Pleasant Hill Weather

April and May are the standout months in Pleasant Hill. April averaged a high of 77.7F with a comfort score of 91 out of 100, and May was nearly as good at 78.6F with a score of 90. Both months have almost no rain, minimal morning fog (under an hour per day), and long sunny days pushing 13 hours. March is also excellent, hitting a 10.8-hour sunshine average and a comfort score of 89 despite still being early spring. What makes spring special here is the combination: warm enough to eat outside without a jacket at noon, cool enough that you sleep well at night. The surrounding hills are green, and the suburban streets come alive with outdoor patrons. If you can only visit once, late April is about as reliable as Bay Area weather gets.

Pleasant Hill runs genuinely warm in summer. June through August typically sees highs in the low-to-mid 80s F, with July and August averaging around 85F. That is a full 15 to 20 degrees warmer than San Francisco on any given summer afternoon. Unlike coastal towns where the marine layer keeps things perpetually cool, Pleasant Hill sits in the Contra Costa interior, sheltered from direct ocean influence. The tradeoff: occasional heat spikes, particularly in late July and early August, where temperatures can push into the low 90s during extended inland heat events. Evenings cool off nicely, with lows typically in the upper 50s, which makes for comfortable outdoor dining even in the heart of summer. September historically stays warm here, often warmer than June, which is one of the lesser-known quirks of Bay Area seasonality. September 2024 averaged a high of 82F with a comfort score of 87.

Winter in Pleasant Hill is mild by most standards but genuinely rainy. January is the wettest month, averaging over 5 inches of rain, and November and December each bring close to 5 inches as well. Daytime highs drop to the mid-to-upper 50s F, with lows around 40 to 45F. You won't get snow or hard freezes, but you will get stretches of grey, drizzly days, especially November through January. That said, the Bay Area's rainy season tends to arrive in discrete storm systems rather than persistent drizzle, so sunny windows between storms are common. December 2024 was a good example: despite being a winter month, it logged a comfort score of 82 and nearly 8 hours of daily sunshine, because the rain was concentrated in a few big storms rather than spread evenly across the month. If you visit in winter, pack rain gear but don't expect to be rained out every day.

Compared to coastal Bay Area towns, Pleasant Hill is relatively fog-light. Morning fog averages just 1.7 hours per day across the year, and during the warmest summer months it barely registers at 1 to 1.2 hours. The fog that does appear typically burns off well before noon. November is the foggiest month, averaging 4.3 hours of morning fog, driven more by overnight radiation fog in the inland valleys than the ocean marine layer. This is a meaningful distinction: coastal towns battle afternoon fog in summer, while Pleasant Hill deals mostly with morning ground fog in fall and winter. By midday on almost any day of the year, Pleasant Hill is clear and sunny. If you're trying to escape the summer fog that blankets much of the Bay Area, a Contra Costa suburb like Pleasant Hill is a reliable bet. The mechanics behind Bay Area fog formation explain why inland areas like this see so much less of it than the coast.

Pleasant Hill, Walnut Creek, and Concord share a lot of the same climate DNA. All three sit in the interior Contra Costa corridor, protected from the direct coastal marine layer, and all run significantly warmer and sunnier than the Bay's west-facing shores. The differences are subtle: Concord tends to run a couple of degrees warmer in summer due to its further inland position and can push into uncomfortable heat territory during strong inland heat events. Pleasant Hill sits slightly closer to the hills and tends to catch a bit more of the afternoon sea breeze funneling through the Carquinez Strait corridor. Walnut Creek is very similar to Pleasant Hill in both elevation and exposure. For practical purposes, if you're choosing between them for an outdoor meal or afternoon walk, the weather will be nearly identical. The real microclimate jumps happen when you cross the hills into places like Briones Regional Park, where elevation and terrain change the picture quickly.

Pleasant Hill is well suited for outdoor dining across a long season. April through October is the reliable window, with comfortable afternoon temperatures, minimal rain, and plentiful sunshine. The sweet spot for patio weather is May through June, when highs sit in the upper 70s, fog is minimal, and evenings cool pleasantly without getting cold. July and August are warm enough that a shady patio is preferable to full sun, but perfectly comfortable. September is arguably the best outdoor dining month of all: warm, dry, and with noticeably longer clear evenings than midsummer. September 2025 averaged a high of 72.3F with a comfort score of 87. The one thing to watch for is afternoon wind. Pleasant Hill sees occasional breezy afternoons in spring and early summer when the thermal gradient between the hot interior and the cool coast pulls marine air inland. It rarely makes outdoor seating unpleasant, but a light layer is smart for late dinners in May or June.

The data points to roughly 265 pleasant-weather days per year in Pleasant Hill, which is exceptional by Bay Area standards. Average daily sunshine runs 9.6 hours across the year. The sunniest months are May and June, each logging over 12 hours per day of sunshine, reflecting the long days and reliably dry conditions. Even in the heart of winter, Pleasant Hill manages 6 to 7 hours of sunshine per day on average. What's striking is how consistent the comfort scores are through summer: June, July, August, and September each landed at 87 out of 100, suggesting not just sunny days but genuinely comfortable ones. The low-comfort months are November and December, when scores dip into the 60s, driven by rain and reduced sunshine rather than extreme cold. For a suburban Bay Area town, Pleasant Hill punches well above its weight for sunshine.

The classic Bay Area advice applies here: layers, but less aggressively than you would need near the coast. In summer, a T-shirt and shorts work for midday, but bring a light layer for morning and evening. The temperature swing from a 57F morning low to an 85F afternoon high in July is real and catches visitors off guard. Sunscreen is non-negotiable. The inland sun in Pleasant Hill hits harder than the diffused coastal light, and there is no marine fog to take the edge off UV exposure. In spring and fall, add a medium-weight jacket for evenings. The layering logic that governs Bay Area dressing applies even here, though the range is more forgiving than in San Francisco. In winter, bring rain gear if there is any weather system in the forecast. A waterproof shell over a fleece is usually enough. Heavy parkas are overkill. Comfortable walking shoes handle the suburban terrain well, and if you're heading into the nearby hills, trail shoes are worth it.

The rainy season runs from roughly November through March, with January being the wettest month at around 5 inches. October is the transition month, with moderate rain returning after a completely dry summer. Pleasant Hill averages about 61 rainy days per year, concentrated heavily in that November-March window. The rain rarely falls as steady all-day events. More typically, storm systems roll through over two or three days, deliver a significant portion of the monthly total, then clear out. January 2025 brought 5.08 inches while December 2024 recorded only 0.71 inches. In practice, this means winter visitors will encounter storms but not constant grey skies. If a forecast shows no active storm system, winter days in Pleasant Hill can be remarkably bright. Summer is reliably dry. June 2024 and June 2025 both recorded zero rain, and May 2025 was also completely dry, typical for the inland Contra Costa area.

Pleasant Hill itself is fairly consistent, sitting at around 177 feet elevation in a relatively flat suburban grid. But step a few miles in any direction and the picture changes fast. Head west into Lafayette or through the tunnel toward Orinda and you're in areas that hold fog longer in summer. Head into Alhambra Valley and you're in a narrow valley with its own fog and frost patterns. Drive east toward Concord and temperatures tick up a few degrees as you move further from bay influence. Pleasant Hill sits in the comfortable middle of this range: warmer and sunnier than the coastal side of the hills, without reaching the peak heat of the furthest inland valleys. The Bay Area's microclimate geography is one of the more fascinating weather stories in North America, and Pleasant Hill represents the moderate interior zone that gets more sunshine than the average visitor expects.