Just wondering if anyone has suggestions of schools with involved and smart students that have good weather (doesn’t have t be 90 everyday, just mild winters and in general nice weather)? Im just looking for a broad list of schools and suggestions, nothing too specific!
I am not sure you could beat weather in San Diego or Tuscon. Unless you love humidity, then maybe south Florida.
Claremont Consortium colleges
Davidson.
They can also be large universities if anyone has any suggestions?
Both USCs, USD, UCLA, Texas A&M.
College of Charleston
UC Berkeley, Stanford, Mills College, University of Santa Clara, USF, Cal Poly SLO, Occidental. Depending on what you think of humidity - Rice, Trinity (San Antonio).
Great weather is in the eye of the beholder. My D2 wanted a school where there was snow (after living in Southern CA). If you want warm and no snow look at the southern part of the US. I assume you have a map. 
All the UC schools! Especially, UCLA, UC Santa Barbara, UC Davis, UC San Diego, and UC Irvine
UNC Wilmington. One of the most underrated colleges and one of the top beach schools in the country.
Your desire for “mild winters and in general nice weather” makes me think of Southern California, in particular San Diego.
Much of Texas has mild winters. Consider UT-Austin, Texas A&M, SMU, TCU and Rice (as already mentioned it’s much more humid in Houston).
Tulane is an excellent university. New Orleans has mild winters but it is prone to heavy rainfall.
You can always go on https://colleges.niche.com/ and read students’ reviews and perceptions of the weather. Each college is given a grade in different categories, including weather. It will even include weather averages for each season at the bottom of the weather page for some, but not all, of the colleges.