Challenge Cup final: Montpellier v Ulster, San Mamés Stadium, Bilbao, Friday, 9pm local time/8pm Irish time – Live on ITV4 and Premier Sports 1This is Irish rugby’s first two-pronged assault on the host city for European rugby’s showpiece double-header. But the first tranche of supporters from Ulster and Leinster had only to set foot in Bilbao in order to appreciate one additional factor for their teams to cope with this weekend. The weather.With temperatures in the mid-30s on Thursday afternoon, even passing the shimmering and shiny lego-like grey bowl that is the San Mamés Stadium at teatime, it was still over 30 degrees. Friday will be almost as stifling, and despite the 9pm kick-off local time, the temperature for the start of the Challenge Cup final will be 27 degrees.Although Saturday is not forecast to be quite as hot, the forecast is for 27 degrees again when the Champions Cup final kicks off at 3.45pm local time, a time to suit France TV’s free-to-air television coverage so as to avoid clashing with their coverage of the Cannes film festival’s closing ceremony. Sacrebleu!One would have to conclude that these conditions will also suit both French finalists, Montpellier and Bordeaux Bègles, whereas they will be fairly alien and demanding for Ulster and Leinster. This is most definitely not Irish weather.Attitudes toward the Challenge Cup can vary, be it from teams that take the competition indifferently or seriously, or those whose interest heightens the further they progress. But come the final, there’s no doubting the Challenge Cup’s importance for the last two teams standing.First and foremost, this is a chance to win a trophy, as Montpellier have twice demonstrated in the past. For Ulster, winning the Challenge Cup would see them win silverware for the first time since their 2006 Celtic League success – the longest trophy drought of any of the four Irish provinces.Winning the Challenge Cup also offers an alternative route into next season’s Champions Cup, but whereas Montpellier sit second in the Top 14 and are thus certain to qualify, not so Ulster. It seems a little cruel that Richie Murphy’s side have ended up ninth on 52 points and missed out on the URC playoffs after such an entertaining and promising campaign, and given the threshold in the last four seasons has been 48 points and 50 points twice apiece.Robert Baloucoune stretches during the Ulster captain's run at the San Mamés Stadium in Bilbao. Photograph: Nick Elliott/Inpho Hence, Ulster have to win this final to earn qualification for next season’s Champions Cup, which in turn would be at the expense of Connacht, unless they win the URC outright, and that would be even crueller given Stuart Lancaster’s side accumulated 54 points.In the heel of the hunt then, this is both Ulster’s last game of the campaign and the game that will most define their season. At least that brings clarity. Come kick-off, there will be no tomorrow for their season.They are missing the experienced quarter of Stuart McCloskey, Jacob Stockdale, Rob Herring and the suspended Iain Henerderson, which is also a cruel blow for them individually. Even so, unlike a week ago in their 26-22 loss to Glasgow, Murphy is putting out a stronger-looking frontline team from the off. The fit-again Robert Baloucoune returns for his first game since his breakthrough Six Nations, as does Jude Postlethwaite, which should facilitate Ulster’s offloading game in the absence of McCloskey. Halfbacks Nathan Doak and Jack Murphy, along with Wallabies loosehead Angus Bell and Cormac Izuchukwu, all start after being held back on the bench last week. David McCann and Juarno Augustus are also restored.It’s a strong team. There is clearly no holding back, albeit the bench looks a little callow. Ethan McIlroy’s greater versatility sees him retained and so Werner Kok has played his last game for the province.Montpellier are actually the form team in Europe with seven wins on the bounce in both competitions. But despite sitting second in the Top 14 and next weekend hosting Pau, just a point and a place behind them, they look fairly locked and loaded compared to their 18-12 semi-final win over the Dragons with what looked like a second-string team.One of those seven wins was an impressive 23-21 away victory against Bordeaux Bègles, and all but two of that starting line-up have been picked to start this game, one of the exceptions being their fit-again, talismanic captain Lenni Nouchi.Montpellier's Argentinian outhalf Domingo Miotti during the captain's run on Thursday. Photograph: Nick Elliott/Inpho Yet he shifts to blindside as the much-decorated former Saracens, England and Lions number eight Billy Vunipola returns to captain the side in one of only three changes in personnel from the starting XV for last weekend’s 36-33 win away to Castres.Their Scotland and Lions scrumhalf Ali Price, and Argentinian outhalf Domingo Miotti, are retained in what is their first-choice halfback pairing. Price and Minotti also started the win in Bordeaux and the 54-22 quarter-final victory over Connacht. That remains one of only two losses in Connacht’s last 10 matches.Montpellier also have pedigree in this competition, lifting the trophy in 2016 against Harlequins in Lyon and again in 2021, when edging out Leicester Tigers in Twickenham, before winning the French Championship in 2022.You sense that Ulster will give it their best shot and though seven-point underdogs are certainly not without a real chance of winning a trophy for the first time in two decades.That would be a wonderful shot in the arm for a province which has had its ups and downs since losing the Champions Cup final in 2012 and Pro 14 finals in 2013 and 2020, all of them to Leinster.Yet the clear signs are that Montpellier, the unbeaten top seeds from the pool stages, have targeted this final. As well as the greater physicality and firepower, they should have conditions to their liking as well.MONTPELLIER: Tom Banks; Gabriel N’Gandebe, Arthur Vincent, Auguste Cadot, Donovan Taofifenua; Domingo Miotti, Ali Price; Enzo Forletta, Jordan Uelese, Mohamed Haouas; Florian Verhaeghe, Tyler DuGuid; Lenni Nouchi, Alex Becognee, Billy Vunipola (capt).Replacements: Lyam Akrab, Baptiste Erdocio, Wilfrid Hounkpatin, Adam Beard, Marco Tauleigne, Leo Coly, Thomas Darmon, Jon Echegaray.ULSTER: Michael Lowry; Robert Baloucoune, James Hume, Jude Postlethwaite, Zac Ward; Jack Murphy, Nathan Doak; Angus Bell, Tom Stewart, Tom O’Toole; Harry Sheridan, Cormac Izuchukwu; David McCann, Nick Timoney (capt), Juarno Augustus.Replacements: James McCormick, Eric O’Sullivan, Scott Wilson, Charlie Irvine, Bryn Ward, Conor McKee, Jake Flannery, Ethan McIlroy.Referee: Matthew Carley (England).Forecast: Montpellier to win.