San Ramon Weather
Town • San Francisco Bay Area
San Ramon spreads across the southern San Ramon Valley and east into the newer Dougherty Valley. It reaches from the Las Trampas foothills on the west to grazed ridgelines on the east. Its office center at Bishop Ranch takes its name from a ranch begun in 1911 that was known as the largest single Bartlett pear orchard in the world. The Iron Horse Regional Trail runs north and south through the city, and Bollinger Canyon Road leads west into Las Trampas Regional Wilderness.
Plan your week
10-Day Forecast
Hour by hour
Hourly Forecast
Current Conditions
Comfort Breakdown
San Ramon weather today and through the year
It's 52°F at San Ramon right now (feels like 49°F), with 5 mph wind and a comfort score of 76. Monday's forecast high at San Ramon is 56°F, 8°F below the mid November normal of 64°F. The best window today is 8 AM to 11 AM, at about 55°F with a 9 mph wind (comfort 57).
July is the warmest month at San Ramon, with an average high of 86°F. December is the coldest, with an average low of 40°F. January is the wettest month (4.3 in.), out of about 21.3 in. a year. By typical temperature, wind, cloud, humidity, and rain odds, the most comfortable months at San Ramon are September, June, and August. The best hours are usually 10 AM to 1 PM in September, 11 AM to 2 PM in June, and 10 AM to 1 PM in August.
San Ramon shares Danville's basic setup. The Las Trampas high country, with Rocky Ridge topping 2,000 feet, blocks most of the bay's marine air to the west, so summer afternoons here are hot. San Ramon sits closer than Danville to the canyons and the Dublin pass where ocean air leaks in, though. It gets more summer morning low cloud and a stronger afternoon breeze than its neighbor.
Forecast updated November 15, 2026 at 4:00 AM PST. Climate figures come from NOAA 1991-2020 normals. Hourly patterns come from NOAA's HRRR hourly analysis from September 2014 to April 2026.
What to expect at San Ramon in the next few days
No active National Weather Service alerts for this location.
Best time to go
The best window today is 8 AM to 11 AM, at about 55°F with a 9 mph wind (comfort 57).
Best day this week
Of the next 7 days, Friday looks best for San Ramon, with a 59°F high and midday comfort near 77. Thursday looks weakest (49).
Rain
Next good chance of rain: today (81%, about 0.22 in.).
Live weather map
Weather around San Ramon right now
Overcast and 52° at San Ramon right now.
About the live weather map for San Ramon
The map centers on San Ramon and stacks fog, satellite clouds, and precipitation radar on one view. Clouds come from the GOES-West satellite and rain from NOAA radar, and both show current conditions. Fog comes from our HRRR-based fog model, and the slider steps through its forecast for the next 12 hours.
Dots mark nearby places with their current temperature, colored by comfort score. Use the layer buttons to turn any layer off, or open the full map for every destination in the region.
Nearby Temperature Comparison
Conditions at nearby San Francisco Bay Area destinations
Tip: Bay Area temperatures can change by 20 to 30°F over a short distance because of microclimates.
San Ramon vs nearby places
Typical summer conditions compared with San Ramon, from the same NOAA HRRR hourly record. The list shows the closest places, then nearby places whose climate differs the most.
| Place | Distance | Summer afternoons | Morning fog | Afternoon wind | Compared with San Ramon |
|---|---|---|---|---|---|
| Danville | 3.1 mi | +4°F | 3% | 8 mph | less summer morning fog (3% vs 25% of morning hours) and about 4°F warmer on summer afternoons |
| Las Trampas Regional Wilderness | 3.9 mi | -3°F | 19% | 11 mph | 1,206 ft higher |
| Dublin | 5.8 mi | +2°F | 7% | 11 mph | less summer morning fog (7% vs 25% of morning hours) |
| Coyote Hills Regional Park | 16.8 mi | -18°F | 21% | 14 mph | about 18°F cooler on summer afternoons and windier summer afternoons (14 vs 11 mph) |
| Downtown San Francisco | 22.9 mi | -19°F | 27% | 10 mph | about 19°F cooler on summer afternoons |
| Alcatraz Island | 24.5 mi | -22°F | 34% | 19 mph | about 22°F cooler on summer afternoons and windier summer afternoons (19 vs 11 mph) |
Places with a climate like San Ramon's
- Mission Peak Regional Preserve (19 mi away): nearly the same temperatures every month
- Napa (40 mi away): similar temperatures through the year
- Sonoma (44 mi away): similar temperatures through the year
Climate Dashboard
Current conditions vs. NOAA normals and recent destination baseline
What the San Ramon climate comparisons mean
These cards compare recent conditions at San Ramon with the available local baseline. Temperature and year-to-date rainfall use long-term normals when available. Fog, sunshine, wind, and comfort use the matching recent or modeled baseline identified on each card.
Positive and negative differences describe how San Ramon departs from its own usual pattern. They should not be read as a direct comparison with another city or as a forecast beyond the period shown.
San Ramon weather by month
July is the warmest month at San Ramon, with an average high of 86°F. December is the coldest, with an average low of 40°F. January is the wettest month (4.3 in.), out of about 21.3 in. a year. Morning fog peaks in July, when fog or low cloud covers 27% of the hours from 6 to 10 AM. July has the clearest middays, with clouds covering about 6% of the sky from 11 AM to 3 PM.
By typical temperature, wind, cloud, humidity, and rain odds, the most comfortable months at San Ramon are September, June, and August. The best hours are usually 10 AM to 1 PM in September, 11 AM to 2 PM in June, and 10 AM to 1 PM in August.
| Month | Avg high | Avg low | Rain | Rainy days | Morning fog | Midday cloud | Afternoon wind | Daylight | Comfort |
|---|---|---|---|---|---|---|---|---|---|
| Jan | 56°F | 40°F | 4.3 in | 9 | 16% | 32% | 6 mph | 9.8 h | 57 |
| Feb | 60°F | 42°F | 4.0 in | 8 | 10% | 25% | 8 mph | 10.7 h | 61 |
| Mar | 64°F | 44°F | 3.3 in | 7 | 12% | 30% | 8 mph | 11.9 h | 65 |
| Apr | 68°F | 46°F | 1.5 in | 5 | 13% | 22% | 9 mph | 13.2 h | 74 |
| May | 74°F | 50°F | 0.7 in | 3 | 19% | 19% | 11 mph | 14.2 h | 78 |
| Jun | 81°F | 54°F | 0.1 in | 2 | 22% | 8% | 11 mph | 14.8 h | 88 |
| Jul | 86°F | 57°F | 0.0 in | 0 | 27% | 6% | 11 mph | 14.5 h | 85 |
| Aug | 85°F | 58°F | 0.0 in | 1 | 25% | 7% | 10 mph | 13.6 h | 86 |
| Sep | 84°F | 56°F | 0.1 in | 1 | 18% | 11% | 9 mph | 12.3 h | 89 |
| Oct | 76°F | 51°F | 1.0 in | 4 | 11% | 14% | 7 mph | 11.1 h | 85 |
| Nov | 64°F | 44°F | 2.1 in | 6 | 11% | 22% | 6 mph | 10.0 h | 76 |
| Dec | 56°F | 40°F | 4.3 in | 9 | 20% | 33% | 6 mph | 9.6 h | 55 |
Morning fog is the share of hours from 6 to 10 AM with fog or low cloud. Midday cloud is the average from 11 AM to 3 PM, and afternoon wind is the average from 1 to 5 PM. The highlighted rows are the most comfortable months.
In summer, recent daily NOAA readings at San Ramon average about 4°F cooler than the 1991-2020 normals. The normals average over a wider area that also covers nearby terrain. Read the monthly highs as a rough range, and use the recent months below for what San Ramon has actually seen.
What makes San Ramon's weather different
When the fog burns off
10 AMwhen July fog usually thins (35% foggy at 8 AM)
Fog or low cloud covers San Ramon in 35% of 8 AM hours in July, the foggiest month. It usually thins to a third of that by 10 AM. February mornings are the least foggy (10%).
When the wind picks up
1 PMwhen afternoon wind builds, February–October
From February through October, wind at San Ramon typically builds after 1 PM. In May it peaks around 5 PM, averaging 12 mph with 14% of those hours windy, while mornings average 7 mph.
Elevation
−3°Fsummer afternoons at Las Trampas Regional Wilderness, 1,206 ft up
Las Trampas Regional Wilderness sits 1,206 ft higher, 3.9 miles away. Its summer highs average 3°F cooler and its winter lows 1°F milder than San Ramon.
Daylight
9.6–14.8 hof daylight, Dec to Jun
Days at San Ramon range from about 9.6 hours in December to 14.8 hours in June. In mid-June the sun sets around 8:32 PM, and in mid-December around 4:56 PM.
Seasons at San Ramon
- Warm seasonJun 27 – Sep 26 · highs 82°F+
The warm season lasts about 3 months, from Jun 27 to Sep 26, when the average high is 82°F or warmer. Highs peak around Jul 8 at about 86°F.
- Hot afternoonsJul 7 – Aug 27 · highs 85°F+
Average highs reach 85°F or more from Jul 7 to Aug 27.
- Cool seasonNov 28 – Feb 27 · highs 62°F or lower
The cool season runs from Nov 28 to Feb 27, when the average high is 62°F or lower. The coldest nights come around Dec 8, with an average low near 40°F.
- Rainy seasonNov 16 – Apr 2 · 80% of the year's rain
The rainy season runs from Nov 16 to Apr 2, when a day has at least a 20% chance of measurable rain. That stretch brings 80% of the year's rain.
The dark line marks today. Season dates come from the smoothed daily NOAA 1991-2020 normals. Counting from Oct. 1, a typical year has its first inch of rain by Nov 1 and half of its annual total by Jan 24.
Days per year and extremes (Nov 1, 2024 to Oct 31, 2026)
This record runs from Nov 1, 2024 to Oct 31, 2026. Over this record, San Ramon averaged 25 days a year at 90°F or hotter and 2 nights a year at or below freezing. It averaged 16 days a year with at least half an inch of rain and 1 afternoon with wind of 20 mph or more at 2 PM. About 82 mornings a year had 3 or more hours of fog or low cloud.
In the same record, the hottest day was Sep 9, 2026 (100°F) and the coldest night was Feb 10, 2025 (32°F). The wettest day was Feb 14, 2025 (1.75 in.), and the strongest 2 PM gust was 40 mph on Mar 12, 2025.
- 25days at 90°F or hotter
- 2nights at or below freezing
- 16days with ½ in. of rain or more
- 1afternoon with 20+ mph wind
- 82mornings with 3+ hours of fog or low cloud
- Hottest day100°FSep 9, 2026
- Coldest night32°FFeb 10, 2025
- Wettest day1.75 inFeb 14, 2025
- Strongest 2 PM gust40 mphMar 12, 2025
What shapes San Ramon's weather
What sets San Ramon apart is its spread. The city runs from the valley floor along I-680 east into the Dougherty Valley, whose neighborhoods climb toward open ridgelines. Those slopes take full sun and more wind. On the west side, canyon mouths such as Bollinger and Crow canyons let cold air slide down onto the valley floor on clear nights.
The south end of the valley opens toward Dublin and the Tri-Valley, so San Ramon's air is tied to the Livermore Valley as well as to Contra Costa. The Air District notes that eastern Alameda County has the Bay Area's highest ozone levels on hot summer afternoons. Check the air on smoggy or smoky days before hard exercise.
Tips for visiting San Ramon
Know where to cool off
During extreme heat the city opens the Alcosta Senior and Community Center, the San Ramon Community Center, and the Dougherty Station Community Arts Center as cooling sites.
Let kids run through the fountains
Participatory fountains at San Ramon Central Park and Rancho San Ramon Park are a free way to cool down on hot days.
Give cattle space on the ridge trails
Cattle graze near the Tassajara Ridge and Dougherty Valley Ridge trails. Keep dogs leashed and never walk between a cow and her calf.
Carry water into Las Trampas
The Park District says the water supply at Las Trampas is inconsistent and may be unavailable at any time.
Bike the Iron Horse Trail
The paved regional trail links Concord and Pleasanton on the old Southern Pacific right-of-way and is open to bikes, walkers, horses, and dogs.
Spot the Rancho San Ramon boundary oak
A leaning live oak on the hillside, visible from Bollinger Canyon and Anza Court, marked a corner of José Amador's Rancho San Ramon in 1833.
San Ramon through the seasons
- Spring (March–May)
- Spring turns the ridges green and brings the best hiking weather on the Dougherty and Tassajara ridge trails, before the grass dries.
- Summer (June–August)
- Summer afternoons are hot and sunny. The city may extend cooling-center hours when temperatures hit 100°F or more for three or more days in a row.
- Fall (September–November)
- August through November is calving season on the grazed ridge trails, and fire danger stays high until the first rain.
- Winter (December–February)
- Winter brings most of the year's rain. Between storms, clear nights can leave frost in low spots near the canyon mouths, and afternoons stay cool.
Activities and the weather that matters
- Ridge hiking: Spring and cool fall mornings are ideal on the exposed Dougherty Valley and Tassajara ridge trails. Summer afternoons there have little shade.
- Biking the Iron Horse Trail: The trail is flat and paved. Summer rides are best before mid-morning.
- Hiking Las Trampas: The Bollinger Canyon trailhead is the gateway to Rocky Ridge. Go on cool, clear days and bring all your water.
Official sources and current conditions
- City of San Ramon: Cooling centers
- City of San Ramon: Trails
- East Bay Regional Park District: Las Trampas Regional Wilderness
- Bay Area Air District: Alameda County air quality
Numbers on this page come from NOAA data. The text draws on the official sources linked above.
Historical Climate Data
Long-term weather patterns and climate data
Data sources: Recent temperatures come from NOAA URMA and recent precipitation from NOAA Stage IV. Fog, cloud, wind, humidity, and sunshine come from NOAA HRRR, and long-term baselines from NOAA 1991-2020 climate normals.
Climate Overview
Based on NOAA 30-year temperature/rain normals (1991-2020) with recent fog/sun baseline
🌟 Best Months to Visit
⚠️ Challenging Months
Monthly Breakdown
| Month | Comfort | High/Low | ☀️ Sun | 🌫️ Fog | 💧 Rain | Perfect |
|---|---|---|---|---|---|---|
| November 2024 | 82 | 62.3° / 44° | 6.7h | 2d | 2.71" | 22 |
| December 2024 | 71 | 59° / 43.5° | 5h | 8d | 6.12" | 12 |
| January 2025 | 84 | 59.6° / 39.2° | 7h | 1d | 0.19" | 22 |
| February 2025 | 78 | 60.2° / 42.2° | 6.6h | 3d | 6.57" | 14 |
| March 2025 | 84 | 61.7° / 43.9° | 8.6h | 1d | 2.3" | 21 |
| April 2025 | 91 | 67.9° / 46.8° | 9.9h | 1d | 0.57" | 26 |
| May 2025 | 92 | 73.9° / 50.5° | 12h | 2d | 0.22" | 30 |
| June 2025 | 94 | 76.2° / 52° | 12.2h | 4d | 0" | 30 |
| July 2025 | 91 | 77.4° / 55.1° | 11.7h | 7d | 0" | 30 |
| August 2025 | 91 | 83.4° / 57.1° | 11.3h | 3d | 0" | 29 |
| September 2025 | 90 | 80.3° / 59.7° | 9.7h | 6d | 0.31" | 28 |
| October 2025 | 89 | 72.4° / 52.5° | 8.1h | 2d | 1.96" | 26 |
| November 2025 | 79 | 64.2° / 47.9° | 6.4h | 8d | 3.71" | 13 |
| December 2025 | 68 | 56.2° / 43.4° | 5.2h | 13d | 4.05" | 4 |
| January 2026 | 79 | 60.3° / 42.2° | 6.9h | 3d | 3.58" | 20 |
| February 2026 | 79 | 63.2° / 44° | 6.6h | 6d | 4.57" | 18 |
| March 2026 | 94 | 76.7° / 50.3° | 9.9h | 1d | 0.03" | 30 |
| April 2026 | 86 | 67.3° / 48.5° | 9.4h | 2d | 4.47" | 23 |
| May 2026 | 91 | 72.5° / 51.3° | 11.5h | 4d | 0.68" | 28 |
| June 2026 | 93 | 78.2° / 54.6° | 12.2h | 3d | 0" | 30 |
| July 2026 | 92 | 80.8° / 56.6° | 11.6h | 3d | 0" | 29 |
| August 2026 | 92 | 83° / 57° | 11.1h | 5d | 0" | 31 |
| September 2026 | 93 | 79° / 55.8° | 10.1h | 4d | 0.13" | 28 |
| October 2026 | 87 | 77.9° / 54.1° | 8.2h | 1d | 0.32" | 26 |
Climate Trends
Average Temperature by Month
About the San Ramon climate charts
The temperature chart compares average monthly highs and lows at San Ramon, showing both the seasonal cycle and the typical day-to-night range. The comfort chart summarizes how often the combined weather pattern is favorable rather than judging temperature alone.
Precipitation shows the total recorded or modeled rainfall for each month at San Ramon. Sunshine compares average bright-sky hours with the daylight available, while fog shows the average number of morning fog or low-cloud hours per day. Switch between the chart tabs to compare the same months across each measure.
Hourly Temperature, Fog, Wind, Cloud Cover, and Solar Radiation Patterns
Average local hour by month from 2014-09-30 to 2026-04-30
- Temperature: At San Ramon, the warmest typical hour is 3 PM in August (83°F). The coldest is 7 AM in December (43°F).
- Fog: Fog or low cloud covers San Ramon in 35% of 8 AM hours in July, the foggiest month. It usually thins to a third of that by 10 AM. February mornings are the least foggy (10%).
- Wind: From February through October, wind at San Ramon typically builds after 1 PM. In May it peaks around 5 PM, averaging 12 mph with 14% of those hours windy, while mornings average 7 mph.
- Cloud Cover: July middays are the clearest at San Ramon (6% average cloud cover), and December middays are the cloudiest (33%).
- Solar Radiation: The strongest typical sun at San Ramon comes at 1 PM in June, averaging 999 W/m².
How to read the hourly heatmaps for San Ramon
This heatmap shows how average temperature at San Ramon changes by hour and month. Read left to right for the seasons and top to bottom for the time of day. Warmer colors mark the usual afternoon peaks, and cooler colors show overnight and winter lows.
This heatmap shows when fog or low cloud is most likely at San Ramon. Darker cells mark the months and hours when fog has been most common. They help separate overnight or morning fog from cloud that tends to linger into the afternoon.
This heatmap shows the typical hourly wind pattern at San Ramon through the year. It makes recurring afternoon wind, calmer overnight periods, and seasonal changes easier to compare than a single daily wind value.
This heatmap shows average cloud cover at San Ramon for every month and hour. Use it to see whether cloudiness is mainly an overnight and morning pattern or commonly persists during the part of the day you plan to visit.
This heatmap shows the average solar radiation reaching San Ramon by month and hour. Brighter cells indicate the strongest typical sun, while muted cells can reflect nighttime, shorter winter days, cloud cover, smoke, or terrain shading.
Each cell combines one month with one local hour. Hover over or focus on a cell for its value and sample coverage. The red marker shows the current month and hour.
How recent months compared at San Ramon
- October 2026 recap: October 2026 at San Ramon averaged a high of 78°F, 6°F warmer than October 2025 (72°F).
- Rain year: The 2025-26 rain year (Oct. 1 to Sep. 30) brought 23.2 in. of rain to San Ramon, 109% of the 21.3 in. normal.
Location Details
San Ramon weather questions
Everything you need to know about weather and visiting San Ramon
What is the weather like at San Ramon today?
It's 52°F at San Ramon right now, with a comfort score of 76 (great). Monday's forecast high at San Ramon is 56°F, 8°F below the mid November normal of 64°F. The best window today is 8 AM to 11 AM, at about 55°F with a 9 mph wind (comfort 57).
What is the best month to visit San Ramon?
By typical temperature, wind, cloud, humidity, and rain odds, the most comfortable months at San Ramon are September, June, and August. The best hours are usually 10 AM to 1 PM in September, 11 AM to 2 PM in June, and 10 AM to 1 PM in August. The warm season lasts about 3 months, from Jun 27 to Sep 26, when the average high is 82°F or warmer. Highs peak around Jul 8 at about 86°F.
What are the warmest and coldest months at San Ramon?
July is the warmest month at San Ramon, with an average high of 86°F. December is the coldest, with an average low of 40°F.
When does the fog burn off at San Ramon?
Fog or low cloud covers San Ramon in 35% of 8 AM hours in July, the foggiest month. It usually thins to a third of that by 10 AM. February mornings are the least foggy (10%).
When is it windiest at San Ramon?
From February through October, wind at San Ramon typically builds after 1 PM. In May it peaks around 5 PM, averaging 12 mph with 14% of those hours windy, while mornings average 7 mph.
How much rain does San Ramon get?
January is the wettest month (4.3 in.), out of about 21.3 in. a year. The rainy season runs from Nov 16 to Apr 2, when a day has at least a 20% chance of measurable rain. That stretch brings 80% of the year's rain. The 2025-26 rain year (Oct. 1 to Sep. 30) brought 23.2 in. of rain to San Ramon, 109% of the 21.3 in. normal.
How does San Ramon weather compare with Las Trampas Regional Wilderness?
Las Trampas Regional Wilderness sits 1,206 ft higher, 3.9 miles away. Its summer highs average 3°F cooler and its winter lows 1°F milder than San Ramon.
What kind of place is San Ramon?
San Ramon spreads across the southern San Ramon Valley and east into the newer Dougherty Valley. It reaches from the Las Trampas foothills on the west to grazed ridgelines on the east. Its office center at Bishop Ranch takes its name from a ranch begun in 1911 that was known as the largest single Bartlett pear orchard in the world. The Iron Horse Regional Trail runs north and south through the city, and Bollinger Canyon Road leads west into Las Trampas Regional Wilderness.
What is San Ramon weather like in November?
November at San Ramon averages a high of 64°F and a low of 44°F, with 2.1 in. of rain over about 6 rainy days. About 11% of morning hours are foggy. Afternoon wind averages 6 mph.
More about San Ramon weather
Guides that explain the weather here and nearby
Data sources and methods
- Monthly temperatures and precipitation: NOAA 1991-2020 normals.
- Fog, cloud, wind, sun, and comfort by hour and month: NOAA's HRRR hourly analysis from September 2014 to April 2026.
- Daily records and recent months: NOAA URMA and HRRR analyses, plus NOAA Stage IV precipitation.
- Nearby comparisons and regional rankings use the same hourly HRRR summaries for every destination in the region.
- Alerts: National Weather Service. Tides and ocean temperature: NOAA CO-OPS, where shown.
- All statements on this page are computed from these datasets, apart from the “What shapes the weather” guide, which cites its sources inline.
- City of San Ramon, Cooling centers (accessed 2026-10-27)
- City of San Ramon, Trails (accessed 2026-10-27)
- City of San Ramon, San Ramon facts (accessed 2026-10-27)
- East Bay Regional Park District, Las Trampas Regional Wilderness (accessed 2026-10-27)
- East Bay Regional Park District, Iron Horse Regional Trail (accessed 2026-10-27)
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