Hoffman would have been pleased to be playing in the afternoon as he faced 15 mph winds, while those who started in the morning fared a lot worse as they had to battle against 40 mph winds.
Hoffman, who has eight top-10 finishes in nine appearances at the tournament, made a good start in his attempt to win the event for the first time after finishing second in 2011 and third in 2013.
The 38-year-old built his lead by nailing two birdies in his first three holes before going on to hit three more on the 9th, 11th and 17th hole.
Australia's Aaron Baddeley remains one shot behind Hoffman following his first round 68.
While he may not have the lead, Baddeley did hit the shot of the day on the par-four 17th. After hitting his tee shot into the trees, Baddeley decided to take a one-stroke penalty and re-tee his ball. It turned out to be a brilliant decision as he hit it straight and watched as the ball dropped into the hole to give him a birdie.
Max Homa is currently in third place on the leaderboard after his solid first round 69, which included six birdies.
Phil Mickelson, who has gone winless since the 2013 British Open, remains three shots behind Hoffman with his first round 70.
Despite losing the head of his 8-iron while playing his bunker shot on the 13th hole, the five-time major championship winner bounced back with three late birdies.
Meanwhile, 2010 US Open champion Graeme McDowell withdrew from the tournament after nine holes due to an ankle injury.