Williamson averaged 25.7 points, 6.2 rebounds and 2.6 assists while shooting 56.3% from the field in nine games.
Williamson, 19, made his NBA debut on Jan. 22 but didn't cross the 30-minute threshold in a game until Feb. 2. Williamson scored at least 20 points in every game in February and, dating back to Jan. 31, has scored at least 20 in 11 consecutive games, the most in NBA history for a teenager.
In an interview with ESPN's Eric Woodyard on Monday, Williamson said nothing has surprised him so far about his rookie season in part because of his support system.
"Nothing's really caught me off guard because my parents, especially my mom, she really prepared me for life in this world and how things are handled," Williamson said.
With Williamson back in the lineup, the Pelicans are making a push for the final spot in the Western Conference playoff race. New Orleans is 3½ games back of the Memphis Grizzlies for the final spot.
Williamson's win put an end to Memphis guard Ja Morant's streak of three consecutive Rookie of the Month awards to start the season.
Williamson is coming off his second matchup with LeBron James and the Los Angeles Lakers on Sunday, when he had a career-high 35 points in a loss. When asked after the game about setting the streak for most consecutive 20-point games as a teenager, Williamson looked toward the locker room for his answer.
"I thank my teammates and my coach for that," Williamson said on Sunday night. "They trust me and put me into positions to be me, so it's definitely an honor to be in that category."
Williamson became the fifth player in Pelicans franchise history to win a Rookie of the Month award, joining J.R. Smith (2004-05; three times), Chris Paul (2005-06; six times), Darren Collison (2009-10) and Buddy Hield (2016-17).
Chicago Bulls guard Coby White was named the Eastern Conference's Rookie of the Month after averaging 20.1 points, 4.1 assists and 4.0 rebounds per game while shooting 41.1% from deep. It was White's first honor of the season.