Eric Floehr, founder of ForecastWatch, tells Mic that each app gets its forecast from different places, utilizing different prediction models and relying on different meteorologists to interpret the data. “The big weather apps like AccuWeather, The Weather Channel and Dark Sky all create their own forecasts,” Floehr explains. Some of those services also sell their forecasts, which apps like Yahoo’s weather service and WeatherBug repackage in their own app — but that doesn’t guarantee agreement, either.