I am really confused by some of the new data returned in WeatherKit for iOS 18. The visibility (of an object) was already being returned in HourWeather as a Measurement. iOS 18 added max/min visibility (of terrain) in DayWeather. BUT instead of a Measurement it's just a Double. HourWeather: /// The distance at which an object can be clearly seen. /// /// The amount of light and weather conditions like fog, mist, and smog affect visibility. public var visibility: Measurement<UnitLength> DayWeather's comment: /// The maximum distance at which terrain is visible for the day. /// /// The amount of light, and weather conditions like fog, mist, and smog affect visibility. @available(iOS 18.0, macOS 15.0, tvOS 18.0, watchOS 11.0, visionOS 2.0, *) public var maximumVisibility: Double This makes it sound like the new items are also a distance and not a percentage. Why wasn't Measurement used so the unit would be clear? Documentation doesn't explain this either. I'm hoping that this isn't being returned in the unit used by the current locale because my app lets you specify what unit to use for temperature, length, etc regardless of locale. Since all the temperature, length, etc data returned had used Measurement that was possible. The iOS weather app refers to the lowest/highest visibility in my preferred unit, which is miles.

I filed FB16332997 about the VERY high snowfall estimates I'm seeing in WeatherKit and iOS Weather. I initially thought something was wrong with my weather app but I verified the numbers with the iOS Weather app and another third party weather app. For Atlanta last week it was saying 7.5" when it ended up being 2" (which I can live with). Two days ago it reported there could be 16" of snow in northern Florida. That's impossible! This morning it was reporting that Niceville could have 6-7" of snow, which would be significantly more than highest amount in recorded history for Florida (where snow is extremely rare). It almost makes me wonder if the liquid precipitation value is actually the snowfall amount in reality. And then that is incorrectly being converted to the snowfall amount.

I just noticed something really odd with WeatherKit. If the temperate at midnight of the FOLLOWING day is colder than all temps in the day you want weather for then WeatherKit will report that as the low temperature for the day even though it's a different day. Here it's reporting the lowest temp for Feb 6 is 22F. But that's a temp from Feb 7. I'm displaying lowTemperature and lowTemperatureTime from DayWeather as well as the HourWeather in these examples. I wasn't sure if this was working as designed or a bug. I can provide raw data from this example. ----daily formatted start weather for Feb 6 High 41° high at Feb 6 at 2 PM Low 22° low at Feb 7 at 12 AM ----daily formatted end Feb 6 at 12 AM 34° Feb 6 at 1 AM 35° Feb 6 at 2 AM 36° Feb 6 at 3 AM 36° Feb 6 at 4 AM 36° Feb 6 at 5 AM 34° Feb 6 at 6 AM 33° Feb 6 at 7 AM 33° Feb 6 at 8 AM 33° Feb 6 at 9 AM 33° Feb 6 at 10 AM 35° Feb 6 at 11 AM 36° Feb 6 at 12 PM 38° Feb 6 at 1 PM 40° Feb 6 at 2 PM 41° Feb 6 at 3 PM 40° Feb 6 at 4 PM 39° Feb 6 at 5 PM 37° Feb 6 at 6 PM 36° Feb 6 at 7 PM 33° Feb 6 at 8 PM 31° Feb 6 at 9 PM 29° Feb 6 at 10 PM 27° Feb 6 at 11 PM 24° Feb 7 at 12 AM 22°