Did you try both weather service options? The Google one never works for me. Did you try setting your 'define weather location' manually and running test for settings? Mine crashes and burns sometimes. I went back to simi for weather info.
Almost any weather widget acts that way for me when first installed. Usually I can deal with it by turning on GPS and going to Maps. Once I make sure the Maps app is seeing my location, I go back to the weather widget and try to force update it. If that doesn't work, often I find it has updated itself a couple hours later (presumably after its regular update interval came round). I have no idea which parts of this process are actually doing anything and which are just superstitious ritual.
I believe force updating has been suggested for fixing it. I know personally on my X, minimalistic text + tasker will not update unless the screen turns on; I don't use mt's personal weather settings though, so I don't know if it requires that too.
