After playing the last eight weeks in the heat and humidity, the cooler weather near the Pacific Ocean will be a drastic difference in Thursday's 2020 PGA Championship. Justin Thomas, coming off a St. Jude win that moved him to No. 1 in the world, and two-time defending champion Brooks Koepka are listed as 10-1 co-favorites in the latest 2020 PGA Championship odds at William Hill. Bryson DeChambeau (11-1), Rory McIlroy (14-1) and Jon Rahm (14-1) are among the other 2020 PGA Tour Championship stars that oddsmakers expect to challenge Koepka's pursuit of a third straight PGA title.

Tiger Woods is also in the 2020 PGA Championship field and comes in at 22-1 to win it all in only his second event since February. Before making any 2020 PGA Championship picks, you need to check out the latest PGA Tour predictions from SportsLine's resident golf insider, Sal Johnson

A media legend and consummate golf insider, Johnson predicted the PGA Championship last year, singling out Koepka in his best bets. Koepka built a seven-shot lead entering the weekend at Bethpage and rolled to his fourth major victory. "I really like him a lot this week," Johnson told SportsLine before that event. "He is playing well and this is a course he can attack and play well on."

The prediction was part of Johnson's banner 2019 season, when he featured Tiger Woods in his best bets for the Masters, and Woods walked away with his fifth green jacket. Johnson also completely nailed the season-ending Tour Championship. He predicted Koepka, Rory McIlroy or Xander Schauffele would win, and those were the top three finishers. Anyone who followed Johnson's golf picks saw huge returns.

His success has carried into this season, and before last week's WGC-St. Jude Invitational, Johnson tabbed Thomas in his best bets and also touted 100-1 long shot Phil Mickelson to contend for the title.

Thomas went five-under par Sunday to win by three strokes and take over the No. 1 spot, while Mickelson tied for second as he sought to become the first player over 50 to win a WGC event.     

Now, Johnson, the first producer of "Inside the PGA Tour," a longtime ABC Sports golf producer who has worked with Jack Nicklaus, Arnold Palmer and Greg Norman, and the founder of the world's top golf statistics database, has released his highly confident 2020 PGA Championship picks here, and they will surprise you.

Top 2020 PGA Championship expert picks

Johnson is fading DeChambeau, even though he's the third-biggest favorite at 11-1. The 26-year-old has finished in the top 10 in eight of his 13 events but missed the cut at the Memorial and tied for 30th last week. He shot 73 or worse in three of those six rounds, and the course and conditions at Harding Park don't set up well for his long game.

Johnson is locked in on the game of McIlroy, who was the best player on Tour before the break but has gotten out of rhythm. The Northern Irishman tied for 11th in the Travelers but finished well outside the top 25 in his other three events since the layoff. Still, he is fourth on tour in strokes gained off the tee and eighth in total strokes gained. He won the last big event at Harding Park, beating Gary Woodland in the 2015 WGC-Match Play Championship. 

Johnson has been locked in on Rahm since the 25-year-old turned pro in 2015. The Spaniard is second in the Official World Golf Ranking and has five top-10 finishes, including his victory at the Memorial. He tied for 52nd last week but fired a 65 in the final round and is seventh on tour in scoring average. He also is 28th in greens in regulation and 26th in strokes gained putting, both factors that will be critical this week with the conditions limiting distance at Harding Park.

How to make 2020 PGA Championship predictions

This week in San Francisco, Johnson is all over a monster long shot who comes in at odds higher than 50-1. This young golfer hasn't been strong at majors, but he has been hot and has the stats to play well at Harding Park. He could be primed for a major breakthrough, and anyone who backs this underdog could cash in huge. See who it is, and get all of Johnson's top PGA picks, right here.

Who wins the PGA Championship 2020? Where do McIlroy and Rahm finish? And which monster long shot is a must-back? Check out the odds below, then visit SportsLine to see Sal Johnson's full leaderboard, picks and analysis for the 2020 PGA Championship, all from the insider who has was all over Koepka's huge PGA Championship win in 2019. 

2020 PGA Championship odds (via William Hill)

Brooks Koepka 10-1
Justin Thomas 10-1
Bryson DeChambeau 11-1
Rory McIlroy 14-1
Jon Rahm 14-1
Dustin Johnson 22-1
Xander Schauffele 22-1
Tiger Woods 22-1
Patrick Cantlay 24-1
Webb Simpson 28-1
Collin Morikawa 35-1
Rickie Fowler 40-1
Hideki Matsuyama 40-1
Jason Day 40-1
Daniel Berger 40-1
Viktor Hovland 40-1
Tyrrell Hatton 45-1
Patrick Reed 45-1
Justin Rose 50-1
Jordan Spieth 50-1
Tony Finau 50-1
Tommy Fleetwood 50-1
Gary Woodland 50-1
Matthew Fitzpatrick 50-1
Adam Scott 50-1
Paul Casey 66-1
Sergio Garcia 66-1
Louis Oosthuizen 66-1
Marc Leishman 66-1
Matt Kuchar 66-1
Sung-Jae Im 66-1
Abraham Ancer 66-1
Shane Lowry 70-1
Matthew Wolff 80-1
Henrik Stenson 80-1
Brendon Todd 80-1
Phil Mickelson 80-1
Bubba Watson 100-1
Billy Horschel 100-1
Scottie Scheffler 100-1
Byeong Hun An 100-1
Joaquin Niemann 100-1
Adam Hadwin 100-1
Chez Reavie 100-1
Danny Willett 100-1
Max Homa 125-1
Kevin Kisner 125-1
Harris English 125-1
Kevin Streelman 125-1
Ian Poulter 125-1
Tom Lewis 125-1
Cameron Champ 125-1
Matt Wallace 125-1
Corey Conners 150-1
Emiliano Grillo 150-1
Kevin Na 150-1
Michael Thompson 150-1
Joel Dahmen 150-1
Bernd Wiesberger 150-1
Brendan Steele 150-1
Martin Kaymer 150-1
Rory Sabbatini 150-1
Erik van Rooyen 150-1
Christiaan Bezuidenhout 150-1
Brandt Snedeker 150-1
Charl Schwartzel 150-1
Lucas Glover 150-1
Ryan Moore 200-1
Hao-Tong Li 200-1
Danny Lee 200-1
Sepp Straka 200-1
Sung-Hoon Kang 200-1
Kurt Kitayama 200-1
Cameron Smith 200-1
Zach Johnson 200-1
Rafa Cabrera Bello 200-1
Dylan Frittelli 200-1
Scott Piercy 200-1
Matthias Schwab 200-1
Graeme McDowell 200-1
Cameron Tringale 200-1
Joost Luiten 200-1
Russell Henley 200-1
Troy Merritt 200-1
Mackenzie Hughes 200-1
Keegan Bradley 200-1
Brian Harman 200-1
Luke List 200-1
Si-Woo Kim 200-1
Jason Kokrak 200-1
Doc Redman 200-1
Robert MacIntyre 200-1
J.T. Poston 200-1
Ryan Palmer 200-1
Adam Long 200-1
Keith Mitchell 250-1
Jason Dufner 250-1
Wyndham Clark 250-1
Talor Gooch 250-1
Lanto Griffin 250-1
Nick Taylor 250-1
Andrew Putnam 250-1
Harold Varner 250-1
Jim Furyk 250-1
Matt Jones 300-1
C.T. Pan 300-1
Bud Cauley 300-1
Vaughn Taylor 300-1
Marcus Kinhult 300-1
Andrew Landry 300-1
Denny McCarthy 300-1
Jazz Janewattananond 3-1
Victor Perez 300-1
Sebastian Munoz 300-1
Joohyung Kim 300-1
Jimmy Walker 350-1
Carlos Ortiz 400-1
Tyler Duncan 400-1
Benjamin Hebert 400-1
Mike Lorenzo-Vera 400-1
Tom Hoge 400-1
Mark Hubbard 400-1
Jorge Campillo 400-1
Shaun Norris 500-1
Brian Stuard 500-1
Steve Stricker 500-1
Zach J. Johnson 500-1
Lucas Herbert 500-1
Ryo Ishikawa 500-1
Chan Kim 500-1
Nate Lashley 500-1
Davis Love 750-1
Jim Herman 750-1
Ken Tanigawa 1000-1
Rod Perry 1000-1
Rich Beem 1000-1
Shaun Micheel 1500-1
Alex Knoll 1500-1
Jeff Hart 1500-1
Rob Labritz 1500-1
Jason Caron 1500-1
Ryan Vermeer 1500-1
Justin Bertsch 1500-1
Shawn Warren 1500-1
Alex Beach 1500-1
Judd Gibb 2000-1
Michael Auterson 2000-1
Ben Cook 2000-1
Rich Berberian 2000-1
John O'Leary 2000-1
David Muttitt 2000-1
Danny Balin 2000-1
Jeff Roth 2000-1
Bob Sowards 2000-1
Marty Jertson 2000-1