The 30-year-old striker spent the entire 2012/13 campaign with the Robins from Bury, helping Mark Yates' side reach the League Two play-offs.
He now arrives from League One Notts County with the club at the wrong end of the table, but he is confident the experience boss Russell Milton has brought in this week, along with real unity in the game will see the Robins stave off the drop.
"I am delighted to be back here and I want to do my best to help shoot us back up the league," Harrad said.
"Russ was the youth team coach when I was here before and he must have seen something in me that he thinks he needs now.
"He’s brought in a few new lads to help push us over the line and I am excited to be here."
After the conclusion of his last loan spell at Whaddon Road, Harrad turned out for Bury before joining Conference club Alfreton Town.
He joined Notts County in the summer of 2014, but has made only four starts in League One this term.
"I haven't played enough football and I can't wait to get going here on Saturday," he said.
"I have been in this position at Northampton two or three years ago and it’s testing times, but it’s up to us to pull the lads through.
"I know the level well, having played in League Two for most of my career. We need to stay calm and try to enjoy the football and I am sure we’ll come good.
"I haven’t seen much of Cheltenham this season, but I know there is pace in the side and if they can put the ball in the right areas I’ll be on the end of it, that’s my game.
"It’s not the first time I’ve been out on loan, so I’ll just get to know who all the lads are and look forward to Saturday. I tend to start well and I’ll be looking to do the same again."