A handful of players had gotten through only the second hole after taking off at eye-wateringly early tee times when organisers suspended play at 7:05 a.m. ET at the venerated course in Southampton, New York.
The event kicked off as a line of standstill traffic held up ticketholders in the fashionable beach town, with American Scottie Scheffler eyeing history, on the hunt for a career Grand Slam.
The 156-player field this week includes 12 former US Open champions and 49 debutants.
The US Open is known as the toughest test in golf, and the par-70 layout at Shinnecock Hills, which is hosting the event for a sixth time, is expected to uphold that reputation this week.
When Shinnecock Hills last hosted the US Open in 2018, the field scoring was 74.65, which is the highest scoring average relative to par for the tournament over the last 18 years.