Alhambra Valley Weather
Town • San Francisco Bay Area
Alhambra Valley is a small rural community in the Briones Hills just south and west of downtown Martinez. It follows Alhambra Creek upstream from the John Muir National Historic Site toward Briones Regional Park. Small ranches and large rural lots line its narrow, winding roads. The park district's Alhambra Creek Valley staging area off Reliez Valley Road is the northern gateway into Briones. Unlike Martinez on the strait, the valley sits behind a ring of grassy hills, out of the direct path of the afternoon wind.
Plan your week
10-Day Forecast
Hour by hour
Hourly Forecast
Current Conditions
Comfort Breakdown
Alhambra Valley weather today and through the year
It's 54°F at Alhambra Valley right now (feels like 49°F), with 9 mph wind and a comfort score of 76. Monday's forecast high at Alhambra Valley is 55°F, 9°F below the mid November normal of 64°F. The best window today is 11 AM to 2 PM, at about 51°F with a 7 mph wind (comfort 57).
August is the warmest month at Alhambra Valley, with an average high of 84°F. January is the coldest, with an average low of 40°F. December is the wettest month (5.0 in.), out of about 24.5 in. a year. By typical temperature, wind, cloud, humidity, and rain odds, the most comfortable months at Alhambra Valley are September, June, and July. The best hours are usually 9 AM to noon in September, 10 AM to 1 PM in June, and 9 AM to noon in July.
Mount Wanda and the other ridges around Alhambra Valley partly screen it from the wind that blows through the Carquinez Strait a couple of miles north. The Martinez waterfront takes that cool marine air head-on, while the valley gets a softened, later version of it. Summer afternoons here feel much like downtown Martinez, and usually not as hot as the open floor of the Diablo Valley around Concord.
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 Alhambra Valley in the next few days
No active National Weather Service alerts for this location.
Best time to go
The best window today is 11 AM to 2 PM, at about 51°F with a 7 mph wind (comfort 57).
Best day this week
Of the next 7 days, Friday looks best for Alhambra Valley, with a 60°F high and midday comfort near 79. Wednesday looks weakest (53).
Rain
Next good chance of rain: today (74%, about 0.16 in.).
Live weather map
Weather around Alhambra Valley right now
Overcast and 54° at Alhambra Valley right now.
About the live weather map for Alhambra Valley
The map centers on Alhambra Valley 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.
Alhambra Valley vs nearby places
Typical summer conditions compared with Alhambra Valley, 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 Alhambra Valley |
|---|---|---|---|---|---|
| Briones Regional Park | 2.6 mi | -4°F | 23% | 11 mph | about 4°F cooler on summer afternoons |
| Martinez | 3.5 mi | +1°F | 10% | 12 mph | a very similar climate |
| Pleasant Hill | 4.4 mi | +4°F | 10% | 7 mph | calmer summer afternoons (7 vs 11 mph) and about 4°F warmer on summer afternoons |
| Baker Beach | 22.5 mi | -24°F | 45% | 16 mph | about 24°F cooler on summer afternoons and more summer morning fog (45% vs 14% of morning hours) |
| Rodeo Beach | 23.8 mi | -24°F | 48% | 13 mph | about 24°F cooler on summer afternoons and more summer morning fog (48% vs 14% of morning hours) |
| Ocean Beach | 25 mi | -24°F | 49% | 11 mph | about 24°F cooler on summer afternoons and more summer morning fog (49% vs 14% of morning hours) |
Places with a climate like Alhambra Valley's
- Mission Peak Regional Preserve (34 mi away): similar temperatures through the year
- Fremont (30 mi away): similar temperatures through the year
- Union City (26 mi away): similar temperatures through the year
Climate Dashboard
Current conditions vs. NOAA normals and recent destination baseline
What the Alhambra Valley climate comparisons mean
These cards compare recent conditions at Alhambra Valley 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 Alhambra Valley 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.
Alhambra Valley weather by month
August is the warmest month at Alhambra Valley, with an average high of 84°F. January is the coldest, with an average low of 40°F. December is the wettest month (5.0 in.), out of about 24.5 in. a year. Morning fog peaks in December, when fog or low cloud covers 28% 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 Alhambra Valley are September, June, and July. The best hours are usually 9 AM to noon in September, 10 AM to 1 PM in June, and 9 AM to noon in July.
| Month | Avg high | Avg low | Rain | Rainy days | Morning fog | Midday cloud | Afternoon wind | Daylight | Comfort |
|---|---|---|---|---|---|---|---|---|---|
| Jan | 56°F | 40°F | 4.9 in | 9 | 24% | 36% | 7 mph | 9.8 h | 35 |
| Feb | 60°F | 42°F | 4.7 in | 9 | 11% | 25% | 8 mph | 10.7 h | 60 |
| Mar | 64°F | 44°F | 3.7 in | 8 | 6% | 27% | 9 mph | 11.9 h | 65 |
| Apr | 68°F | 46°F | 1.7 in | 5 | 5% | 21% | 10 mph | 13.2 h | 75 |
| May | 73°F | 50°F | 0.8 in | 4 | 10% | 16% | 12 mph | 14.2 h | 78 |
| Jun | 80°F | 54°F | 0.1 in | 2 | 13% | 6% | 12 mph | 14.8 h | 86 |
| Jul | 83°F | 56°F | 0.0 in | 0 | 16% | 6% | 11 mph | 14.5 h | 84 |
| Aug | 84°F | 57°F | 0.0 in | 1 | 13% | 7% | 11 mph | 13.6 h | 84 |
| Sep | 82°F | 55°F | 0.1 in | 1 | 8% | 10% | 9 mph | 12.3 h | 87 |
| Oct | 75°F | 51°F | 1.1 in | 4 | 6% | 14% | 8 mph | 11.1 h | 84 |
| Nov | 64°F | 45°F | 2.5 in | 7 | 12% | 24% | 7 mph | 10.0 h | 68 |
| Dec | 56°F | 40°F | 5.0 in | 9 | 28% | 40% | 7 mph | 9.5 h | 32 |
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.
What makes Alhambra Valley's weather different
When the fog burns off
30%of 8 AM hours foggy in December
Fog or low cloud covers Alhambra Valley in 30% of 8 AM hours in December, the foggiest month. It often lingers, and 15% of mid-afternoon hours are still foggy. April mornings are the least foggy (5%).
When the wind picks up
4 PMwhen afternoon wind builds, March–September
From March through September, wind at Alhambra Valley typically builds after 4 PM. In June it peaks around 6 PM, averaging 14 mph with 41% of those hours windy, while mornings average 10 mph.
Daylight
9.5–14.8 hof daylight, Dec to Jun
Days at Alhambra Valley range from about 9.5 hours in December to 14.8 hours in June. In mid-June the sun sets around 8:33 PM, and in mid-December around 4:54 PM.
Seasons at Alhambra Valley
- Warm seasonJun 29 – Sep 25 · highs 81°F+
The warm season lasts about 2.9 months, from Jun 29 to Sep 25, when the average high is 81°F or warmer. Highs peak around Aug 8 at about 84°F.
- Cool seasonNov 29 – Feb 25 · highs 61°F or lower
The cool season runs from Nov 29 to Feb 25, when the average high is 61°F or lower. The coldest nights come around Jan 8, with an average low near 40°F.
- Rainy seasonNov 9 – Apr 8 · 84% of the year's rain
The rainy season runs from Nov 9 to Apr 8, when a day has at least a 20% chance of measurable rain. That stretch brings 84% 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 Oct 28 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, Alhambra Valley averaged 23 days a year at 90°F or hotter and no freezing nights. It averaged 18 days a year with at least half an inch of rain and 4 afternoons with wind of 20 mph or more at 2 PM. About 70 mornings a year had 3 or more hours of fog or low cloud.
In the same record, the hottest day was Sep 9, 2026 (99°F) and the coldest night was Feb 20, 2026 (35°F). The wettest day was Nov 23, 2024 (2.88 in.), and the strongest 2 PM gust was 42 mph on Feb 4, 2025.
- 23days at 90°F or hotter
- 0nights at or below freezing
- 18days with ½ in. of rain or more
- 4afternoons with 20+ mph wind
- 70mornings with 3+ hours of fog or low cloud
- Hottest day99°FSep 9, 2026
- Coldest night35°FFeb 20, 2026
- Wettest day2.88 inNov 23, 2024
- Strongest 2 PM gust42 mphFeb 4, 2025
What shapes Alhambra Valley's weather
The ring of hills around Alhambra Valley also traps cold air at night. On clear winter nights, air chilled on the hillsides drains down into the creek bottom and pools there. The valley floor can be noticeably colder at dawn than Martinez or Pleasant Hill. Morning fog can sit in the low spots after the hills are in sun.
The grass on the surrounding hills cures to gold by early summer. Dry, hot afternoons and the occasional fall offshore wind, a dry wind blowing from inland toward the coast, make fire the main seasonal hazard in the valley.
Tips for visiting Alhambra Valley
Hike Mount Wanda with sun protection
The National Park Service says Mount Wanda's trails can be challenging and the sun intense. Bring your own water. The trailhead lot is next to Franklin Canyon Road.
Enter Briones from the Alhambra Creek side
The Alhambra Creek Valley staging area is off Reliez Valley Road near Martinez. Bring cash, because Briones takes only cash for parking when the kiosk is staffed.
Share the trail with cattle
Cattle graze in several parts of Briones. The park asks visitors to call if they have concerns about grazing animals on the trail.
Visit the Muir home Tuesday to Saturday
The John Muir National Historic Site at the valley's mouth is open Tuesday through Saturday, 10 a.m. to 5 p.m., and closed Sunday and Monday.
Alhambra Valley through the seasons
- Spring (March–May)
- Spring brings green hills, a flowing creek and comfortable hiking weather, and it is the valley at its best.
- Summer (June–August)
- Summer afternoons are warm, with dry, golden hillsides and a breeze that builds toward evening. Hike Mount Wanda and Briones early in the day.
- Fall (September–October)
- Fall days stay warm, and fire risk is highest of the year until the first rains turn the hills green again.
- Winter (November–February)
- Winter is the rainy season. Cold air pools on the valley floor on clear nights, bringing chilly dawns and patchy morning fog.
Activities and the weather that matters
- Hiking Mount Wanda: Mount Wanda is open daily from sunrise to sunset and is best in the cool season. Summer sun on the open slopes is intense.
- Hiking and riding in Briones: Briones trails are green and muddy in winter, ideal in spring, and hot and dusty on summer afternoons.
- Cycling the valley roads: Calm mornings are best. On winter mornings, watch for fog and slick pavement in shaded hollows.
Official sources and current conditions
- NPS: Mount Wanda
- NPS: John Muir National Historic Site
- East Bay Regional Park District: Briones Regional Park
- East Bay Regional Park District: Alerts and closures
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 | 80 | 61.3° / 46.5° | 6.5h | 2d | 4.69" | 18 |
| December 2024 | 66 | 56.1° / 45.6° | 4.2h | 11d | 6.75" | 9 |
| January 2025 | 81 | 57.6° / 42.1° | 6.9h | 3d | 0.21" | 19 |
| February 2025 | 77 | 59.4° / 44.4° | 6.9h | 3d | 8.71" | 16 |
| March 2025 | 83 | 60.6° / 45.5° | 9h | 0d | 2.65" | 20 |
| April 2025 | 91 | 66.8° / 47.9° | 9.8h | 0d | 0.31" | 26 |
| May 2025 | 95 | 74.4° / 51.9° | 12.5h | 1d | 0.22" | 31 |
| June 2025 | 95 | 76.5° / 52.9° | 12.8h | 2d | 0" | 30 |
| July 2025 | 92 | 76.2° / 54.8° | 12.4h | 6d | 0" | 31 |
| August 2025 | 93 | 84.4° / 58° | 11.5h | 1d | 0" | 31 |
| September 2025 | 92 | 80.1° / 59.9° | 10h | 0d | 0.16" | 29 |
| October 2025 | 89 | 71.7° / 53.7° | 7.9h | 0d | 1.77" | 26 |
| November 2025 | 75 | 62° / 49.8° | 5.3h | 10d | 2.98" | 16 |
| December 2025 | 55 | 52.6° / 44.3° | 2.7h | 20d | 5.5" | 3 |
| January 2026 | 69 | 57.4° / 44.5° | 5.9h | 15d | 4.46" | 9 |
| February 2026 | 77 | 62.1° / 46.3° | 6.9h | 6d | 5.23" | 15 |
| March 2026 | 95 | 75.3° / 53.3° | 9.8h | 1d | 0.03" | 30 |
| April 2026 | 87 | 66.3° / 49.1° | 9.3h | 2d | 4.73" | 22 |
| May 2026 | 92 | 72° / 52.4° | 11.8h | 2d | 0.69" | 30 |
| June 2026 | 93 | 76.7° / 55.1° | 12.6h | 3d | 0" | 29 |
| July 2026 | 93 | 81.3° / 57.3° | 11.8h | 2d | 0" | 30 |
| August 2026 | 93 | 82.2° / 57.5° | 11.3h | 1d | 0" | 31 |
| September 2026 | 94 | 79° / 56.9° | 10.5h | 0d | 0.51" | 28 |
| October 2026 | 90 | 77.2° / 55.4° | 8.2h | 1d | 0.56" | 28 |
Climate Trends
Average Temperature by Month
About the Alhambra Valley climate charts
The temperature chart compares average monthly highs and lows at Alhambra Valley, 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 Alhambra Valley. 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 Alhambra Valley, the warmest typical hour is 3 PM in August (83°F). The coldest is 7 AM in December (44°F).
- Fog: Fog or low cloud covers Alhambra Valley in 30% of 8 AM hours in December, the foggiest month. It often lingers, and 15% of mid-afternoon hours are still foggy. April mornings are the least foggy (5%).
- Wind: From March through September, wind at Alhambra Valley typically builds after 4 PM. In June it peaks around 6 PM, averaging 14 mph with 41% of those hours windy, while mornings average 10 mph.
- Cloud Cover: July middays are the clearest at Alhambra Valley (6% average cloud cover), and December middays are the cloudiest (40%).
- Solar Radiation: The strongest typical sun at Alhambra Valley comes at 1 PM in July, averaging 995 W/m².
How to read the hourly heatmaps for Alhambra Valley
This heatmap shows how average temperature at Alhambra Valley 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 Alhambra Valley. 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 Alhambra Valley 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 Alhambra Valley 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 Alhambra Valley 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 Alhambra Valley
- October 2026 recap: October 2026 at Alhambra Valley averaged a high of 77°F, 5°F warmer than October 2025 (72°F).
- Rain year: The 2025-26 rain year (Oct. 1 to Sep. 30) brought 25.9 in. of rain to Alhambra Valley, 106% of the 24.5 in. normal.
Location Details
Alhambra Valley weather questions
Everything you need to know about weather and visiting Alhambra Valley
What is the weather like at Alhambra Valley today?
It's 54°F at Alhambra Valley right now, with a comfort score of 76 (great). Monday's forecast high at Alhambra Valley is 55°F, 9°F below the mid November normal of 64°F. The best window today is 11 AM to 2 PM, at about 51°F with a 7 mph wind (comfort 57).
What is the best month to visit Alhambra Valley?
By typical temperature, wind, cloud, humidity, and rain odds, the most comfortable months at Alhambra Valley are September, June, and July. The best hours are usually 9 AM to noon in September, 10 AM to 1 PM in June, and 9 AM to noon in July. The warm season lasts about 2.9 months, from Jun 29 to Sep 25, when the average high is 81°F or warmer. Highs peak around Aug 8 at about 84°F.
What are the warmest and coldest months at Alhambra Valley?
August is the warmest month at Alhambra Valley, with an average high of 84°F. January is the coldest, with an average low of 40°F.
When does the fog burn off at Alhambra Valley?
Fog or low cloud covers Alhambra Valley in 30% of 8 AM hours in December, the foggiest month. It often lingers, and 15% of mid-afternoon hours are still foggy. April mornings are the least foggy (5%).
When is it windiest at Alhambra Valley?
From March through September, wind at Alhambra Valley typically builds after 4 PM. In June it peaks around 6 PM, averaging 14 mph with 41% of those hours windy, while mornings average 10 mph.
How much rain does Alhambra Valley get?
December is the wettest month (5.0 in.), out of about 24.5 in. a year. The rainy season runs from Nov 9 to Apr 8, when a day has at least a 20% chance of measurable rain. That stretch brings 84% of the year's rain. The 2025-26 rain year (Oct. 1 to Sep. 30) brought 25.9 in. of rain to Alhambra Valley, 106% of the 24.5 in. normal.
What kind of place is Alhambra Valley?
Alhambra Valley is a small rural community in the Briones Hills just south and west of downtown Martinez. It follows Alhambra Creek upstream from the John Muir National Historic Site toward Briones Regional Park. Small ranches and large rural lots line its narrow, winding roads. The park district's Alhambra Creek Valley staging area off Reliez Valley Road is the northern gateway into Briones. Unlike Martinez on the strait, the valley sits behind a ring of grassy hills, out of the direct path of the afternoon wind.
What is Alhambra Valley weather like in November?
November at Alhambra Valley averages a high of 64°F and a low of 45°F, with 2.5 in. of rain over about 7 rainy days. About 12% of morning hours are foggy. Afternoon wind averages 7 mph.
More about Alhambra Valley 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.
- National Park Service, Mount Wanda (John Muir National Historic Site) (accessed 2026-10-27)
- National Park Service, John Muir National Historic Site basic information (accessed 2026-10-27)
- East Bay Regional Park District, Briones Regional Park (accessed 2026-10-27)
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