Today is unsettled

      "'Today is unsettled.' Have you ever heard that?" Mr. K stood in the kitchen, looking out of the window at the sky, and asked me that while I was reading an article on my computer. He startled me a little and I couldn't quite take his words in, so I said "What?"
      Earlier he did say he had a lot of work to day today, so mentally I was deciphering his words as "I'm going to be very busy today," but I wasn't very sure. I sat in the family room, looking at him, and I guess I looked puzzled, so he then said, "It means 'It's cloudy.'" Now I was intrigued, so I asked him, "Where did you hear that from?"
      "My mom. She used to say that quite often when it's a weather like this," he said.
      "How about your father? Did he say that too?"
      "No."
      "So it's your mom then."
      I wanted to know if its his mom's idiolect or a set phrase, and before I asked it, he continued on, "Yeah. I don't know where she heard that from." I found this topic quite interesting, so I asked him further about this usage. "The weather is unsettled" is another way of saying it. Some further investigation:

http://www.ldoceonline.com/dictionary/unsettled
http://www.learnersdictionary.com/search/unsettled

I also looked out at the sky. Hum.... Windy, cloudy, still bright, some small patches of blue.... (like this:)
(More patches of blue just a few moments ago)