When you enable the Local Forecast feature in the Weather app, it will constantly use your GPS to determine where you are at and show you the weather. If you are not travelling, you can turn this off and just manually add your home city and it will give you the same info. To change this setting go to Settings > Location Services > Weather.
I noticed a pretty significant improvement in battery life by disabling this feature.
On a different note, I did a quick road trip from Dallas to Indiana and enabled this feature - and it was very handy to quickly check the weather - I had car charge in hand so all was good.