Basically, scraping involves retrieving web pages and selecting and formatting certain information into a more useful format such as an Excel spreadsheet.
CodeRevolution is not a lawyer and nothing he says should be taken as legal advice. Consult an attorney for authoritative guidance. However, it would most likely be illegal to scrape copyrighted material and republish it for the general public. It is my understanding that facts can not be copyrighted. Therefore, you would be within your legal rights to scrape weather information for Chicago and do whatever you please with it.
Scraping is not hacking. I will not hack into data that you are not authorized to process.