San Leandro Weather

August and September are the standouts. Both months averaged a comfort score of 88/100 in recent data, with highs in the mid-70s, lows in the mid-50s, and almost no rain. August averages just 0.07 inches of precipitation, and September often feels even sunnier as the morning fog begins to ease up. May is a close third, with highs around 68°F, 12.6 hours of sunshine per day, and virtually zero rain in 2025. The broader sweet spot runs from late April through October, when San Leandro reliably delivers warm afternoons and clear skies. If you have to pick a single week, the last two weeks of September tend to offer the warmest, least foggy conditions of the year. The marine layer is still retreating and inland heat has not quite faded yet, which creates that classic East Bay fall magic. For more on the Bay Area's seasonal patterns, there is a lot going on underneath what looks like simple "summer is best" advice.

Warm, but not punishingly hot. Summer highs in San Leandro typically land between 72 and 76°F, with lows in the mid-50s. July 2024 averaged a high of 72.6°F with a low of 56.1°F, and August 2024 came in at 74.6°F high, 56.3°F low. That is noticeably warmer than San Francisco, which regularly sits 10 to 15 degrees cooler on summer afternoons thanks to direct bay wind exposure. San Leandro's position in the inner East Bay gives it enough shelter from the marine layer to warm up pleasantly without the triple-digit heat events you see further inland in places like Livermore or Brentwood. Heat spikes do occur occasionally when offshore flow pushes temperatures into the low 80s, but they rarely last more than a day or two. Most summer afternoons feel genuinely comfortable for outdoor dining, walking, or sitting in a park, which is reflected in those consistently high comfort scores. June 2024 hit 74.6°F highs with a comfort score of 87, which gives you a sense of how livable the season is.

The rainy season runs from November through March, and it is real but not relentless. November averages around 5.2 to 5.4 inches of rain per month in wetter years, January can hit 5.5 inches, and the whole season tallies roughly 79 rainy days annually. That said, rain here comes in storm systems with dry stretches in between, not the gray all-day drizzle of places like Seattle. December 2024 was actually surprisingly pleasant: only 1.04 inches of rain and a comfort score of 82, which is higher than many people expect from a winter month. February tends to start clearing out, and by March the sun returns in force with 10-plus hours of sunshine and comfort scores back in the mid-80s. If you want to understand what drives those winter deluges, the atmospheric rivers that hit the Bay Area are usually the culprit. The rest of the year is genuinely dry: May through September averages less than a third of an inch of total precipitation combined.

Yes, but less of it than you might expect, and it clears faster than coastal spots. The data shows about 2 to 2.5 hours of morning fog per day through most summer months, which is enough to keep early mornings cool and hazy but not enough to ruin a day. By late morning most of it has burned off and the afternoon typically comes in sunny and warm. Compare that to neighborhoods in San Francisco or the coastal hills of Marin, where fog can hang around until 1 or 2 pm. San Leandro's inland position, even though it is technically on the bay, means the marine layer has already thinned considerably by the time it reaches this far east. June 2025 was the foggiest recent summer month, averaging 3.6 hours of morning fog, but even then the sunshine total for the month was 11.4 hours per day. For a deeper look at why fog behaves so differently across the Bay Area, this explainer on morning fog patterns covers the mechanics well.

San Leandro sits in a middle ground between waterfront Alameda and more exposed Hayward. Alameda, being a flat island directly on the bay, picks up more wind and fog from the marine layer pushing through the Golden Gate corridor. San Leandro has a touch more topographic shelter and tends to run a degree or two warmer on summer afternoons. Hayward is a close neighbor to the south with very similar temperature patterns, though the hills above Hayward create some local variations. The bigger differentiator is elevation: San Leandro proper sits at about 69 feet, which is low enough to stay in the warm zone but not so flat and exposed that bay winds dominate. Anthony Chabot Regional Park, which sits in the hills just east of San Leandro, runs 5 to 10 degrees cooler on summer afternoons and sees more fog persistence, a good reminder of how quickly the microclimate shifts as you gain elevation. San Leandro's 83/100 average comfort score reflects a genuinely favorable position in the East Bay's microclimate patchwork.

For much of the year, yes. The data supports around 255 perfect days annually, which works out to roughly five comfortable days per week on average. Spring and fall are the peak seasons for sitting outside: April averages highs of 68°F with 12.6 hours of sunshine, and the comfort score sits at 87. September and October remain strong, with highs in the 60s to low 70s and dry, clear afternoons. Summer is generally fine for outdoor dining in the afternoon once any morning fog has cleared, though evenings cool quickly as the marine air pushes back in. A light jacket is smart to keep on hand after 7 pm from June through August. Winter outdoor dining is possible on the many dry days between storms, but December and January drop into the low-to-mid 70s in terms of comfort scores, and you will feel it in evenings that can dip below 45°F. The rule of thumb: if you are visiting between April and October, assume you can eat outside without much worry.

The standard Bay Area layering approach applies, but San Leandro leans slightly warmer than places people usually think to layer for. In summer, light clothing works fine for afternoons, but bring a medium-weight layer for evenings and any morning fog periods. A light fleece or zip-up is more practical than a heavy jacket from May through October. In spring and fall, the temperature swing between a 52°F morning and a 68°F afternoon is real, so layers you can add and remove make sense. Winter visits call for a proper rain jacket and something warmer for evenings, when temperatures regularly dip into the low 40s. Sun protection is worth thinking about year-round: even on hazy days, San Leandro averages close to 10 hours of daylight sunshine at its peak, and UV exposure does not disappear with thin overcast. Comfortable walking shoes handle most of what the town offers day to day, though if you are heading up toward Castro Valley or the regional parks in the hills, something with a bit more grip is useful in wet season.

San Leandro is moderately affected by the same pressure-driven afternoon winds that push through the Bay Area every summer, but it is more sheltered than exposed bay-front spots or ridge-top locations. The afternoon sea breeze typically picks up between noon and 3 pm and can run 10 to 15 mph on warm days, which provides cooling without being disruptive. Because San Leandro sits slightly inland from the open bay, it does not get the consistent stiff winds that places like the Berkeley Marina or Coyote Hills see. The East Bay hills to the east block some of the offshore flow as well. Wind is more noticeable in spring, when temperature gradients between the cold Pacific and the warming interior are sharpest. By summer, the pattern is predictable: calm mornings, a building afternoon breeze, and quiet evenings. Understanding why the Bay Area gets so much wind helps put San Leandro's conditions in context. It is windy enough to feel pleasant on a hot day, not so windy that it creates problems.

Mild by most standards, but cool enough to notice. Average lows in December and January sit around 40 to 46°F, and highs typically land in the upper 50s. The coldest recent month in the dataset was December 2024, with a low average of 40.4°F. Frost is rare at this elevation and location, though it can happen on clear, calm nights in January. What most visitors feel in winter is a damp chill rather than sharp cold: when fog and rain combine, 50°F can feel colder than it reads. The good news is that San Leandro rarely sees extended gray stretches. Even in January, when rainfall peaked at 5.55 inches, the sunshine total was still 6.6 hours per day on average. There are regularly beautiful, clear winter days with highs in the low 60s and excellent visibility. The comfort scores for December and January drop to around 70 to 82, which reflects the rain risk more than genuinely uncomfortable cold. A decent jacket and waterproof layer get you through the worst of it.

San Leandro is a good example of the inner East Bay sweet spot: warm enough to escape the coast's fog and chill, cool enough to avoid the heat extremes of the far inland valleys. The Bay Area is famous for its dense patchwork of microclimates, and San Leandro's 69-foot elevation and east-bay position put it in a favorable zone. On a day when San Francisco is sitting under a thick marine layer at 58°F, San Leandro might be clear and 72°F. On the same day, Brentwood or Livermore could be pushing 95°F. San Leandro threads the needle more often than not, which explains that 83/100 average comfort score over 18 months of observations. The surrounding area reinforces this: Fruitvale to the north and Hayward to the south follow similar patterns, while the hills and parks above town shift into a noticeably cooler and foggier microclimate. For anyone trying to find reliably good weather in the Bay Area without trekking far, San Leandro is a solid default.