The futures for Dallas Heating Degree days for July 2022 are trading around 6.83
But Dallas is hot in July and does not typically get any heating degree days
So, what does the 6.83 for July 2022 correspond to?
Are you sure these futures are trading? There is no data on BBG - or the CME.
I have no experience with these products, but I am almost certain that there are no quotes (and hence no trading) for July weather futures for Dallas at the CME.
I don't think it's CDD either (should be a lot higher - around 480 according to the second link in the question, which seems reasonable) but just bad data. According to the CME, the contract months for HDD are Nov, Dec, Jan, Feb, Mar plus Oct and Apr only.
CME's official WEATHER Products code sheet also shows no such thing as a H5 N22 (Dallas June 22 future) as your link claims.