StormTag is a key-fob sized sensor for measuring weather data that’s designed to contribute to a crowdsourced network of other sensors to map aggregated weather data and offer localized predictions. It works with Bluetooth LE smartphones and tablets to sync its data back to the cloud where users can view weather info in an app.

The StormTag sensor come in two versions: the basic StormTag, which includes a temperature and barometric pressure sensor and costs $25; or the $35 StormTag+ which also includes a humidity sensor, UV sensor, and on-board memory so it can log data for as long as the battery lasts and sync it later to a phone or tablet.

StormTag is currently a prototype while its makers run a Kickstarter crowdfunding campaign to get the device to market — aiming to ship to backers in November.

Flagship smartphones are getting increasingly sensor packed these days. Samsung added temperature, pressure, and humidity sensors to its Galaxy S4 device last year, for instance, giving it the ability to measure weather data. But there are plenty of lower priced handsets that don’t have such a fancy array of sensors — which means there’s scope for a standalone device that contains the necessary hardware and syncs with a smartphone to ferry its enviro data load up into the cloud.

Add to that, phones are often kept tucked away in a bag or pocket, rather than deliberately left exposed to the elements, so a standalone sensor for environmental data logging makes some sense.

StormTag is aiming to be such a standalone device — competing with the likes of CliMate. Both devices are currently raising funds on Kickstarter, but StormTag has already more than doubled its original funding target of $17,500, so has the money to make it to market in the bag already — still with well over a month of its crowdfunding campaign to run.

StormTag is another hardware project from Jon Atherton, whose prior successfully crowdfunded creations include the YuFu, Nota and JaJa styli, and — more recently — an e-ink Bluetooth bedside clock, called aclock.

Atherton says he’s recycling some of the parts used in the YuFu stylus for StormTag — specifically the pressure sensitive electronics — which has allowed him to bring the StormTag to market with a relatively low funding target. CliMate, by comparison, is shooting for a $50,000 raise.

Atherton is also partnering with crowdsourced weather map WeatherSignal so users of StormTag get access to data being generated by WeatherSignal’s network of environment-sensor equipped Android phones from the get-go, to help circumvent the problem of needing a large uptake before StormTag starts generating useful data. It also means he doesn’t have to build his own app since WeatherSignal will be taking care of the end-user software.

“WeatherSignal already have a large body of data — and we will be adding to that with users of iOS other Android devices that don’t have inbuilt sensors,” says Atherton, nothing that the WeatherSignal app has 50,000 active devices, and 230,000 total installs.

“Globally, WeatherSignal is averaging out at just around 2 million readings per day. Note — each reading is a timestamped, geolocated set of sensor readings — so a single reading covers many sensors, so there are several million data points per day already stored in WeatherSignal. So StormTag builds on this WeatherSignal data.”

Atherton is giving the StormTag crowdsourced weather project a two-year timeframe to build into a really useful hyperlocal weather forecasting ecosystem.

“My two year target is to have accumulated enough historic data that we can do useful predictions using just one StormTag — we’ll also be building out the crowd sourced weather predictions and mapping,” he says, adding: “In the interim, we’ll be delivering some fantastic data to our users, as well as hyper local readings.”

The StormTag has a hole in it so it can easily clip onto keys or clothing, and is being designed to be waterproof so it can be used outdoors in scenarios like skiing or boating.

With StormTag’s funding target already met, Atherton says he’s kicked off the production process already — and reckons he’ll be able to deliver it to backers earlier than scheduled.