The code for the free version is older than the Plus version. You can
wait for it to be updated, find a close city with weather data, or buy
the plus version.
What I'm surprised at is that there's no indication on ObjectDock product page that the Free version gets updated less frequently than Plus version. Is that an internal assumption that people who use Free version shouldn't expect as many updates?
In the comparison table on this page: https://www.stardock.com/products/objectdock/information.asp may I suggest that you add something like "More frequent updates" and put a tick under Plus. Though, as I've come to discover, "frequent" is a relative term...