Alameda Weather

April and May are the standout months for Alameda. Both averaged a comfort score of 89 out of 100 in 2025, with highs in the low 70s, lows in the low 50s, and virtually no rain. May 2025 recorded zero inches of precipitation with 12.7 hours of sunshine per day, which is about as close to perfect Bay Area weather as you will find. August is also excellent, typically landing around 89 comfort with highs near 77 degrees. The summer months benefit from the bay's moderating effect: Alameda stays a few degrees warmer than San Francisco and a few degrees cooler than the inland East Bay. If you want long, sunny days with pleasant temperatures and minimal fog, late spring is the answer. August delivers similar sunshine but with slightly shorter days and the occasional marine layer morning. Either way, you will have weather that is genuinely enjoyable rather than merely tolerable.

Alameda winters are mild by most standards but can feel damp and gray. January 2025 was the coldest month in the dataset, with an average high of just 59.9 degrees and an average low of 44.7. December 2025 was even gloomier, averaging only 6.4 hours of sunshine per day and dropping to a comfort score of 68, the lowest in the 18-month record. Lows rarely dip below the upper 30s, and frost is almost unheard of at 16 feet of elevation on a bay island. The bigger issue in winter is rain: January 2025 logged 6.22 inches, and November and December consistently see 3 to 5 inches. The cold here is the kind that seeps in rather than snaps, a combination of wet air, wind off the water, and cloud cover that never quite lifts. Pack a waterproof layer and plan for short daylight windows. For context on what drives these wet patterns, see the rainiest months in the Bay Area.

Yes, but Alameda is notably less foggy than San Francisco. The 18-month average is 2.1 hours of morning fog per day, which sounds significant but is spread across all months. Summer months like June and July see 2 to 3.6 hours of fog per morning on average, but it usually burns off by mid-morning. Alameda's position on the eastern side of the bay means it gets the tail end of the marine layer that rolls in through the Golden Gate and across the bay. San Francisco's fog arrives thick and persistent; by the time it reaches Alameda, it has already begun to thin. September is often the clearest month, with just 1.2 hours of morning fog in 2024. June 2025 was the foggiest on record in this dataset at 3.6 hours per morning. If you are planning an early outdoor activity and want to avoid the marine layer, late summer mornings work better than early summer. You can read more about why morning fog forms in the Bay Area.

Alameda sits on a flat island surrounded by open water, which makes it more exposed to bay winds than inland East Bay neighborhoods. The wind patterns here are driven by the same afternoon pressure gradient that pulls air in through the Golden Gate and across the bay each day, typically kicking up between noon and 4 p.m. in summer. On the waterfront and along the estuary, you will feel it more directly than you would a mile inland in Oakland. That said, Alameda is not San Francisco's windswept Sunset District. The hills of Oakland to the east provide some shelter, and the bay's surface here is calmer than the open bay near Treasure Island or the Bay Bridge. Wind comfort is baked into the overall 83 comfort score average, so it is manageable. The main takeaway: bring a windproof layer if you are planning time on the waterfront in the afternoon, particularly from June through August. Understanding why the Bay Area has so much wind helps explain why Alameda's breezes are both predictable and seasonal.

Layering is the right strategy year-round. Even in the warmest months, mornings start cool, often in the mid-50s, and the bay breeze makes waterfront areas feel cooler than the thermometer suggests. A light jacket or windbreaker is the most important item to have on hand from May through October. In summer, you can get away with shorts and a t-shirt by midday, but you will want to pull that layer back on by late afternoon. In winter and shoulder months (November through February), a waterproof outer layer matters more than warmth. The temperatures rarely demand a heavy winter coat, but persistent drizzle and damp air can make 55 degrees feel much colder than it sounds. Wear comfortable walking shoes that can handle wet pavement, since Alameda's streets and waterfront paths can be slick after rain. Sunscreen is worth applying even on overcast days, since UV exposure at this latitude is higher than most people expect. The dressing in layers guide for Bay Area weather covers this in more detail.

For most of the year, yes, with the right timing. From April through October, afternoon temperatures in Alameda regularly reach the mid-60s to mid-70s, which is comfortable for outdoor seating when the sun is out. April 2025 averaged a high of 70.7 degrees with a comfort score of 89, making it one of the best months for patios and outdoor tables. Summer is warm enough but the afternoon bay breeze can make shaded outdoor seating feel cool. A patio with some wind protection and afternoon sun is ideal. Lunch works better than dinner in summer: temperatures drop quickly after sunset, and evenings in the 50s can feel chilly if you are sitting still. In winter, outdoor dining becomes a matter of preference and clothing. December and January average highs only in the upper 50s, and rain is common. A heated patio with overhead cover makes winter outdoor dining viable, but it is not the same experience as a warm spring afternoon. The roughly 255 perfect days per year the data shows suggests that outdoor dining windows are genuinely plentiful here.

Alameda sits in an interesting microclimate position. It runs warmer than San Francisco but cooler than Oakland's inland neighborhoods like Fruitvale or Piedmont. The bay water surrounding the island acts as a thermal regulator, keeping summer highs from climbing into the 80s the way they can in Downtown Oakland or further inland. On a hot inland day when Walnut Creek is hitting 95 degrees, Alameda might be 72. Conversely, Alameda does not get the intense fog that suppresses summer temperatures in the Outer Sunset or Daly City. The result is a climate that threads the needle: sunnier than San Francisco, cooler than the East Bay interior. The 18-month average high of 67.9 degrees reflects this balance. Piedmont, which sits in the Oakland hills, experiences more pronounced temperature swings and clearer winter days but hotter summers. Alameda's island geography produces a relatively consistent, moderate climate that the Bay Area's famous microclimate variation only reinforces.

The rainy season runs from late October through March, with January as the wettest month on average. January 2025 logged 6.22 inches of rain, and November 2024 and 2025 both came in around 5 to 5.5 inches. October marks the transition: October 2024 dropped 4.84 inches after a dry summer, while October 2025 brought 3.7 inches. The rain here is classic Northern California winter rain, persistent and moderate rather than tropical downpour. You might go several days in a row with drizzle and overcast skies, then have a clear stretch for a week. Storms usually blow through in one to three days, often followed by beautiful, crisp, washed-out light on the bay. The dry season is genuinely dry: May 2025 recorded zero inches of rain, and June through August typically see only trace amounts. With roughly 79 rainy days per year, Alameda is wetter than many people expect but still significantly drier than most of the Pacific Northwest. Planning outdoor activities for the morning after a storm clears often rewards you with exceptional visibility across the bay.

Alameda averages 9.5 hours of sunshine per day across the full 18-month dataset, which is quite good for a Bay Area waterfront location. The peak comes in April and May, both hitting 12.7 hours per day in 2025. June and July also deliver strong sunshine, averaging around 11.5 hours even with morning fog factored in. The fog burns off reliably, so those morning marine layer hours rarely define the full day. The low point is winter: December averages around 6.4 to 7.9 hours of sunshine, and November drops to about 6.2 to 6.5 hours. Even in the cloudiest months, Alameda sees more sunshine than coastal San Francisco because the marine layer dissipates more completely over the eastern bay. The 255 perfect days per year figure in the data underscores that this is genuinely a sunny place despite the Bay Area's foggy reputation. Summer sunshine combined with bay views and the island's wide, flat streets makes Alameda an unusually pleasant place to be outdoors from late morning through early afternoon.

December and January are the toughest months. December 2025 recorded the lowest comfort score in the dataset at 68, with an average high of only 58 degrees, 6.4 hours of sunshine, and nearly 3 inches of rain. January 2025 was similarly difficult, with 6.22 inches of rain and a comfort score of 73. November also underperforms, consistently landing around 74 comfort with short days and significant rainfall. The challenge in these months is the combination of factors rather than any single extreme: it is not bitterly cold, but it is gray, damp, and the days are short. Winds off the bay can make the waterfront feel rawer than the temperature alone suggests. If you visit in winter, aim for the midday hours after any overnight rain has passed and before the next system moves in. Jack London Square nearby has covered and indoor options if the weather turns, which adds some flexibility to a winter day trip. The contrast with spring is striking: April's comfort score of 89 is 20 points above December's low.