The East Yorkshire club were competitive throughout the contest which was played in filthy conditions and not decided until Joe Philbin’s 79th minute try.
However, that came after Hull’s Joe Westerman spilled coming away from their own line and it summed up the persistent issues for Lee Radford’s side; they simply made too many errors in the relentless rain.
Earlier, as they chased the crucial try they needed when trailing just 16-14 in the late stages, Mark Minichiello coughed up the ball just after earning a drop-out.
It would cost them dearly. Likewise, Jake Connor made two mistakes to give the ball away for two Warrington tries and, so, it is the Wolves, who were beaten by Hull in the 2016 final, who return to Wembley hoping to make up for last year’s shock loss against Catalans Dragons.
They sprang a surprise by naming England full-back Stefon Ratchford who has been out since near the end of May following shoulder surgery and was not even in their 19-man squad.
But winger Josh Charnley suffered an injury in training and Steve Price brought the No1 straight into his side.
Hull saw Albert Kelly back at stand-off and England’s Connor was left out, having to start on the bench.
Warrington, who generally dealt with the rain better in the second period, had moved 16-8 ahead following Toby King’s 50th minute try.
The Huddersfield-born centre had claimed Blake Austin’s crossfield kick far too easily as Bureta Faraimo remained grounded and Stefan Ratchford improved.
Austin’s kicking game had helped Warrington take control, the Man of Steel frontrunner keeping Hull back near their own line as he continually targeted Faraimo.
But Radford’s side grew back into the game; Faraimo had an effort ruled out for obstruction before Ratu Naulago got one hand - but not enough - to Kelly’s teasing kick behind the goalline.
Still, they did reduce the deficit when Wolves erred trying to negate a kick, gifting them another set to apply pressure.
They didn’t need much of it, Danny Houghton ushering Scott Taylor over from close range on the second tackle with a cleverly disguised pass in the 67th minute.
Marc Sneyd improved and Jamie Shaul though he had put his side ahead when he crossed in the very next set after Connor’s flick pass on the last.
However, Robert Hicks deemed the ball had initially gone forward as Connor and Josh Griffin both challenged for a kick.
Radford’s side - third to Warrington’s second in Super League - pressed and pressed but there was no finishing touch and those mistakes hurt them.
They were 10-8 down at the break and the game had been as tight as the scoreline suggested.
Warrington claimed a seventh minute lead when Bryson Goodwin dived in at the corner, Naulago having made a rare error, spilling coming away from his own line on the first tackle.
That early setback did not deter Hull, though, who quickly responded with the first of Sneyd’s three goals.
They should have done more, too, when Shaul made a stunning 40m run from dummy-half but the full-back lost the ball after shrugging off Ratchford.
Moreover, when Warrington’s Ben Currie lost on the first tackle after a penalty, Kelly wasted another good chance, firing put a pass that hit Jordan Lane’s head.
Radford’s side did, however, get the try their efforts deserved in the 25th minute and what a try it was.
From a standing start and with minimal space, Naulago left former Hull winger Tom Lineham standing to escape down the right touchline.
He was tackled but Kelly’s superb shallow crossfield kick was fired across field for Bureta Faraimo to claim on the full.
Sneyd could not convert but, in the next set, forced a drop-out with a well-placed downfield kick and, when Warrington struggled to contain Kelly close to the line, he tagged on another penalty.
But when Connor was deemed to have fumbled playing the ball, Warrington hit back as Currie rose between static defenders to claim Dec Patton’s shortened kick in the 34th minute.
Ratchford improved and his side went in two points ahead after Sneyd failed to convert a difficult 40m penalty with the last kick of the half, Warrington, for the second time, having infringed when in possession.
But as much as they tried, Warrington were always just ahead in that second period and Hull must now instead concentrate on challenging for a maiden Super League tite.
Warrington Wolves: Ratchford; Mamo, King, Goodwin, Lineham; Austin, Patton; Hill, Clark, Cooper, Currie, Hughes, Clark. Substitutes: Philbin, Murdoch-Masila, Davis, Tasi.
Hull FC: Shaul; Naulago, Tuimavave, Griffin, Faraimo; Kelly, Sneyd; Taylor, Houghton, Paea, Lane, Minichiello, Westerman. Substitutes: Ellis, Bowden, Fash, Connor.
Referee: Robert Hicks (Oldham)