Crowdsourcing weather using smartphone batteries and GPS/GNSS Location data

The OpenWeather smartphone app collects temperature, humidity
and air pressure information from users around the world combined
with GPS/GNSS location data to track weather conditions in real
time. Right now, the app is only available on Android smartphones.

As reported by Phys.org: Smartphones are a great way to check in on the latest weather predictions, but new research aims to use the batteries in those same smartphones to help predict the weather.

A group of smartphone app developers and weather experts discovered a way to use the temperature sensors built into smartphone batteries to crowdsource weather information - mashing it up with location data provided by the phone's GPS/GNSS interface. These tiny digital thermometers usually prevent smartphones from dangerously overheating, but the researchers discovered the battery temperatures tell a story about the environment around them.

Crowdsourcing hundreds of thousands of smartphone temperature readings from phones running the popular OpenSignal Android app, the team estimated daily average temperatures for eight major cities around the world. After calibration, the team calculated air temperatures within an average of 1.5 degrees Celsius (2.7 degrees Fahrenheit) of the actual value, which should improve as more users join the system.

While each of the cities already has established weather stations, according to the new method's creators it could one day make predictions possible at a much finer scale of time and space than is currently feasible. Whereas today, weather reports typically provide one temperature for an entire city and a handful of readings expected throughout a day, the technique could lead to continuously updated weather predictions at a city block resolution.

"The ultimate end is to be able to do things we've never been able to do before in meteorology and give those really short-term and localized predictions," said James Robinson, co-founder of London-based app developer OpenSignal that discovered the method. "In London you can go from bright and sunny to cloudy in just a matter of minutes. We'd hope someone would be able to decide when to leave their office to get the best weather for their lunch break."