He stumbled as a youngster and endured painful childhood nights in corrective shoes before finding his stride and becoming a state long-jump and high-jump champion.

After high school, Weems attended junior college at the University of Arkansas-Fort Smith, and was named 3rd team All-American, as well as all-conference and all-region as a freshman.

In two seasons at UAFS, Weems led the team to a 62–7 record and back-to-back Bi-State Conference Eastern Division titles.

Weems played his senior season with a new head coach, John Pelphrey, and was named first team All-SEC after averaging 15.0 points, 4.5 rebounds and 2.6 assists per game.

[6] After his team lost in the second round of the NCAA tournament, Weems later won the State Farm College Slam Dunk Championship held at the Final Four.

[8] Instead, Weems worked out with several teams: the Memphis Grizzlies, Orlando Magic, Chicago Bulls, Boston Celtics, Golden State Warriors, New Jersey Nets, New Orleans Hornets, and Portland Trail Blazers, receiving increased interest because of his high scores in speed and agility drills.

[10][11] On December 10, 2008, the Nuggets, for whom he had yet to play because of a surgery for sports hernia and then a groin strain, assigned Weems to their NBA Development League affiliate the Colorado 14ers.

[14] Weems scored 4 points in his NBA regular season debut with the Nuggets on January 17, 2009, when he substituted for Anthony Carter with 3:31 remaining in a 106–88 loss to Orlando.

[22] On August 18, 2009, Weems was traded by the Bucks to the Toronto Raptors along with Amir Johnson in exchange for Carlos Delfino and Roko Ukić.

[32] In his first season with the team, in a roster loaded with big European names like Miloš Teodosić, Nenad Krstić, Theo Papaloukas and Victor Khryapa, CSKA Moscow won 3rd place in the EuroLeague Final Four, after a 69–52 loss to Olympiacos in the semi-final game.

[36] Later in the season, CSKA won its third consecutive VTB United League championship by defeating Nizhny Novgorod, 3–0, in the final series.

[44][45] He made his debut for the Suns in the team's season opener against the Dallas Mavericks on October 28, recording 3 rebounds, 2 assists and 1 steal in a 111–95 loss.

[49] Weems struggled during his time with the 76ers, and after straining his right quadriceps on March 26 against the Portland Trail Blazers,[50] he was waived by the team the next day.

[57] With Guangdong, he won three consecutive CBA titles from 2019 to 2021, and was named Finals MVP in 2020 after averaging 34.7 points in a 2–1 series against Liaoning Flying Leopards.

In January 2022, after the match between Liaoning Flying Leopards, Weems was involved in an altercation with Liaoning Flying Leopards player Han Dejun, which resulted in both players being ejected from the match, with Han being fined $31,440 and suspended for seven games, while Weems was fined $22,008 and suspended for five games.

He wanted the elderly population and low-income families to have priority in the mask distribution as his grandmother works in the nursing home.