With the turn of the New Year, Apple closed down Dark Sky for good. Apple acquired the app in 2020 and left it up and running until January 1st as it incorporated the app’s radar and real-time forecast features into its own Weather app. Dark Sky’s API, which was used by many third-party weather apps, was discontinued at the end of 2021 and was subsumed within Apple’s own WeatherKit API, which debuted last fall.

Over the holidays, Slate took a look at the app’s indie success story, which began with a successful Kickstarter campaign in 2011 that raised $40,000. One thing that I didn’t realize about Dark Sky is that its short-term precipitation forecasts were based solely on analysis of radar images, which didn’t win it fans among meteorologists:

Indeed, Dark Sky’s big innovation wasn’t simply that its map was gorgeous and user-friendly: The radar map was the forecast. Instead of pulling information about air pressure and humidity and temperature and calculating all of the messy variables that contribute to the weather—a multi-hundred-billion-dollars-a-year international enterprise of satellites, weather stations, balloons, buoys, and an army of scientists working in tandem around the world (see Blum’s book)—Dark Sky simply monitored changes to the shape, size, speed, and direction of shapes on a radar map and fast-forwarded those images. “It wasn’t meteorology,” Blum said. “It was just graphics practice.”

I hadn’t used Dark Sky in years when Apple bought it, except as a data source in other weather apps. Its forecasts may not have been as nuanced or accurate as a meteorologist’s, but there’s no denying its cultural impact on the world of apps, which is why I’ll be tucking this story away in my app history archives.