I noticed that with my old phone. AccuWeather is the best app, but every few months or so, it just decides to take a short vacation. Just as I'm frustrated enough to replace it, it wakes up again. Who knows?
I don't see any time interval setting on mine. I have auto-sync on, I'm in WiFi all day, I've reinstalled the widgets (Samsung and AccuWeather) repeatedly.
Would be nice to just look at the phone and see the weather, as promised.