GW usually stays at a constant temp. throughout the year, and has a constant movement. So I would say Yes to the higher temp's., as compared to a lined runoff pond.

Almost every pond around here is a GW pond.

There is a shallow clay lined pond out back that a guy put in for watering deer next to his food plot. Totally Dry! so the deer come up to a GW watering hole my BIL put in. They can also go from this spot, maybe a half mile and get water.