Historical weather data, all-time temperature records, and monthly climate averages for Arroyo Grande, CA. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5th in Arroyo Grande typically feels like a gentle spring day, with average highs of 68° and lows around 45°. That said, the date has some range — it's hit as warm as 90° back in 1961 and dipped to a chilly 34° in 1999. There's about a 1-in-5 chance of rain today, but snow is essentially off the table.
Arroyo Grande's climate is mild by almost any measure, but the extremes are real. The all-time high of 113° on September 6, 2020 is a stark reminder of how brutal late-summer heat events can get along the Central Coast, while a record low of 17° in December 1990 shows the valley can freeze hard when conditions align. The wettest single day on record — 6.05 inches on January 9, 2023 — came during California's punishing atmospheric river season.
Arroyo Grande is remarkably temperate year-round, with monthly average highs ranging only from 63° in early January to 80° in late August — a spread that most of the country would envy. If you're chasing warmth, late August through early September is your window; if you want to avoid rain, stick to spring through fall, as the wettest stretch clusters around Christmas week at an average of 1.54 inches. It's one of those rare places where almost any month is worth visiting.