So far this century, March has come in like a lamb and gone out like a lion.

Yet for decades, March releases always seemed to run up against an unofficial barrier at the box office. The last time the month’s films surpassed 9.5 percent of the year’s total box office was 1990. That was followed by 19 consecutive years without March reaching that threshold again.

Suddenly in this decade, the switch has flipped. March accounted for greater than 9.5 percent of the year’s box office during three of the past seven years: 2010, 2012, and 2016. And highly anticipated releases for March 2017 and 2018 appear more than likely to continue that trend for these next two years as well, potentially even setting new records for March box office.

How did this happen?

How March used to be

For decades, the unwritten rule in Hollywood was that highly anticipated movies should be released during just five months of the year: May, June, July, November, and December. There would still be March releases, of course, yet their primary purpose was to help tide audiences over between December and May.

Yet even the biggest hits among the March films weren’t so much highly anticipated as slow-and-steady accumulators: examples include 1984’s Police Academy, 1990’s Pretty Woman, 1992’s Basic Instinct, 1997’s Liar Liar, 1999’s Analyze This, and 2002’s Ice Age. (Even then, once Ice Age became a far larger hit than expected, three of its four more-anticipated sequels would be released in July, while Analyze This sequel Analyze That would be released in December.)

What changed from 2010 to 2015

After a 19-year hiatus, March films passed the double-digit threshold with a fitting 10 percent of the year’s grosses in 2010. The two big hits that month were Alice in Wonderland, which earned a wonderful sum of $334.1 million, and How to Train Your Dragon, which soared to $217.5 million.

Both family-aimed films were ones audiences actually wanted to see, during a year when both box office and attendance declined overall. It also helped March as a percentage of the year’s grosses that the summer and holiday movie seasons were somewhat lackluster at the box office. Even tentpoles like May’s Iron Man 2, November’s Harry Potter and the Deathly Hallows Part 1, and May’s Shrek Forever After earned less than their predecessor films.

2012 hit the mark again with March releases accounting for 10.2 percent of the year’s grosses. The massive smash was The Hunger Games, which earned $408 million and launched the single biggest new movie star of this decade in Jennifer Lawrence. Yet one film alone can’t do the trick: March 2012 releases The Lorax planted $214 million and 21 Jump Street leaped to $138.4 million.

March 2013 came just slightly shy of hitting the double-digit mark, making up 9 percent of the year’s grosses, but it was still a successful month at the box office. Oz the Great and Powerful conjured $234.9 million, as The Croods took in $187.1 million and G.I. Joe: Retaliation punched its way to $122.5 million.

March 2014 resulted in four $100 million pictures, with Divergent leading the way with $150.9 million, as the adaptation of the first installment of the best-selling dystopian young-adult book trilogy followed in the footsteps of The Hunger Games two years prior. March 2015 saw the live-action Cinderella dream up $201.1 million, along with Home taking in $177.3 million and Divergent sequel Insurgent powering its way to $130.1 million.

This past March

2016 had a powerhouse March that the industry hadn’t seen in decades, with the month’s releases comprising 9.7 percent of yearly box office. More importantly, it also set the likely template for Marches in years to come.

Batman v. Superman: Dawn of Justice would have been the quintessential summer blockbuster in any other year—previous Superman film Man of Steel had bowed in June while previous Batman title The Dark Knight Rises debuted in July. But faced with the most crowded summer superhero slate of all time—including Captain America: Civil War, X-Men: Apocalypse, and Suicide Squad—Warner Bros. decided to jump ahead of the competition to the tune of $330.3 million, an improvement on Man of Steel’s $291 million.

Meanwhile, Zootopia proved one of Disney’s most popular films in many years, earning a phenomenal $341.2 million. That was notably more than some of their other seemingly more anticipated animated releases such as the previous November’s Pixar release The Good Dinosaur and subsequent November’s Moana.

March 2017 and beyond

Going into the future, March 2017 will see the live-action Beauty and the Beast, Wolverine superhero sequel Logan, Power Rangers, Kong: Skull Island, and Ghost in the Shell. All five could earn at least $100 million, with the first two in particular likely to crack the $200 million mark if not more. March 2018 includes Steven Spielberg’s Ready Player One, Disney’s Wreck-It Ralph 2 after the original earned $189.4 million, and the Tomb Raider remake. (The 2001 Angelina Jolie original earned an inflation-adjusted $199.5 million).

Spielberg practically invented the summer and holiday blockbusters, with June 1975’s Jaws and November 1977’s Close Encounters of the Third Kind. Starting with Jaws, Spielberg directed 26 consecutive films that were released in May, June, July, November, or December—the aforementioned lucrative summer and holiday movie seasons. He was the undisputed king of those months. Then 2015’s Bridge of Spies was released in October and his upcoming Ready Player One will launch in March 2018.

It’s not just the weather that warms up in March. These days, it’s the box office too.