This may be an inconspicuous bug on the iPhone.
It was first discovered by Gui Rambo. Simply put, when you use Fahrenheit, the weather app that comes with the iPhone cannot display 69° correctly. Instead, it will display approximately 68° or 70°.
Although it seems to have little effect, people are curious about the reasons behind it.
According to an incomplete summary, iOS 14.6 and some earlier versions will have this problem. New systems such as iOS 15 Beta 2 can display correctly, and earlier systems such as iOS 11.2.1 can also display.
Here are several analytical opinions on this:
1. A former Apple developer, Joo Pavo, judged that this may be related to the conversion of degrees Celsius and Fahrenheit, because 69°F = 20.5555555ºC, the weather APP uses Celsius to count, and Fahrenheit is converted.
According to this theory, 65°F display should also be BUG, because 18°C=64.4°F and 19°C=66.2°F.
2. Apple’s intentional humor
What’s interesting is that 69°F can’t be displayed correctly only in the weather app. It’s normal to jump to the Weather website that provides weather data. In addition, Apple’s other weather APP, Dark Sky, can also display 69° correctly.
Left: iOS 14.6 Right:iOS 15 Beta2
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Sean Lee 
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