Winds gusting to near 50 mph Monday afternoon swept cooler air across the region. Midday temperatures peaked around 50 degrees, then lowered to the low 40s by evening. The influx of colder air will remain in place through Tuesday, setting up what is expected to be the area’s chilliest Halloween in 21 years. Temperatures near freezing early in the day will struggle to reach the lower 40s, a level about 14 degrees below normal. Though cold, winds will diminish, and those venturing out in the evening are expected to stay dry. Conditions will be much less wicked than some Halloween’s, half of which feature rain. The area’s worst Halloween weather occurred in 1994, when howling winds and driving rain swept the city, while suburban locations were plastered with a coating of slushy snow.