These world famous springs can be enjoyed from five outdoor pools of progressively high temperatures, rising from approximately 102 to 112 degrees. Some of the pools are rock-bottomed, others gravel; if you're visiting in winter, you will appreciate the heated sidewalks. Some of the pools are covered by large roofs, meaning they can be enjoyed irrespective of the weather: sun, rain or snow. Over 2.5 million gallons of water pass through the springs every day, keeping them naturally clean and fresh.
If you go:
The pools are open every day except Thanksgiving and Christmas Day. Hours are 8.00 am to 11.00 pm from May 1 - Sept 30; 9.00 am to 10.00 pm (11.00 pm Fri/Sat) from Oct 1 - April 30.
Links:

430 East Main
Lava Hot Springs, Idaho 83246 USA
info@lava.idaho.gov
Mailing address:
Lava Hot Springs State Foundation
P.O. Box 669
Lava Hot Springs, ID 83246 USA
Phone Numbers:
+1 (208) 776-5221
Toll-free
+1 (800) 423-8597
+1 (800) 423-8597