The weather application on your Apple iPhone is a default app that allows you to add multiple locations to the application. It provides a six-day forecast and high and low temperatures in both Fahrenheit and Celsius. This tool is linked to the Weather Channel and continuously updates the forecast as new information is available. Since the default city for the iPhone is Cupertino, California, you'll need to adjust your weather settings once you've activated your phone. For a third-party weather application, you can download a weather application from the App Store.
Press the "Home" button on your iPhone and tap the "Weather" icon.
Tap the "i" icon in the lower-right corner to add additional cities. Tap the "+" button at search for a city and type in the name of the city you wish to add. Tap the city in the search results to add it. Tap the "-" button on the left side of the city to erase a city.
Tap the "C" button to change the weather display to Celsius, and tap the "F" button to change it to Fahrenheit. Tap the "Done" button in the upper-right corner to complete the setup.