Historical weather data, all-time temperature records, and monthly climate averages for Vacaville, CA. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 4th in Vacaville typically feels like spring is settling in, with average highs around 69° and lows near 47°. The date has seen some swings though — a balmy 85° back in 1960 and a chilly 35° low in 1970. Rain is unlikely but not impossible, with just a 17% chance of precipitation.
Vacaville's summers can be punishing — the all-time high of 110° on June 14, 1961 puts it firmly in Central Valley heat territory. Winters bring the opposite extreme, with a record low of 19° set on January 3, 1968. The wettest single day on record dropped 3.18 inches on January 21, 1967.
Vacaville runs hot and dry through summer, with highs peaking around 86–87° in mid-July and holding there through August. Winters are mild but wet, with the coolest week of the year averaging just 51° in early January and the heaviest rainfall clustering around the third week of that same month. If you're avoiding heat, aim for April through May or October through November.