A $20 Weather Station

Jan 2016 note: We no longer endorse StormTag. Regrettably, in the time since posting the below, Hex3 have become slower and slower in their responses. Over the past several months we have no update on the status of StormTag, to our knowledge no-one who pledged on KickStarter has received a StormTag. We did not invest any money in, or stand to benefit financially from StormTag.

We leave the below as a historical record of developers caught up in the enthusiasm of a product that may never see the light of day (perhaps ironically, one of the things it was meant to measure).


At WeatherSignal we turn phones into weather stations. The WeatherSignal app takes readings of device sensors such as light, pressure, temperature and humidity from devices and uses these to create crowd-sourced weather maps. But there’s a problem, we’re limited to the sensors on each device. This is changing.

We’ve teamed up with StormTag, who’re building incredibly low cost, low power, waterproof temperature/pressure sensors that communicate via Bluetooth LE. We’ll be incorporating StormTag compatibility into WeatherSignal, we’re also committing to building an iOS version of WeatherSignal to support StormTag. We’ll be working closely with the makers Hex3.co to ensure good battery life on device and sensor and a smooth experience.

At the time of writing, after 6 hours of being live this project is 1/3 funded with $5k committed. Thanks for your support!

StormTag means that everyone with an Android or iOS device will be able to monitor temperature and pressure. These are key weather variables – pressure in particular plays the key role in determining weather flows, and in predicting and monitoring extreme weather events. We believe crowdsourcing this data will provide a dataset that far exceeds the resolution of professional weather stations.

Support the StormTag on Kickstarter and get it for $20

Following feedback form early backers and discussions with the engineers, Jon has decided to offer a StormTag+ for $35, the extra $15 allows the addition of:

  • Up to 10 days data logging. Weather data is stored in onboard memory when your phone or tablet is not connected to StormTag+.
  • Humidity Sensor: to provide more accurate forecasting and more complete data collection.
  • UV sensor: StormTag+ will now know if it is outside and provide even more valuable data.

The current state of temperature and pressure sensors
On Android our own research (based on millions of phones and tablets using OpenSignal) indicates that 74% of phones do not have a pressure meter. On iOS not a single device has a pressure sensor, although there are rumours the iPhone 6 may come with one. This means only a small proportion of smartphone users can currently contribute to our weather maps.

Temperature sensors are even less common, only about 1/10 devices currently have one (the Galaxy S4, Moto X and Galaxy Note III being the market leaders). However it’s quite likely this percentage will decrease. Unlike its predecessor the Galaxy S5 does not have a temperature sensor, the Galaxy Note 4 will probably also lack a temperature sensor. The next generation of leading Samsung devices do not have temperature sensors.

The StormTag is not the first project to enhance smartphones with external sensors, Robocat raised over $300,000 to provide a thermometer add on, Thermodo. Since then other projects have added wind and (most crucially) pressure sensors. But we think the StormTag can reach a far larger audience.

StormTag Features

  • Pressure and temperature sensors powered by a button cell (anticipated battery life in years)
  • StormTag+: humidity and UV sensors also included
  • Lowest price point of any sensor add-on with these capabilities
  • Bluetooth LE means it can monitor the weather passively, unlike other sensors that plug in via the headphone jack
  • The fact that it is waterproof and can be worn away from the device (rather than attached it) mean the temperature readings are more reliable
  • Using the headphone jack to collect data, can be problematic – it typically requires the device providing sufficient power through the jack
  • StormTag+: 10 days data logging – leave the StormTag+ outdoors, in your baot, in a Stevenson Screen – when you’re back you’ll be able to pick up the data with your device.

It’s important to note StormTag will only work with Bluetooth LE devices – this includes all of the iPhone 5 range and most new high end Android devices (HTC One, Nexus 5, S5) along with a lot of cheaper ones. We’re expecting to see the number of devices with this technology trend strongly upwards as iBeacons and other Bluetooth beacons gain ground.

If you love sensors, you’ll know about some of the other players in the market already, here’s a rundown:

Pressure Temp. Humid. Light Gas Wind Connection Size Price
StormTag Bluetooth LE Tiny $20
StormTag+ Bluetooth LE Tiny $35
SensorDrone Bluetooth LE Small $200
Node Kore with Clima module Headphone jack Medium $225
Thermodo Headphone jack Tiny $30
Shaka Weather Station Headphone jack Medium $100
Vaavud Headphone jack* Medium $60
Weatherflow Windmeter Headphone jack Medium $35

The Vaavud uses the headphone jack as an axis to rotate about, but does not communicate via the headphone jack (it uses periodic distortion of the magnetic field around the phone caused by its rotating magnets)

If you’ve read through all this, you should really back the project on Kickstarter and download the WeatherSignal Android app.

Here’s the KickStarter video:

This entry was posted in Sensors, WeatherSignal. Bookmark the permalink.

Leave a Reply