The Rapha Pro Team Ghost Air jersey is the most expensive cycling jersey that Ive tested. It builds on the previous Ghost jersey with a design specifically suited for humid environments. The Ghost Air jersey is heavily perforatedFuture - Andy TurnerThis white version is fairly see-throughFuture - Andy TurnerThere isn't a single panel that isn't full of holes for airflowFuture - Andy TurnerConstructionRapha has developed the Ghost range of kit using climate chambers and laboratories to test the body temperature of riders in the Ghost kit versus other kits. The idea behind this line has been produce a jersey that limits the impact on performance that the heat has. The standard Ghost jersey was designed to be very fast moisture wicking but was not as effective in humid heat. The Ghost Air steps it up when conditions get humid thanks to some clever construction techniques. Whereas the Ghost jersey sits flush with your skin, the Ghost Air features a series of dotted lines of material under the jersey. These push the fabric away from the skin and allow for airflow between the jersey layer and the skin. With humidity impacting moisture transfer, this improved airflow is designed to help sweat wicking when that becomes near impossible in humidity with standard lightweight materials.The jersey also features a host of perforation across the entirety of the construction. This is aimed to work in conjunction with the internal channelling to allow for air to enter and circulate, assisting in evaporative heat loss. Rapha does state the jersey is for use in 25-40 C and humid conditions, and without a base layer to work at its best. It also features the same lightweight mesh waist hem as the Ghost jersey, as well as low cut neck and three rear cargo pockets with a mesh structure around them.Sizes range from XS to XXL, while three standard colours are available as well as a special edition Ice Dye version. The RideTo really put the Ghost Air to the test, Ive made the most of the rather humid heatwaves that weve been graced with in the UK so far this summer; 34C and 60% humidity isnt the maximum of what this jersey is claimed to be able to cope with, but its a good place to start.In the recent UK heatwaves the jersey has been noticeably more pleasant in the 34C+ and higher humidity heat than other hot weather alternatives (Image credit: Future - Andy Turner)The fit of the jersey is very much in line with the Rapha Pro Team range. The rear sits a bit higher than the Classic range, but the pockets are still manageable to reach into without difficulty. At the front, the hem does sit quite high, so if you have bib shorts with a lower cut at the front like the Assos Equipe RSR then you can end up exposing some skin when standing off the bike. As with other Pro Team items the fit is close and race cut, but not constrictive.Having previously tested the standard Ghost jersey, the fast moisture wicking was a fantastic feature of that jersey with the very thin material, however it struggled to transfer this moisture when the weather was more humid. Back to back testing of the Ghost Air with that did confirm that the Ghost Air does work significantly better in that stickier humid heat. You cant escape all levels of discomfort in those conditions, but the Ghost Air jersey does do a very admirable job of reducing how stuffy you feel around your trunk. Having the raised internal structures and host of perforations does assist in allowing air to enter and flow better than any other piece of kit that Ive tested.It can still struggle a little on longer, steeper climbs as the airflow becomes a little limited by the reduction in speed. However, at cruising speeds of 25-30kph the jersey works very effectively. The waistband is even meshFuture - Andy TurnerYou can see how many perforations there are, plus you can see the internal channels through the exterior of the jerseyFuture - Andy TurnerInternally these rows of raised fabric are dashes so as to allow airflow in all directions inside the jersey, suited best for humid weatherFuture - Andy TurnerYou do need to be careful with the white jersey in terms of colour staining, especially if you have darker bib shorts that are also getting very sweaty. I did end up with some colour patches on the Ghost Air, but they washed off and it was against a new unwashed pair of dark dyed shorts. Just something to consider. Another feature I do like is the internal perforations do lead to a slight ribbed structure on the sleeves of the jersey. There is no testing to confirm if this improves the aerodynamic performance but, generally speaking, a textured sleeve is faster than a smooth sleeve, so it is unlikely that it hurts performance in any way. ValueThere is no doubt about it, this is a very specialist jersey, and that comes at a price. 275/$350 is very expensive for a cycling jersey. It wasnt long ago that a pair of bib shorts exceeding 200 was a lot, let alone a jersey that now nears the 300 mark.To put it into context, other hot weather specialist jerseys are significantly cheaper. The Rapha Ghost standard jersey is 225, Castelli Premio Evo 230, Assos Mille GTO S11 210, and Isadore Echelon Ultralight is 170. I cant say that compared to the likes of the Isadore jersey that the Ghost Air offers good value; it simply doesnt justify being 105 more for most people.Saying that, having tested a lot of jersey across a lot of conditions, I can confidently say that the Ghost Air is the best at regulating temperature when the conditions are more humid. To that end, it is a class leader, so if you want a jersey that is the best for humid conditions, this is it. But in those conditions, other factors such as head cooling are still a big limitation, and comfort is relative in 40C humid heat. The Rapha Pro Team Ghost Air will be more comfortable than other jerseys in those conditions, but I dont think its by such a margin to justify the cost for most people. But perhaps if I was doing events in hot humid conditions where I was preparing all season for it, then something that makes me cooler, more comfortable, and may enhance performance a touch might become a relatively better value item. The Ghost Air (White) features the same fit and waistband as the standard Ghost (Pink) jersey from RaphaFuture - Andy TurnerThe fabrics are very different though. The Ghost Air has those channels, while the Ghost is a thinner fast wicking materialFuture - Andy TurnerConclusionThe Rapha Pro Team Ghost Air jersey is a wonderful adventure into what is possible when it comes to creating a jersey specifically for hot and humid conditions. In weather like that, nothing is truly comfortable, but compared to the competition, the Ghost Air does a better job at keeping you cooler for longer thanks to some clever technical innovations with the fabric.Its not good value for most of us, as 275/$350 is the price of a good pair of shorts and a decent jersey. But for those who want to be as comfortable as possible in conditions that frankly are extremely uncomfortable, the Ghost Air does a better job than anything else on the market right now.