San Francisco’s micro-sub-mini-climates are solely responsible for the zipper wear on your favorite light jacket; we're constantly readjusting our outerwear as we battle temperature differences between neighborhoods. Luckily, our neighbors to the north are working on a crowd-sourced key to our 99¢ mood ring version of climate, called PressureNet. Although micro-temp apps already exist – SF Climates, for instance – their data is collected from a handful of relatively expensive personal weather devices mounted on private roofs throughout SF as part of the Weather Underground

The Vancouver, Canada-based app developers behind PressureNet are doing something very different, using the pressure sensitive barometer contained in the latest line of Android 3.0+ smartphones to accurately measure a phone’s surrounding temperature, indoors or outdoors, studio or penthouse. The information is sent to a citywide map used to project weather forecasts that display current conditions for the exact city block you’re on. Although the crowd-sourced app is still in its infancy, the collected data could be invaluable for researchers and paves the way for passive contribution in exchange for relevant information, something already seen in traffic/accident type apps like Waze and Google Maps. 

Below is an example of what the app looks like for Vancouver. The creators posted the image on Reddit hoping to encourage San Franciscans to sign up.

Unfortunately, iPhone users are left out of the game, as even the latest version is devoid of any pressure sensitive tools (although the rumor mill says that the iPhone 6 will include the same type of barometer found in Androids). Another issue is the current lack of users. Creators Jacob Sheehy and Phil Jones say that for the project to actually work and be usefully accurate, they’d need millions of users continually supplying data, meanwhile the app shows 50k-100k downloads, not nearly enough. This is probably why they were asking San Francisco Redditors to join the cause. 

In the meantime, PressureNet’s creators have gotten some interesting requests for the data they’ve collected from researchers and weather forecasters, but the information is surprisingly not open source. Partially because the original data collection was done without permission, and partially because they’ve yet to determine how much to charge interested parties for access to that information.

The far reaching implications of this idea are also useful in predicting rapidly changing weather conditions, such as a storm or hurricane. Currently we’re able to understand them with a somewhat reliable pattern based measurement system, but Cliff Mass, an atmospheric scientist at the University of Washington, told Wired last year that the app may make it easier to predict weather events up to six hours in advance, something currently impossible with today’s in-use technology.

To paraphrase and butcher Mark Twain, “If you don’t like the weather in San Francisco, move over three feet.” And if you want to know which direction to move, check it out with apps like SF Climates or PressureNet.

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Image from Thinkstock