Historical weather data, all-time temperature records, and monthly climate averages for Suisun, CA. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 4th in Suisun typically lands in pleasant spring territory, with an average high of 69° and a low of 45°. The date has seen some wild swings, though — from a scorching 89° in 1985 to a bitter 37° low just one year later in 1986. Rain is unlikely but not impossible, with only a 16% chance of any precipitation.
Suisun plays for keeps when the weather gets extreme — the all-time high of 114° in July 2006 puts it firmly in Central Valley heat territory, while a Christmas Day low of 15° in 2011 proves it can bite in winter too. Even rainfall has its dramatic moments, with 6.1 inches falling in a single October day in 2021.
Summer is long and hot here, with highs hovering around 89-90° from early July through September — peak warmth lands the week of July 9-15. If you're cold-averse, avoid January, when highs only reach the mid-50s. The wettest stretch comes in mid-February, averaging 1.29 inches of precipitation for the week.