According to Ken Rubin, an assistant professor of geology and geophysics at the University of Hawaii, "It snows here every year, but only at the very summits of our three tallest volcanoes (Mauna Loa, Mauna Kea and Haleakala).
"The snow level almost never gets below 9,000 feet in Hawaii during the winter, but since these mountains are taller than 13,600 feet, 13,700 feet and 10,000 feet, respectively, they get dusted with snow a few times a year," he added. "It rarely stays on the ground for more than a few days though."
In fact, it even snowed atop the summits in late July 2015.
Technically, it is possible to ski in Hawaii, but there are a lot of caveats.
Mauna Kea Ski Corporation explains that "Mauna Kea is a National Science Reserve and is not maintained as a ski area. Skiing areas may have unmarked and exposed rocks. Adverse weather conditions may arise unexpectedly ... most runs are for intermediate to advanced skiers/snowboarders ... weather permitting."
In addition, the Hawaii Ski Club cautions potential skiers that "there are no lifts, no g***ming, no resort, but a road goes to the summit to serve the dozen or so world-class observatories located at the summit. You must have a 4-wheel drive vehicle to get to the summit, which serves as your 'lift.'" The club adds that skiers take turns being the driver, picking up the other skiers at the bottom of the runs and ferrying them up to the summit.
"Conditions at the top are extremely variable. Winter temperatures range from 25 to 40 degrees, but wind chill and the high altitude can make it seem much colder. Between April and November the weather is milder, with daytime temperatures varying from 30 to 60 degrees."
I have been to the summit of Mauna Loa, Mauna Kea and Haleakala during summer months and if you don't wear a warm jacket or coat you'll freeze your ass off.