (NCAR) has created a beautiful nature preserve on their property on Table Mesa Drive in Boulder, at the base of the Flatirons.
In addition to great hiking along their "weather trail", there is a free visitor's center that you are welcome to explore on your own or with a tour guide. The center outlines Colorado's local weather systems as well as NCAR's research in the field of meteorology and atmospheric study.
Monday-Friday 8 to 5
Saturday, Sunday, and Holidays 9 to 4
1850 Table Mesa Dr.
Boulder, CO 80305
Just take Table Mesa road in Boulder west toward the Flatirons. As you enter NCAR property, the road will wind its way through the nature preserve and end up in the parking lot for the NCAR Visitor's Center.