Sunol Regional Wilderness Weather
Park • San Francisco Bay Area
Sunol Regional Wilderness covers the canyon of Alameda Creek on the inland side of the Mission Peak ridge, about four miles off I-680 by Calaveras Road. The East Bay Regional Park District runs its 6,859 acres of oak woodland, grassland, and creekside alder, willow, and sycamore, where cattle still graze. Alameda County's largest stream runs through it, and the gorge long called Little Yosemite, now the Alameda Creek Overlook, lies about two miles upstream from the visitor center.
Plan your week
10-Day Forecast
Hour by hour
Hourly Forecast
Current Conditions
Comfort Breakdown
Sunol Regional Wilderness weather today and through the year
It's 52°F at Sunol Regional Wilderness right now (feels like 48°F), with 6 mph wind and a comfort score of 76. Monday's forecast high at Sunol Regional Wilderness is 54°F, 9°F below the mid November normal of 63°F. The best window today is 10 AM to 1 PM, at about 53°F with a 5 mph wind (comfort 63).
July is the warmest month at Sunol Regional Wilderness, with an average high of 85°F. January is the coldest, with an average low of 40°F. December is the wettest month (4.5 in.), out of about 22.8 in. a year. By typical temperature, wind, cloud, humidity, and rain odds, the most comfortable months at Sunol Regional Wilderness are September, June, and August. The best hours are usually 9 AM to noon in September, 9 AM to noon in June, and 8 AM to 11 AM in August.
The Mission Peak ridge stands between Sunol and the bay. The afternoon sea breeze that cools Fremont has to squeeze through Niles Canyon or spill over the crest to get here. As a result, the canyon floor runs a few degrees hotter on summer afternoons than the Fremont flats only a few miles west.
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 Sunol Regional Wilderness in the next few days
No active National Weather Service alerts for this location.
Best time to go
The best window today is 10 AM to 1 PM, at about 53°F with a 5 mph wind (comfort 63).
Hiking conditions
Best hiking day this week: Monday, with 9 daylight hours that are dry, 45 to 80°F, and under 18 mph wind. 4 of the next 7 days have at least 4 such hours.
Best day this week
Of the next 7 days, Friday looks best for Sunol Regional Wilderness, with a 60°F high and midday comfort near 75. Wednesday looks weakest (50).
Rain
Next good chance of rain: today (81%, about 0.19 in.).
Live weather map
Weather around Sunol Regional Wilderness right now
Overcast and 52° at Sunol Regional Wilderness right now.
About the live weather map for Sunol Regional Wilderness
The map centers on Sunol Regional Wilderness 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.
Sunol Regional Wilderness vs nearby places
Typical summer conditions compared with Sunol Regional Wilderness, 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 Sunol Regional Wilderness |
|---|---|---|---|---|---|
| Mission Peak Regional Preserve | 2.8 mi | -5°F | 21% | 10 mph | 1,944 ft higher and about 5°F cooler on summer afternoons |
| Milpitas | 7.1 mi | -1°F | 16% | 10 mph | about 37% less rain a year |
| Fremont | 8.9 mi | -3°F | 17% | 9 mph | a very similar climate |
| Don Edwards Wildlife Refuge | 13 mi | -18°F | 18% | 16 mph | about 18°F cooler on summer afternoons and windier summer afternoons (16 vs 10 mph) |
| Coyote Hills Regional Park | 14.5 mi | -19°F | 21% | 14 mph | about 19°F cooler on summer afternoons and windier summer afternoons (14 vs 10 mph) |
| Foster City | 24.3 mi | -18°F | 14% | 12 mph | about 18°F cooler on summer afternoons |
Places with a climate like Sunol Regional Wilderness's
- Morgan Territory Regional Preserve (21 mi away): similar temperatures through the year
- Las Trampas Regional Wilderness (24 mi away): similar temperatures through the year
- Alhambra Valley (35 mi away): similar temperatures through the year
Climate Dashboard
Current conditions vs. NOAA normals and recent destination baseline
What the Sunol Regional Wilderness climate comparisons mean
These cards compare recent conditions at Sunol Regional Wilderness 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 Sunol Regional Wilderness 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.
Sunol Regional Wilderness weather by month
July is the warmest month at Sunol Regional Wilderness, with an average high of 85°F. January is the coldest, with an average low of 40°F. December is the wettest month (4.5 in.), out of about 22.8 in. a year. Morning fog peaks in December, when fog or low cloud covers 18% of the hours from 6 to 10 AM. July has the clearest middays, with clouds covering about 3% of the sky from 11 AM to 3 PM.
By typical temperature, wind, cloud, humidity, and rain odds, the most comfortable months at Sunol Regional Wilderness are September, June, and August. The best hours are usually 9 AM to noon in September, 9 AM to noon in June, and 8 AM to 11 AM in August.
| Month | Avg high | Avg low | Rain | Rainy days | Morning fog | Midday cloud | Afternoon wind | Daylight | Comfort |
|---|---|---|---|---|---|---|---|---|---|
| Jan | 56°F | 40°F | 4.1 in | 8 | 13% | 29% | 8 mph | 9.9 h | 58 |
| Feb | 58°F | 42°F | 3.9 in | 8 | 9% | 23% | 10 mph | 10.8 h | 60 |
| Mar | 62°F | 43°F | 3.8 in | 8 | 7% | 28% | 9 mph | 11.9 h | 64 |
| Apr | 66°F | 45°F | 1.9 in | 6 | 7% | 21% | 10 mph | 13.2 h | 73 |
| May | 72°F | 50°F | 0.7 in | 4 | 9% | 15% | 11 mph | 14.2 h | 79 |
| Jun | 80°F | 54°F | 0.2 in | 2 | 8% | 5% | 11 mph | 14.7 h | 87 |
| Jul | 85°F | 59°F | 0.0 in | 0 | 9% | 3% | 10 mph | 14.5 h | 86 |
| Aug | 85°F | 59°F | 0.0 in | 1 | 13% | 4% | 10 mph | 13.6 h | 87 |
| Sep | 82°F | 58°F | 0.1 in | 2 | 10% | 8% | 9 mph | 12.3 h | 90 |
| Oct | 74°F | 52°F | 1.1 in | 4 | 9% | 11% | 9 mph | 11.1 h | 84 |
| Nov | 63°F | 45°F | 2.4 in | 7 | 8% | 19% | 8 mph | 10.1 h | 69 |
| Dec | 56°F | 40°F | 4.5 in | 9 | 18% | 29% | 8 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.
What makes Sunol Regional Wilderness's weather different
When the fog burns off
noonwhen December fog usually thins (21% foggy at 9 AM)
Fog or low cloud covers Sunol Regional Wilderness in 21% of 9 AM hours in December, the foggiest month. It usually thins to a third of that by noon. April mornings are the least foggy (7%).
When the wind picks up
1 PMwhen afternoon wind builds, February–October
From February through October, wind at Sunol Regional Wilderness typically builds after 1 PM. In May it peaks around 5 PM, averaging 12 mph with 9% of those hours windy, while mornings average 6 mph.
Elevation
−5°Fsummer afternoons at Mission Peak Regional Preserve, 1,944 ft up
Mission Peak Regional Preserve sits 1,944 ft higher, 2.8 miles away. Its summer highs average 5°F cooler than Sunol Regional Wilderness.
Daylight
9.6–14.7 hof daylight, Dec to Jun
Days at Sunol Regional Wilderness range from about 9.6 hours in December to 14.7 hours in June. In mid-June the sun sets around 8:28 PM, and in mid-December around 4:55 PM.
Seasons at Sunol Regional Wilderness
- Warm seasonJun 28 – Sep 25 · highs 81°F+
The warm season lasts about 3 months, from Jun 28 to Sep 25, when the average high is 81°F or warmer. Highs peak around Jul 8 at about 85°F.
- Cool seasonNov 29 – Mar 1 · highs 60°F or lower
The cool season runs from Nov 29 to Mar 1, when the average high is 60°F or lower. The coldest nights come around Jan 8, with an average low near 40°F.
- Rainy seasonNov 9 – Apr 11 · 82% of the year's rain
The rainy season runs from Nov 9 to Apr 11, when a day has at least a 20% chance of measurable rain. That stretch brings 82% 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 26.
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, Sunol Regional Wilderness averaged 23 days a year at 90°F or hotter and no freezing nights. It averaged 10 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 30 mornings a year had 3 or more hours of fog or low cloud.
In the same record, the hottest day was Sep 9, 2026 (97°F) and the coldest night was Feb 18, 2026 (36°F). The wettest day was Oct 14, 2025 (1.90 in.), and the strongest 2 PM gust was 47 mph on Mar 12, 2025.
- 23days at 90°F or hotter
- 0nights at or below freezing
- 10days with ½ in. of rain or more
- 4afternoons with 20+ mph wind
- 30mornings with 3+ hours of fog or low cloud
- Hottest day97°FSep 9, 2026
- Coldest night36°FFeb 18, 2026
- Wettest day1.90 inOct 14, 2025
- Strongest 2 PM gust47 mphMar 12, 2025
What shapes Sunol Regional Wilderness's weather
On clear nights at Sunol Regional Wilderness, cool air slides off the surrounding hills after sunset. It collects along Alameda Creek and the Sunol Valley floor, so mornings at the visitor center can be colder than in Fremont.
Winter storms swell Alameda Creek with runoff from a large share of the Diablo Range, and the creek runs hardest through the rocky gorge after heavy rain. That moisture sets up the spring wildflower bloom, but by early summer the grass has dried brown. The dry hills face real fire risk when fall offshore winds, which blow from the interior toward the coast, arrive.
Tips for visiting Sunol Regional Wilderness
Bring all the water you need
The park has no drinking water, which matters on hot summer afternoons in the canyon.
Stay out of Alameda Creek
Swimming and wading are not allowed, to protect endangered species.
Respect the water department boundary
Land around the Alameda Creek Overlook is leased from the San Francisco Water Department, so stay within the signed boundaries.
Watch the seasonal closing time
The park opens at 8 a.m. Closing runs from 5 p.m. in winter to 9 p.m. from mid-May to early September.
Leave the barbecue at home
The park district bans open fires and barbecues of any type at Sunol. Gas-fueled stoves are allowed only at Alameda Grove and School Camp.
Sunol Regional Wilderness through the seasons
- Spring (March–May)
- Spring is the wildflower season. Poppies, goldfields, and lupines bloom from late March to early May, and the creek is still running strong.
- Summer (June–August)
- Afternoons get hot on the canyon floor, which sits behind the ridge from the bay. Hike early and carry water, since the park has none.
- Fall (September–October)
- Fall stays warm and dry into October, with the driest grass of the year. The gate closes at 7 p.m. in October and 5 p.m. from November 1.
- Winter (November–February)
- Winter mornings are cold along the creek, and the hills turn green after the first good rains. Storms can send Alameda Creek roaring through the gorge.
Activities and the weather that matters
- Hiking to the Alameda Creek Overlook: The overlook is about two miles upstream from the visitor center. The walk is pleasant on spring and fall mornings and punishing on summer afternoons.
- Wildflower walks: The bloom runs from late March to early May, and a mild day after rain is ideal. The visitor center lends a wildflower identification kit.
- Backpacking: Spring and fall nights are the comfortable choice. Camping is by reservation, made two or more business days ahead.
Official sources and current conditions
- East Bay Regional Park District: Sunol Wilderness
- East Bay Regional Park District: alerts and closures
- National Weather Service, San Francisco Bay Area forecast office
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 | 59.7° / 47.4° | 6.9h | 0d | 1.65" | 20 |
| December 2024 | 75 | 58.9° / 48.4° | 5.3h | 5d | 3" | 12 |
| January 2025 | 83 | 57.2° / 44.5° | 7.3h | 1d | 0.14" | 22 |
| February 2025 | 79 | 58° / 46° | 7h | 2d | 3.87" | 16 |
| March 2025 | 82 | 58.1° / 45.4° | 8.5h | 0d | 2.25" | 19 |
| April 2025 | 92 | 64.2° / 48.5° | 9.8h | 0d | 0.57" | 25 |
| May 2025 | 95 | 72.1° / 52.2° | 12.2h | 0d | 0.16" | 30 |
| June 2025 | 97 | 77.8° / 55.8° | 12.7h | 0d | 0" | 30 |
| July 2025 | 95 | 79.9° / 57.6° | 12.3h | 0d | 0" | 31 |
| August 2025 | 94 | 84° / 61° | 11.3h | 1d | 0" | 31 |
| September 2025 | 94 | 79.2° / 62.1° | 10.1h | 0d | 0.11" | 30 |
| October 2025 | 90 | 69.5° / 54.7° | 8.1h | 2d | 2.48" | 26 |
| November 2025 | 80 | 62.2° / 51.1° | 6.9h | 7d | 2.94" | 15 |
| December 2025 | 75 | 56.8° / 47.2° | 5.7h | 12d | 1.41" | 8 |
| January 2026 | 81 | 58.5° / 49.2° | 6.9h | 2d | 2.43" | 21 |
| February 2026 | 79 | 60.6° / 49.6° | 7h | 6d | 3.63" | 18 |
| March 2026 | 96 | 72.8° / 57.8° | 9.9h | 0d | 0" | 30 |
| April 2026 | 88 | 64.8° / 49.6° | 9.5h | 0d | 2.8" | 25 |
| May 2026 | 93 | 71.4° / 52.9° | 11.6h | 1d | 0.71" | 29 |
| June 2026 | 96 | 78.8° / 56.5° | 12.4h | 0d | 0" | 30 |
| July 2026 | 94 | 81.9° / 60.1° | 12.1h | 0d | 0" | 31 |
| August 2026 | 93 | 84.2° / 61.9° | 11.2h | 1d | 0" | 31 |
| September 2026 | 96 | 77.6° / 58.4° | 10.4h | 0d | 0.04" | 30 |
| October 2026 | 90 | 75.6° / 60° | 8.4h | 0d | 0.16" | 28 |
Climate Trends
Average Temperature by Month
About the Sunol Regional Wilderness climate charts
The temperature chart compares average monthly highs and lows at Sunol Regional Wilderness, 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 Sunol Regional Wilderness. 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 Sunol Regional Wilderness, the warmest typical hour is 3 PM in July (83°F). The coldest is 7 AM in December (46°F).
- Fog: Fog or low cloud covers Sunol Regional Wilderness in 21% of 9 AM hours in December, the foggiest month. It usually thins to a third of that by noon. April mornings are the least foggy (7%).
- Wind: From February through October, wind at Sunol Regional Wilderness typically builds after 1 PM. In May it peaks around 5 PM, averaging 12 mph with 9% of those hours windy, while mornings average 6 mph.
- Cloud Cover: July middays are the clearest at Sunol Regional Wilderness (3% average cloud cover), and December middays are the cloudiest (29%).
- Solar Radiation: The strongest typical sun at Sunol Regional Wilderness comes at 1 PM in July, averaging 1006 W/m².
How to read the hourly heatmaps for Sunol Regional Wilderness
This heatmap shows how average temperature at Sunol Regional Wilderness 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 Sunol Regional Wilderness. 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 Sunol Regional Wilderness 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 Sunol Regional Wilderness 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 Sunol Regional Wilderness 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 Sunol Regional Wilderness
- October 2026 recap: October 2026 at Sunol Regional Wilderness averaged a high of 76°F, 6°F warmer than October 2025 (69°F).
- Rain year: The 2025-26 rain year (Oct. 1 to Sep. 30) brought 16.4 in. of rain to Sunol Regional Wilderness, 72% of the 22.8 in. normal.
Location Details
Sunol Regional Wilderness weather questions
Everything you need to know about weather and visiting Sunol Regional Wilderness
What is the weather like at Sunol Regional Wilderness today?
It's 52°F at Sunol Regional Wilderness right now, with a comfort score of 76 (great). Monday's forecast high at Sunol Regional Wilderness is 54°F, 9°F below the mid November normal of 63°F. The best window today is 10 AM to 1 PM, at about 53°F with a 5 mph wind (comfort 63).
What is the best month to visit Sunol Regional Wilderness?
By typical temperature, wind, cloud, humidity, and rain odds, the most comfortable months at Sunol Regional Wilderness are September, June, and August. The best hours are usually 9 AM to noon in September, 9 AM to noon in June, and 8 AM to 11 AM in August. The warm season lasts about 3 months, from Jun 28 to Sep 25, when the average high is 81°F or warmer. Highs peak around Jul 8 at about 85°F.
What are the warmest and coldest months at Sunol Regional Wilderness?
July is the warmest month at Sunol Regional Wilderness, with an average high of 85°F. January is the coldest, with an average low of 40°F.
When does the fog burn off at Sunol Regional Wilderness?
Fog or low cloud covers Sunol Regional Wilderness in 21% of 9 AM hours in December, the foggiest month. It usually thins to a third of that by noon. April mornings are the least foggy (7%).
When is it windiest at Sunol Regional Wilderness?
From February through October, wind at Sunol Regional Wilderness typically builds after 1 PM. In May it peaks around 5 PM, averaging 12 mph with 9% of those hours windy, while mornings average 6 mph.
How much rain does Sunol Regional Wilderness get?
December is the wettest month (4.5 in.), out of about 22.8 in. a year. The rainy season runs from Nov 9 to Apr 11, when a day has at least a 20% chance of measurable rain. That stretch brings 82% of the year's rain. The 2025-26 rain year (Oct. 1 to Sep. 30) brought 16.4 in. of rain to Sunol Regional Wilderness, 72% of the 22.8 in. normal.
How does Sunol Regional Wilderness weather compare with Mission Peak Regional Preserve?
Mission Peak Regional Preserve sits 1,944 ft higher, 2.8 miles away. Its summer highs average 5°F cooler than Sunol Regional Wilderness.
Can you swim at Little Yosemite?
No. The park district does not allow swimming or wading in Alameda Creek, to protect endangered species. The gorge, now called the Alameda Creek Overlook, is for viewing from the trail.
What kind of place is Sunol Regional Wilderness?
Sunol Regional Wilderness covers the canyon of Alameda Creek on the inland side of the Mission Peak ridge, about four miles off I-680 by Calaveras Road. The East Bay Regional Park District runs its 6,859 acres of oak woodland, grassland, and creekside alder, willow, and sycamore, where cattle still graze. Alameda County's largest stream runs through it, and the gorge long called Little Yosemite, now the Alameda Creek Overlook, lies about two miles upstream from the visitor center.
What is Sunol Regional Wilderness weather like in November?
November at Sunol Regional Wilderness averages a high of 63°F and a low of 45°F, with 2.4 in. of rain over about 7 rainy days. Afternoon wind averages 8 mph.
More about Sunol Regional Wilderness 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.
- East Bay Regional Park District, Sunol Wilderness Regional Preserve (accessed 2026-10-27)
- East Bay Regional Park District, Alerts & Closures (accessed 2026-10-27)
Rendered 2026-11-15T12:16:29.421Z.