Finding a weather provider who doesn't use https is only a temporary solution I'm afraid. At the rate everyone is switching to https-only, you'll get a year or two before it's blocked too.

Well, that's not true of provided APIs, which will still be in http for some time. But I gather free weather APIs weren't profitable. Makes sense, as they want you to go see their ads to be monetised. Most sites are closing down their free APIs and require payment to get an API key.