Historical weather data, all-time temperature records, and monthly climate averages for American Canyon, CA. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5th in American Canyon typically lands in pleasant spring territory, with average highs of 68° and lows of 44°. History shows the date can swing wild though — from a scorching 86° back in 1957 to a hard freeze at 31° in 1918. There's a 30% chance of rain today, so a jacket isn't a bad idea.
American Canyon has seen some genuinely extreme weather over its 133 years of records. The all-time high of 114° hit on September 6, 2022 — a reminder that late-summer heat here is no joke — while the coldest ever recorded was 14° on December 22, 1990. Snow is rare but not mythical; 2.5 inches fell on a January day in 1907.
American Canyon runs warm and dry from June through October, with highs in the low 80s peaking mid-July and holding strong through September. If you're cold-averse, skip January — highs average just 56° and late December is the wettest stretch of the year, averaging over an inch of rain in a single week. Spring and fall offer the sweet spot: mild temps in the 65–77° range with fading rain chances.