We are using Qlik Market's Weather and Demographics data and I've checked few other options before that.
There are tons of local Weather reporting sites. I would start at National Weather Service site where you can see multiple options to get your data.
For Demographics: https://www.census.gov/ should be a good start.
Again, there are a lot of options out there, but you need to decide if you want to spend your time researching these data sources or purchase a Qlik Data Market feed (especially considering international data options...).
Qlik Data Market has some flaws and there are other paid data sources out there (I've found the Weather Forecast New York City - Foreca.com site provides more information, for pretty much the same price as Qlik DM)...