In Cydia, download "weather icon". This will put the live weather (temperature) on top of your weather icon on the home screen. Next download "klear weather icon theme" in Cydia. This will put the current weater conditions (sunny, rainy, cloudy etc images) on the weather icon. This method is really easy because you don't need to SSH into the phone and edit a string file to add in your zip code or city, instead it just uses the first city listed in your stock weather app, so be sure yours is on top.
You can add the weather to the status bar next to the battery icon, like you saw in my screenshot, by going to Settings -> Weather Icon -> and turning "Status Bar Image" and "Status Bar Temp" on. On the same screen, be sure the "Application" is set to "iPhone Weather" and the "Weather Icon" is on. You can change the refresh time from anywhere between 1 minute and 6 hours.
I see under weather icon there is an option to refresh...does this really do anything? The weather doesn't update unless you go into the actual weather program, then it updates on the screen and in the status bar....am i missing something, or is that correct?