It’s a little ironic that adrenalin-fuelled, sometimes dangerous extreme sports like windsurfing, kiteboarding and skiing also have a very pedestrian angle to them: it’s hard to do them when the weather isn’t quite right. There have been apps developed to try to meet that challenge by tapping into weather data providers, but sometimes these don’t actually give a personal feel of how the wind or water in a particular place can be, so two extreme sport enthusiasts, Katerina Stroponiati and Yiannis Varelas, who also happen to be techie-minded, decided to take matters into their own hands.

The result is Weendy: an extreme sports weather app that mixes weather observations from more traditional sources — such as weather stations — with crowdsourced observations generated by Weendy users.

Launched first to cover watersports like windsurfing and kiteboarding (since this is what the two Greek founders love to do most themselves), the founders have picked up an angel round of $240,000 led by Archimedes, and they are now in the process of raising another round, both of which they plan to use to continue to expand the app to cover more sports and more parts of the world, with ever more ways of depicting how good (or bad) conditions may be.

One of the unique elements in Weendy is how it turns extreme sports — already a clubbable pursuit — into something of a social network in itself. Those who sign up to the app, which is free to download, can use Facebook to sign in and then find and follow their friends on the app, or they can use Weendy itself to find and follow people based on sports or current location.

These all become weather data points. ”Kiteboarders have to search in several websites, Facebook pages, and more in order to find the info they are looking for,” says Stroponiati. “In Weendy they are connected with people like them who can actually help them.”

People use the app to write updates on particular locations, and post photos and videos as corroborating evidence. That makes it something that people are likely to do anyway, as they would with Facebook or any other social network that compels people to share their experiences. Then, triangulated with traditional weather data — which the pair say can be up to 50% inaccurate because of microclimates and the lack of scale of weather stations – Stroponiati (a user experience designer, who previously had trained as an architect) and Varelas (an engineer, who has worked on projects as diverse as voice recognition services prior to this) believe that this gives the most accurate and most relevant kind of weather assessment for people just like them.

And, as befitting a pair who are from Greece but both spent time in Silicon Valley, the idea is for Weendy to be a global community — another point that sets them apart from many of the other extreme sports weather apps, which often focus on specific locations.

There is another trend that Weendy underscores. With app stores like Apple’s and Google Play pushing 1 million apps in total each, we have long passed a point at which it is very hard for most general interest apps — for example, weather apps — to make it big, let alone pick up much traction at all. In that regard, turning to specific, niche interests, like extreme sports, makes sense.

This makes sense in another way, too: Varelas believes that crowdsourcing weather only really works when you have a targeted group contributing. “Others who who are trying to create crowdsourced weather services are not delivering, and the main reason is because they are not targeting who is getting the information, and who is providing it.” In other words, my view of the rain is not necessarily going to be the same as yours, if I’m going out hoping for a tan and you were hoping to get out of watering your flowers.

Since launching Weendy at the end of last year, Stroponiati says that user numbers have seen 20% growth week to week. Their aim is to have 1 million users by the end of this year.

The pair plan to launch an update to the app during the MaiTai Utah snowkite surfing-meets-tech-entrepreneurs-event — so expect there to be snow-specific tweaks worked into the product. “We then intend to replicate the strategy to other verticals,” she says.

As for how the app will monetize, it looks like it will go the way of sports themselves: sponsorship. There are equipment makers and sports drinks companies already in discussion with Milkybay (the name of Stroponiati and Varelas’ company), in which they will either sponsor sports on the app, or be promoted in other ways. And the pair are also talking to famous pros to act as “ambassadors” for the app and interact on it as well.

More: Weendy, An Extreme Sports App That Merges Crowdsourced And Actual Weather Data, Gets $240K Led By Archimedes