Concord Weather

April and May are the best months to visit Concord. In April 2025, the data shows average highs of 77.7F with a comfort score of 91 out of 100, nearly 13 hours of sunshine per day, and virtually no rain. May follows closely with highs of 78.6F, a comfort score of 90, and over 13 hours of daily sun. March is a strong third option: highs around 70F, a comfort score of 89, and only about a quarter inch of rain for the whole month. What makes spring so appealing here is that Concord heats up faster than the coast but avoids the inland furnace conditions of July. You get genuine warmth, low fog, and long evenings without the oppressive heat that arrives in summer. Wildflowers are out, Briones Regional Park is green and gorgeous, and the Delta breeze hasn't yet established its daily afternoon routine. If you can only visit once, aim for the last two weeks of April.

Concord gets genuinely hot. Summer highs consistently run in the mid-to-upper 80s Fahrenheit, with July and August averaging around 85F. That's roughly 20 degrees warmer than San Francisco on the same afternoon. The heat is dry rather than humid, which makes it more tolerable than it sounds on paper, but triple-digit days do happen during heat waves when the Delta breeze fails to arrive. What's interesting about the data is that comfort scores remain fairly high even during summer: July and August both scored 87 out of 100 over the 18-month observation period. That's partly because low humidity keeps the feels-like temperature reasonable, and partly because mornings are genuinely pleasant, averaging lows in the upper 50s. The practical advice: plan active outdoor time before noon. By 2 or 3 p.m. in July, Concord is hot in a way that coastal Bay Area residents find startling. For context on why inland East Bay heats up so much faster, why the Bay Area has so many microclimates explains the geography well.

Concord gets some fog, but far less than coastal or bay-adjacent cities. The 18-month data shows an average of just 1.7 hours of morning fog per day across all seasons. Compare that to, say, San Francisco or Daly City, and Concord is practically fog-free. Summer is when fog appears most reliably: June 2025 averaged 2.2 hours of morning fog per day, and November 2025 hit 4.3 hours, the foggiest month in the dataset. But by the time most people are up and moving, the fog has already burned off. Concord sits inland, east of the hills that capture and hold marine layer. The fog that does arrive typically creeps through the Carquinez Strait corridor rather than rolling in over the hills, so it's thinner and burns off faster. Morning fog here is more of a gentle atmospheric haze than the thick, visibility-killing blanket you see closer to the Golden Gate. For a deeper look at how that morning fog forms and disappears, why morning fog forms in the Bay Area is worth reading.

Concord's rainy season runs from October through March, following the Bay Area's classic Mediterranean pattern. The wettest months in the dataset are January 2025 (5.08 inches), November 2025 (4.79 inches), and November 2024 (4.47 inches). October is the transition month: you start getting some rain, comfort scores dip into the upper 70s, and afternoon highs drop into the low 60s. By December and January, expect cool, damp days, though it's worth noting that December 2024 scored a surprisingly decent 82 comfort score despite being winter, with 7.7 hours of sunshine per day on average. Rain here falls in storm systems, not constant drizzle. You'll get a few days of genuine soaking rain, then a stretch of clear, crisp weather with excellent visibility. Summer (June through September) is almost completely dry. May 2025 recorded zero precipitation. If you want to know when the worst months are, November and December sit at the bottom of the comfort rankings. For more detail on Bay Area rainfall patterns, the rainiest month in the Bay Area breaks it down by region.

Concord, Walnut Creek, and Martinez all sit in the same inland East Bay pocket, so they share the same basic climate: warmer and sunnier than the coast, with hotter summers and cooler winters than San Francisco. That said, there are real differences. Concord and Walnut Creek are relatively flat and urban, which amplifies heat through the urban heat island effect. Martinez sits closer to the Carquinez Strait and tends to see more wind, which can feel refreshing in summer but biting in winter. Alhambra Valley, just west of Martinez, runs cooler because of its exposure to marine air coming through the hills. Concord specifically is known as one of the hotter spots in Contra Costa County during heat events. Its low elevation (75 feet) and dense urban development trap heat effectively. On a 100-degree inland day, Concord may run 2 to 5 degrees warmer than Martinez and 5 to 8 degrees warmer than spots higher in the hills. For summer heat-seekers, that's a feature. For everyone else, it's something to account for.

Outdoor dining in Concord is genuinely pleasant for a long stretch of the year, roughly April through October. Spring is ideal: April highs around 77F, low wind, minimal fog, and evenings that stay warm enough to sit outside comfortably until 8 or 9 p.m. May and June are similarly good, with long days and comfortable temperatures. The challenge is summer afternoons. When Concord hits 85 to 90F in July and August, outdoor dining between noon and 4 p.m. requires shade and ideally some airflow. Most outdoor patios worth their salt account for this with misters, pergolas, or strategic orientation toward the afternoon breeze. Evenings save summer dining: temperatures drop quickly after sunset, and by 7 p.m. the air is usually pleasant. Winter outdoor dining is a different story. November and December average highs only in the mid-50s, and those months carry the worst comfort scores of the year (63 and 68 respectively). A heat lamp makes a big difference, but you're dressing like you mean it. The sweet spot is May through June and September through October, when Concord delivers the kind of warm, still evenings that make al fresco dining genuinely enjoyable.

September is one of Concord's best months, and the data backs this up clearly. Both September 2024 and September 2025 scored 87 comfort points out of 100. Highs in September run from the low to mid-70s on average, the summer humidity drops even further, and the afternoon Delta breeze mellows out compared to peak summer. It's warm, sunny, and genuinely comfortable in a way that July's intensity doesn't quite match. October is more of a transition: highs drop to the low 60s, comfort scores fall to the upper 70s, and rain starts arriving. So Concord does have a pleasant September extension, but it's more accurately described as a softened summer than a second one. The real story is that Concord doesn't have the dramatic "second summer" effect that some inland valleys experience, because it doesn't get the marine layer suppression that other areas do in summer. Why September is sometimes hotter than July in the Bay Area explains the mechanism behind this pattern for the broader region.

What to wear in Concord depends heavily on the time of year and time of day. In summer, dress for heat: lightweight, breathable fabrics, sun protection, and a hat are non-negotiable when afternoon highs regularly reach the mid-to-upper 80s. Sunscreen matters more here than at the coast because there's less cloud cover to filter UV exposure. Concord averages nearly 10 to 13 hours of sunshine per day from spring through summer. Bring a light layer for mornings, even in July, because lows can drop to the upper 50s. Spring and fall call for layers: a t-shirt plus a light jacket covers most situations, and you can adjust as temperatures climb through the afternoon. Winter visits require a proper jacket. November and December highs only reach the mid-50s, and morning fog plus low sun make it feel cooler than that. A medium-weight jacket and closed shoes are practical choices. One thing that catches visitors off guard: Concord doesn't have the coastal wind that makes San Francisco feel cold, but the afternoon breeze in spring and early summer can be brisk enough to cut through light fabrics. A packable windbreaker is always worth having. For dressing for Bay Area weather, the layering principle applies everywhere, including inland.

Concord is one of the sunnier parts of the Bay Area, and the numbers show it. The 18-month average is 9.6 hours of sunshine per day across all seasons. Peak sunshine arrives in May and June, when the data shows over 13 hours of sunshine daily. Even December and January, the depths of winter, average 6 to 7.7 hours per day. That's meaningfully more sun than you get on the San Francisco Peninsula or anywhere exposed to direct marine layer influence. The reason is straightforward geography: Concord sits inland, protected from the prevailing fog by the East Bay hills and the ridge systems running through Contra Costa County. Marine layer that smothers San Francisco by late afternoon has usually dissipated or stalled well before reaching Concord. Summer mornings do see some fog, around 1 to 2 hours on average, but it typically burns off before 10 a.m. The trade-off is heat: those same geographic features that block fog also trap warmth in summer. But if sunshine is your primary metric, Concord delivers it reliably. With 265 perfect days per year by the site's comfort algorithm, it scores among the most consistently pleasant destinations in the region.

November and December are the weakest months in Concord's weather calendar by a clear margin. November 2025 posted a comfort score of just 63 out of 100, the lowest in the 18-month dataset. November 2024 was similarly poor at 70. December 2025 scored 68. The combination driving those low scores: average highs only in the mid-50s, substantial rainfall (November 2025 saw nearly 5 inches), and the fewest sunshine hours of the year, around 6 hours per day. Morning fog runs longer in November, up to 4.3 hours per day in November 2025, and the afternoons never fully warm up the way they do in spring. January is similarly wet (5 inches of rain in January 2025) but actually scored a slightly better comfort rating of 74, partly because the rain came with some decent sunshine intervals. If you're visiting for the first time and want to see Concord at its best, November and December are the months to avoid. If you do visit in winter, plan for short-sleeve-under-a-jacket weather at best, and check the forecast closely. The Bay Area's four seasons has a good overview of what to expect region-wide.