Sometimes developers come up with some pretty clever workarounds to provide users the features they want, as is the case with Lock Screen Weather.
Lock Screen Weather acts as a media player by using the "cover art" display on the lock screen to display your local weather forecast.
After installing the app, launch it and you will see the Enabled switch turn on by itself. You can then set your location either by city name or current location, turn off the five-day forecast or change from Fahrenheit to Celsius.
You will also notice at the bottom of the screen the option to play a sound in the background. You can pick between silence, meadow, jungle, lake and ocean sounds. These sounds will continuously play as long as the app is enabled.
You may notice while the app is enabled, the icon which normally indicates the media player is being used and something is currently playing will be present. This is due to the way Lock Screen Weather interacts with iOS 5, displaying the weather forecast as cover art on your lock screen.
As long as the app is enabled, you can view the weather forecast on your lock screen at any time.
To turn off the background sounds as well as the lock screen weather display, launch the app again and toggle the Enable switch to off. Turning the display back on is as simple as launching the app and allowing it to enable itself again.
Lock Screen Weather is compatible with an iPhone (3GS, 4, and 4S) or iPod touch (3rd or 4th gen) running iOS 5.