I happened to book a flight to Denver to see a friend. I decided to visit Badlands National Park as it is 6-7 hours drive and I've never been to Great Plains before. As the trip is this weekend, I'm now contemplating if it is alright to visit this place during this time. Is starting November alright or bad time ? Especially considering how windy the place is.
November should be fine for visiting Badlands National Park, provided you're prepared for whatever the weather happens to be.
The park is open year-round, though some facilities are only open in the summer, and most events take place only in the summer. But hiking, camping, and the in-park hotel are available year round. (For other ideas, see the park's official list of things to do.)
As for the weather, while average high and low temperatures in November are 10°C and -3°C respectively, weather in the Plains states can vary dramatically. You could find yourself in a 30°C degree heat wave or a -30°C degree blizzard. And it's not unusual for dramatic shifts in weather to be just a few days apart. Check the weather before you go, dress in layers, and bring extra clothing in case it gets colder than predicted.