The iPhone Weather application allows you to quickly view the local weather and a five-day forecast. It shows the forecasted high and low temperature, and a weather icon, such as sunny, or partly cloudy.
Also: Having trouble understanding what a weather icon means? This page of iPhone weather icons may help.
You can have several locations in the weather app. Just press and flip to the right or left to move between locations. The dots at the bottom of the screen show how many locations you have, and the white dot shows your position in the locations list.
If you click on the i button at the bottom right, you can see the cities you are following, and click on the button to the left of each to delete them. You can also press and drag the right side of each item to move it up and down in the list. The bottom of the screen allows you to switch your preference between Fahrenheit and Celsius.
You can also click on the + button at the top of the screen to look up another location and add it to the list.
Weather data is provided by Yahoo!.