If you plan to go trick-or-treating Saturday night the weather should be perfect. Bring a jacket. There's a small chance that you could get wet on Sunday.
High pressure will keep us dry and mild across the state through Saturday. Then a weak weather system will cross northern Utah Sunday, bringing the chance of a few weak, brief rain showers.
FRIDAY: Conditions will be dry and mild with temperatures a few degrees above average.
SATURDAY: High clouds will increase across northern Utah. But it should stay dry with a slight breeze. Highs will be near 66 in northern Utah with a low around 47. In southern Utah it should be dry with a high near 78 and a low near 48.
SUNDAY (HALLOWEEN): It will be a slightly cooler day. Northern Utah will experience a modest increase in moisture, bringing the chance for showers Sunday afternoon through Sunday evening. In southern Utah, conditions will stay mostly sunny with a high near 76 and a low near 54.