Historical weather data, all-time temperature records, and monthly climate averages for Discovery Bay, CA. Explore typical weather conditions by week for trip planning, and see how today compares to the historical record.
April 5th in Discovery Bay typically lands right in that sweet spot of spring — average highs of 71° with just a 1-in-5 chance of rain. The date has seen a wide swing over the years, from a chilly 39° low back in 1955 all the way up to an 88° scorcher in 1957.
Discovery Bay plays for keeps when it comes to extremes — the thermometer has hit 112° in June 1961 and cratered to 17° the day after Christmas in 1990. That 95-degree spread between all-time records tells you this is a place that earns its Delta reputation.
Discovery Bay runs hot and dry through summer, with late July highs averaging 95° and a long stretch of 88°+ weather from June through September. Winters are mild but wet, with the soggiest stretch arriving in mid-February and highs dipping to the mid-50s in January and December. If you're planning a visit, May through early June offers the sweet spot — warm days around 80° before the real heat sets in.