Votes received from national governing body representatives and select members of the media account for 50 per cent of the final tally, with the other half determined by online fan voting until midnight tonight.

Gymnastics, ice hockey, cycling, swimming, softball and surfing are represented among the 13 finalists across men's, women's and team categories.

The male athlete of the month category comprises Para-swimmer Robert Griswold, gymnast Sam Mikulak, swimmers Ryan Murphy and Jordan Wilimovsky and Para-cyclist Oz Sanchez.

Griswold set three Pan American and five American records at the Pan Pacific Para Swimming Championships in Cairns and finished with four gold medals and one silver.

Mikulak became the first US man in 18 years to claim five all-around national titles after winning at the US Gymnastics Championships, where he also earned the floor exercise, parallel bars and high bars titles.

Murphy matched the third-fastest effort in swimming history in the 100 metres backstroke to sweep gold in the 100 and 200 back at the Pan Pacific Swimming Championships, and added a third gold medal in the men's 400m medley relay - earning the Male Swimmer of the Championships honour.

Wilimovsky won gold in the 1,500m freestyle and open water 10-kilometres event, plus silver in the 800m freestyle, which was the top individual medal performance among American men at the Pan Pacific Swimming Championships.

Sanchez earned his first individual world title since 2011 and added another team gold and individual silver medal at the UCI Para-Cycling Road World Championships.

Contenders for female athlete of the month are gymnast Simone Biles, surfer Courtney Conlogue, swimmer Katie Ledecky, Para-swimmer Becca Myers and Para-cyclist Jill Walsh.

Twenty-one year old Biles, a quadruple gold medallist at the Rio 2016 Olympics, became the first woman to win five all-around titles in USA Gymnastics' history after winning at the US Championships.

Conlogue overcame a serious foot injury to defeat the top two surfers in the world and become the US Open champion.

Ledecky led Team USA women at the Pan Pacific Swimming Championships with five medals, including repeat gold-medal performances in the 400m, 800m and 1,500m freestyle events, as well as one silver and one bronze.

Myers set one world, two Pan American and four American records at the Pan Pacific Para Swimming Championships and finished the meeting with five gold medals.

Walsh finished the season ranked number one in the Para-cycling rankings after claiming two world titles - her first world crowns since 2015 - at the UCI Para-cycling Road World Championships.

There are three on the shortlist for team of the month.

The US under-22 women's select ice hockey team completed a three-game sweep during the under-22 series against Canada.

The US men's hand-cycling relay team won world Para-cycling gold after a finish line win over Italy by Will Groulx, David Randall and Sanchez at the World Championships.

The US women's softball team qualified for the Tokyo 2020 Olympics after finishing with a perfect record and claiming the gold medal at the Women's World Championship.