It's a very outdoorsy venue with almost entirely grass under your feet so ditch the stilletos! Otherwise semi-formal to Garden attire is fine, no black ties required.
It will generally be hot in July in Boulder but it's a very dry climate. Colorado is famous for it's changing weather - the expression here is "If you don't like the weather, wait an hour!" There are commonly breif, light thunder showers in the afternoons in the summer, they'll come and go in about an hour anywhere from 2-4pm. Layers are key! Especially if you plan to visit some of our higher elevation locations where it is cooler.
Yes, there is some parking at the venue but we would strongly encourage carpooling or taking an Uber or Lyft, especially if you plan on having some drinks. The venue is right in town, east Boulder, so an Uber/Lyft ride is affordable, easy and safe!