Washington’s beloved cherry trees signal the unofficial start of spring in the region. And it appears that for the third year in a row, spring will come early.

The National Park Service announced Thursday that the blossoms are expected to reach peak bloom between March 17 and March 20. The historical average peak bloom date is April 4, said Mike Litterst, a spokesman for the Park Service.

If conditions are optimal — mild temperatures and no high wind or heavy rain — the blossoms could stay on trees for a week to 10 days, Litterst said.

“They’re very fragile,” he said. “That’s one of the reasons they’re such an attraction. If they came out and they stayed on the trees for a month, it wouldn’t be nearly as big a deal.”

This weekend’s heavy winds might break some branches, Litterst said.

Peak bloom is the day on which 70 percent of the blossoms along the Tidal Basin are open. In 2016 and 2017, peak bloom was on March 25, according to National Park Service records.

This year’s National Cherry Blossom Festival will run from March 20 to April 15. To accommodate the predicted early peak bloom date, the Tidal Basin welcome area will open March 17, said Diana Mayhew, president of the festival. All other programming will take place as scheduled, she said.

Litterst added that visitors coming after the peak bloom date should still see blossoms because the District has more than a dozen types of cherry trees that bloom at different times. Peak bloom dates are calculated using Yoshino cherry trees, which are the city’s most dominant variety, making up more than 70 percent of all 3,700 cherry trees, Litterst said.

According to the Park Service, trees reached their green bud stage — the first of six stages leading to peak bloom — on Feb. 25.

Last year, peak bloom was pushed back after a cold snap, which killed nearly half the blossoms as they were beginning to emerge, Litterst said. However, if the region were to be hit with freezing temperatures now, he said, the blossoms would be protected because they are still in the bud stage.

Considered the world’s largest U.S.-Japanese celebration, the National Cherry Blossom Festival commemorates the 1912 gift of 3,000 cherry trees from Tokyo Mayor Yukio Ozaki to the District.

Takehiro Shimada, minister for Communications and Cultural Affairs at the Japanese Embassy in Washington, said he is excited that such a symbolic event has continued for more than 100 years.

“During even the bad times and the good times, the citizens of Washington, D.C., cherished these cherry trees as a symbol of the friendship between the United States and Japan,” Shimada said.

Given the festival’s long history, Mayhew said, the goal each year is to create events that ensure people will return. She said the festival is expected to draw an estimated 1.5 million visitors.

Additions to the lineup of events include the first Blossom Bash concert, scheduled April 6 at the Anthem, featuring alternative rock bands Third Eye Blind and Bush as well as Lovelytheband, an indie-pop group. Also new this year, tennis fans can participate in or watch the action at the National Cherry Blossom Festival Doubles Tennis Tournament on March 24-25 at the East Potomac Tennis Center in the District.

The festival’s signature events — the parade, kite festival and fireworks show — are also revamped every year with new performers and attractions, Mayhew said. This year, the Southwest Waterfront Fireworks Festival was renamed Petalpalooza and will feature live music, interactive art installations and fireworks. The free event will be held April 7 at the Wharf.

“It’s just a lot of fun and energy, and we want to actually invite people to get amped up for spring,” Mayhew said. “Beyond the blossoms, it’s the most important thing to celebrate, just continuing to celebrate spring in Washington.”