Martinez Weather

March through May is the sweet spot for Martinez. March averaged a 90 comfort score in 2025, with highs around 71°F, nearly 11 hours of sunshine per day, and almost no rain. April and May follow closely, both hitting 89 comfort scores with highs pushing into the upper 70s and minimal fog. This is when Martinez really shines: warm enough for comfortable walking and outdoor dining, but not yet baking under summer heat. The waterfront is genuinely pleasant in spring, and the hills around town are green from winter rains. If you want reliable weather without crowds or heat, late April is a strong pick. Summer is also excellent, just warmer and occasionally hazy. The Bay Area has well-defined seasons, and spring is one of the better windows across the region for comfortable outdoor time.

Martinez runs warm in summer, noticeably warmer than bayside and coastal towns. June through August averages highs in the mid-to-upper 80s: June 2024 peaked at 88°F, July averaged 86°F, and August came in around 86°F as well. This is Contra Costa County inland heat, not the cool foggy summers you get in San Francisco or Oakland. Heat events are real here. The delta breezes from the Sacramento River help moderate temperatures somewhat, particularly in the afternoons, but during high-pressure spells Martinez can sit several degrees above what the rest of the Bay is experiencing. If you are visiting in July or August, plan outdoor activities for the morning. By early afternoon it is often too warm for sustained effort, though evenings cool off meaningfully. Compare this to Benicia just across the water, which tends to catch more wind and runs a bit cooler on the hottest days.

Yes, but less than you might expect given its location on the water. Martinez averages about 1.9 hours of morning fog per day across the year, which is modest by Bay Area standards. Fog is most persistent in November (averaging 4.8 hours per day) and October (3.8 hours), and again in June (2.2 hours). This pattern reflects two different fog regimes: the winter tule fog that forms inland on cold nights, and the summer marine layer that occasionally pushes up through the Carquinez Strait from the bay. Most summer days the fog burns off well before 9 a.m., leaving the rest of the day clear. If you want to understand the mechanics, why morning fog forms in the Bay Area has a solid breakdown. For Martinez specifically, the fog situation is manageable, and rarely ruins a full day.

Martinez gets roughly 63 rainy days per year, concentrated heavily in the November through March window. November is typically the wettest period, averaging around 5 inches across the two Novembers in the data set. January is the other peak month, with about 5.5 inches of rain in January 2025. By comparison, summer is essentially dry: June, July, and most of May recorded zero inches. The rain that does fall tends to arrive in systems, not drizzle, so you can have several dry days in a row even in winter followed by a genuine storm. December is interesting: despite being a winter month, it logged only 0.86 inches in 2024, showing how variable the season can be. The rainiest months in the Bay Area article covers the regional patterns well, but locally Martinez follows the typical inland East Bay rhythm: wet winters, bone-dry summers.

For most of the year, yes. From April through October, afternoon temperatures consistently run between 63°F and 88°F, which covers the full range from comfortable to warm. The waterfront areas and downtown have enough sun exposure that even a 65°F afternoon feels genuinely pleasant for sitting outside. Winter is more conditional. November and December bring average highs in the upper 50s, and with fog adding to the chill some mornings, an outdoor lunch requires a jacket. That said, the comfort scores for December 2024 and 2025 still hit 70-81 out of 100, which reflects how often clear, mild days appear even in the cool season. The real sweet spot for outdoor dining is March through May and then September through October, when the heat of peak summer has eased but the sun is still strong and days are long. This is a waterfront town built for being outside, and the weather mostly cooperates.

Martinez, Concord, and Pleasant Hill all share similar inland East Bay weather patterns, but there are meaningful differences. Martinez sits right on the Carquinez Strait, so it gets more marine influence than Concord, which sits farther inland and away from any water body. In practice, this means Concord runs hotter on summer afternoons and occasionally colder on winter nights, while Martinez is moderated slightly by proximity to the water. Pleasant Hill falls somewhere in between. None of these towns gets the persistent summer fog that defines San Francisco or the immediate coast. All three enjoy 260 or more sunny or partly sunny days a year. Concord regularly records summer highs 3 to 5 degrees above Martinez during heat events. Pleasant Hill is similar but slightly more sheltered from the delta breeze. For weather comfort, Martinez has a small edge in summer due to that afternoon breeze off the strait, and the overall microclimate picture is explained well in why the Bay Area has so many microclimates.

About 264 days per year qualify as perfect or near-perfect weather days in Martinez, based on the 18-month observation period. The sunshine data backs this up: average sunshine across the year is 9.5 hours per day, with peak months in April, May, and June reaching 12 to 13 hours. Even the winter months are not as gloomy as the fog reputation might suggest. December averaged 6 to 7.5 hours of sunshine per day across the two years in the data set. November is the weakest month at around 5.5 hours, but even that is reasonable. The sunny, warm months run long here, from roughly April through October. This is one of the underrated aspects of Contra Costa County towns like Martinez: they sit just far enough inland to escape persistent coastal overcast, but close enough to the bay to avoid the extreme heat of the Central Valley.

The right layering strategy depends heavily on the time of year. In summer, light clothing works for midday, but a light layer for mornings and evenings is smart, since temperatures can drop into the upper 50s overnight even when afternoons hit the mid-80s. In spring and fall, a medium jacket covers most situations. The temperature swing between morning and afternoon can be 20 to 25 degrees, so wearing something you can peel off matters. In winter, a proper jacket and layers are needed for morning outings, especially if there is fog. The bay waterfront can feel colder than the ambient temperature due to moisture in the air. Sunscreen is relevant year-round here: with 9.5 average sunshine hours per day and clear skies dominant, UV exposure is real even on mild days. The general Bay Area advice about dressing in layers applies to Martinez, though you can get away with slightly less extreme layering than the coast demands.

Wind in Martinez is real but mostly moderate. The town sits at the mouth of the Carquinez Strait, a natural wind corridor that funnels air between the Coast Ranges as pressure differences between the bay and the Central Valley drive afternoon breezes. This is the same system that makes the Carquinez Strait a popular sailing destination. In practical terms, afternoon winds in summer can make the waterfront feel noticeably cooler than the thermometer suggests, which is actually a feature: it takes the edge off 85°F afternoons. In winter, the same winds add a bite to overcast days that makes mid-50s feel colder than expected. The comfort scores reflect this well. The Bay Area wind patterns are part of a larger pressure system detailed in why the Bay Area has so much wind. For Martinez specifically, the wind is rarely extreme, and on most days it is a pleasant counterweight to inland heat rather than a nuisance.

Martinez winters are mild by most standards, just not beach-weather mild. Average lows in December and January drop to the low-to-mid 40s, and average highs run in the upper 50s to low 60s. Frost is uncommon at 16 feet of elevation near water, though cold nights do happen. The comfort scores for winter months are telling: December 2024 scored 81 out of 100 and March 2025 hit 90, which shows how quickly conditions improve once the rainy season starts to ease. The worst months in the data set are November and December 2025, both scoring in the 63-70 range, driven by a combination of fog, rain, and short days rather than severe cold. So yes, winter in Martinez is worth visiting if your expectations are set correctly. Expect occasional rain, some foggy mornings, and plenty of clear, crisp afternoons. The Alhambra Valley nearby offers a similar inland winter climate for comparison.