For the most part you’ll have nice fall weather, unless it’s a weird year. Highs anywhere from 60-80 during the day, lows 30-45 at night, but you can’t be surprised to see temps in the 20’s. Not a lot of rain, and IF it snows (always a slight chance in October) it’s normally just for a night, and maybe during the early morning. Last year it was still 80’s plus during many days.
The park does not have electric sites… just be prepared in case it does get cold enough to be running a heater for a few hours at night.