Sen. Dianne Feinstein Celebrates Seersucker Thursday at Comey Hearing

Senator Dianne Feinstein - Comey Investigation - Screenshot - H 2017

Twitter took notice of the senator's summertime style too.

On June 8, all eyes were on former FBI director James Comey as he testified before the Senate intelligence committee in one of the most anticipated congressional hearings in recent history. The day also marked another important event in D.C.: National Seersucker Day (also known as Seersucker Thursday).

The annual tradition is celebrated by senators in the U.S. Congress, who wear clothing made of seersucker, the light, cotton-based fabric that's associated with summertime attire. California Democratic senator Dianne Feinstein kept the tradition alive during Comey's hearing, sporting a blue seersucker suit.

Twitter took notice of her summertime-ready look too.

The tradition started in the 1990s with Mississippi Sen. Trent Lott, who wanted to show that "the Senate isn't just a bunch of dour folks wearing dark suits and — in the case of men — red or blue ties," according to the U.S. Senate's website. (And really, you can't make this up.)

In 2004, Feinstein encouraged women in the Senate to take part in the annual event too. She said, "I would watch the men preening in the Senate, and I figured we should give them a little bit of a horse race." (Go girl!)

Seersucker Thursday was discontinued in 2012 but returned in 2015 thanks to Louisiana Sen. Bill Cassidy, who said at the time, "Louisiana is proud to have played an important part in introducing the country to seersucker apparel. The first seersucker suit was designed by Joseph Haspel at his Broad Street facility in New Orleans. This lightweight cotton fabric, known for its signature pucker, has been enjoyed by Americans from all walks of life during our hot summer months."