Black Diamond Mines Regional Preserve Weather
Park • San Francisco Bay Area
Black Diamond Mines Regional Preserve covers about 8,500 acres of grassy ridges and wooded canyons on Mount Diablo's northern foothills, just south of Pittsburg and Antioch. The East Bay Regional Park District runs it on the site of what was California's largest coal mining operation. Five towns, including Nortonville and Somersville, thrived here from the 1860s to about 1900, and sand for glassmaking was mined underground until 1949. Visitors can go underground on guided mine tours, and the hills hold the northernmost stands of Coulter pine.
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10-Day Forecast
Hour by hour
Hourly Forecast
Current Conditions
Comfort Breakdown
Black Diamond Mines Regional Preserve weather today and through the year
It's 53°F at Black Diamond Mines Regional Preserve right now (feels like 49°F), with 6 mph wind and a comfort score of 76. Monday's forecast high at Black Diamond Mines Regional Preserve is 53°F, 12°F below the mid November normal of 65°F. The best window today is 8 AM to 11 AM, at about 52°F with a 12 mph wind (comfort 56).
July is the warmest month at Black Diamond Mines Regional Preserve, with an average high of 89°F. December is the coldest, with an average low of 39°F. January is the wettest month (3.4 in.), out of about 15.8 in. a year. By typical temperature, wind, cloud, humidity, and rain odds, the most comfortable months at Black Diamond Mines Regional Preserve are September, October, and June. The best hours are usually 10 AM to 1 PM in September, noon to 3 PM in October, and 9 AM to noon in June.
Black Diamond sits between two climates. To the north, the land drops to Antioch, Pittsburg and the Delta, where the afternoon wind from the Carquinez Strait arrives. To the south rise the higher slopes of Mount Diablo. The preserve's ridges are high enough to catch that westerly breeze across their open grassland, so the crests are often windy while the sheltered canyon floors bake.
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 Black Diamond Mines Regional Preserve 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 52°F with a 12 mph wind (comfort 56).
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 Black Diamond Mines Regional Preserve, with a 59°F high and midday comfort near 77. Wednesday looks weakest (37).
Rain
Next good chance of rain: today (82%, about 0.12 in.).
Live weather map
Weather around Black Diamond Mines Regional Preserve right now
Overcast and 53° at Black Diamond Mines Regional Preserve right now.
About the live weather map for Black Diamond Mines Regional Preserve
The map centers on Black Diamond Mines Regional Preserve 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.
Black Diamond Mines Regional Preserve vs nearby places
Typical summer conditions compared with Black Diamond Mines Regional Preserve, 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 Black Diamond Mines Regional Preserve |
|---|---|---|---|---|---|
| Antioch | 4.5 mi | +5°F | 1% | 10 mph | about 5°F warmer on summer afternoons and calmer summer afternoons (10 vs 14 mph) |
| Pittsburg | 4.8 mi | +4°F | 2% | 10 mph | calmer summer afternoons (10 vs 14 mph) and about 4°F warmer on summer afternoons |
| Mount Diablo State Park | 6 mi | -8°F | 4% | 10 mph | 3,064 ft higher and about 8°F cooler on summer afternoons |
| Redwood Regional Park | 19.2 mi | -13°F | 53% | 10 mph | more summer morning fog (53% vs 2% of morning hours) and about 13°F cooler on summer afternoons |
| Montclair | 20.9 mi | -14°F | 53% | 8 mph | more summer morning fog (53% vs 2% of morning hours) and about 14°F cooler on summer afternoons |
| Claremont District | 21.7 mi | -14°F | 56% | 9 mph | more summer morning fog (56% vs 2% of morning hours) and about 14°F cooler on summer afternoons |
Places with a climate like Black Diamond Mines Regional Preserve's
- Wooden Valley (32 mi away): nearly the same temperatures every month
- Fairfield (22 mi away): nearly the same temperatures every month
- Suisun City (22 mi away): nearly the same temperatures every month
Climate Dashboard
Current conditions vs. NOAA normals and recent destination baseline
What the Black Diamond Mines Regional Preserve climate comparisons mean
These cards compare recent conditions at Black Diamond Mines Regional Preserve 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 Black Diamond Mines Regional Preserve 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.
Black Diamond Mines Regional Preserve weather by month
July is the warmest month at Black Diamond Mines Regional Preserve, with an average high of 89°F. December is the coldest, with an average low of 39°F. January is the wettest month (3.4 in.), out of about 15.8 in. a year. Morning fog peaks in December, when fog or low cloud covers 25% 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 Black Diamond Mines Regional Preserve are September, October, and June. The best hours are usually 10 AM to 1 PM in September, noon to 3 PM in October, and 9 AM to noon in June.
| Month | Avg high | Avg low | Rain | Rainy days | Morning fog | Midday cloud | Afternoon wind | Daylight | Comfort |
|---|---|---|---|---|---|---|---|---|---|
| Jan | 56°F | 40°F | 3.4 in | 8 | 22% | 34% | 8 mph | 9.8 h | 48 |
| Feb | 61°F | 42°F | 2.9 in | 7 | 9% | 23% | 10 mph | 10.7 h | 56 |
| Mar | 66°F | 45°F | 2.4 in | 7 | 5% | 27% | 10 mph | 11.9 h | 62 |
| Apr | 70°F | 47°F | 1.1 in | 5 | 4% | 19% | 11 mph | 13.2 h | 73 |
| May | 77°F | 51°F | 0.5 in | 3 | 4% | 13% | 13 mph | 14.2 h | 75 |
| Jun | 84°F | 56°F | 0.1 in | 2 | 2% | 4% | 14 mph | 14.8 h | 82 |
| Jul | 89°F | 59°F | 0.0 in | 0 | 3% | 3% | 14 mph | 14.5 h | 77 |
| Aug | 89°F | 58°F | 0.0 in | 1 | 3% | 4% | 13 mph | 13.6 h | 78 |
| Sep | 86°F | 57°F | 0.1 in | 1 | 2% | 7% | 11 mph | 12.3 h | 85 |
| Oct | 77°F | 52°F | 0.7 in | 4 | 4% | 11% | 9 mph | 11.1 h | 83 |
| Nov | 65°F | 45°F | 1.6 in | 5 | 11% | 22% | 7 mph | 10.0 h | 70 |
| Dec | 56°F | 39°F | 3.0 in | 7 | 25% | 37% | 8 mph | 9.5 h | 45 |
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 Black Diamond Mines Regional Preserve 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 Black Diamond Mines Regional Preserve has actually seen.
What makes Black Diamond Mines Regional Preserve's weather different
Among the 58 San Francisco Bay Area parks we track, Black Diamond Mines Regional Preserve has the least foggy summer mornings.
- #1of 58
least foggy summer morningsamong San Francisco Bay Area parks
When the fog burns off
27%of 9 AM hours foggy in December
Fog or low cloud covers Black Diamond Mines Regional Preserve in 27% of 9 AM hours in December, the foggiest month. It often lingers, and 15% of mid-afternoon hours are still foggy. June mornings are the least foggy (2%).
When the wind picks up
5 PMwhen afternoon wind builds, April–May
From April through May, wind at Black Diamond Mines Regional Preserve typically builds after 5 PM. In May it peaks around 11 PM, averaging 18 mph with 68% of those hours windy, while mornings average 13 mph. Overall, July is the windiest month, peaking near 21 mph around 2 AM.
Hot hours
2 habove 85°F on a typical July afternoon
In July, the average temperature stays at or above 85°F for 2 hours a day.
Microclimate
+5°FAntioch, 4.5 mi away, on summer afternoons
Antioch, 4.5 miles away, runs about 5°F warmer than Black Diamond Mines Regional Preserve on summer afternoons.
Elevation
−8°Fsummer afternoons at Mount Diablo State Park, 3,064 ft up
Mount Diablo State Park sits 3,064 ft higher, 6 miles away. Its summer highs average 8°F cooler and its winter lows 1°F milder than Black Diamond Mines Regional Preserve.
Daylight
9.5–14.8 hof daylight, Dec to Jun
Days at Black Diamond Mines Regional Preserve range from about 9.5 hours in December to 14.8 hours in June. In mid-June the sun sets around 8:31 PM, and in mid-December around 4:52 PM.
Seasons at Black Diamond Mines Regional Preserve
- Warm seasonJun 26 – Sep 24 · highs 85°F+
The warm season lasts about 3 months, from Jun 26 to Sep 24, when the average high is 85°F or warmer. Highs peak around Jul 8 at about 89°F.
- Cool seasonNov 26 – Feb 27 · highs 63°F or lower
The cool season runs from Nov 26 to Feb 27, when the average high is 63°F or lower. The coldest nights come around Dec 8, with an average low near 39°F.
- Rainy seasonNov 28 – Mar 21 · 69% of the year's rain
The rainy season runs from Nov 28 to Mar 21, when a day has at least a 20% chance of measurable rain. That stretch brings 69% 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 5 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, Black Diamond Mines Regional Preserve averaged 28 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 16 afternoons with wind of 20 mph or more at 2 PM. About 49 mornings a year had 3 or more hours of fog or low cloud.
In the same record, the hottest day was Jul 14, 2026 (97°F) and the coldest night was Feb 21, 2026 (34°F). The wettest day was Feb 18, 2026 (2.10 in.), and the strongest 2 PM gust was 46 mph on Feb 13, 2025.
- 28days at 90°F or hotter
- 0nights at or below freezing
- 10days with ½ in. of rain or more
- 16afternoons with 20+ mph wind
- 49mornings with 3+ hours of fog or low cloud
- Hottest day97°FJul 14, 2026
- Coldest night34°FFeb 21, 2026
- Wettest day2.10 inFeb 18, 2026
- Strongest 2 PM gust46 mphFeb 13, 2025
What shapes Black Diamond Mines Regional Preserve's weather
Black Diamond's summers bring the full heat of eastern Contra Costa County. The Air District says afternoons there frequently approach triple digits. The preserve's open grass slopes have little shade outside the oak and pine woodland in the canyons. The underground Greathouse Visitor Center, dug into the hill in the 1920s, is the one place out of the sun.
Winter rain turns the hills green and the trails muddy. On calm winter nights tule fog, a thick ground fog, can form over the Delta lowlands to the north, and in December it sometimes lingers into the afternoon. Spring brings what the park district calls some of the Bay Area's most remarkable wildflower displays. The weather stays mild until the hills dry out in early summer.
Tips for visiting Black Diamond Mines Regional Preserve
Reserve the Coal Mine Experience ahead
The underground tour runs Saturdays and Sundays year-round. Participants must be at least seven, groups are capped at 15, and advance reservations are highly recommended.
Time your visit to the gate hours
Gate hours change with the season, from 8 a.m. to 8 p.m. in spring and summer to 8 a.m. to 5 p.m. in late fall and winter.
Hike early in summer
Eastern Contra Costa afternoons frequently approach triple digits in summer, and most trails cross open grassland.
Leave pets out of the mine
Leashed dogs are allowed in the Greathouse Visitor Center but not on mine tours. Service animals are allowed on guided tours.
Black Diamond Mines Regional Preserve through the seasons
- Spring (March–May)
- Spring brings green hills, wildflowers and mild days that suit long hikes. The Stewartville backpack camp is open for spring, summer and fall stays.
- Summer (June–August)
- Summer is hot, dry and dusty on the trails. Plan hikes for the morning, or head underground for a mine tour.
- Fall (September–November)
- September is still warm, and October and November turn cooler and clearer. The grass stays dry and fire-prone until the first rains.
- Winter (December–February)
- Winter brings short gate hours, muddy trails after rain and cool days on the ridges, with fog on some mornings. Mine tours still run on weekends.
Activities and the weather that matters
- Underground mine tours: The tours work in any weather and are the best option on a hot summer weekend.
- Hiking the ridges and canyons: Hiking is best from late fall through spring. Summer afternoons are hot and exposed, and the ridges can be windy.
- Visiting Rose Hill Cemetery: Go in the morning or on a cool day, because summer afternoons on the grassy hillside are hot.
Official sources and current conditions
- East Bay Regional Park District: Black Diamond Mines Regional Preserve
- 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 | 58.9° / 46.4° | 6.5h | 3d | 1.72" | 19 |
| December 2024 | 67 | 55.2° / 45.6° | 4.5h | 11d | 3.78" | 9 |
| January 2025 | 81 | 55.6° / 42° | 7.1h | 2d | 0.09" | 21 |
| February 2025 | 77 | 57.4° / 44.6° | 7h | 2d | 4.74" | 15 |
| March 2025 | 84 | 58.9° / 45° | 9h | 1d | 1.41" | 22 |
| April 2025 | 91 | 67° / 50.1° | 10.1h | 1d | 0.4" | 27 |
| May 2025 | 94 | 76.1° / 56.1° | 12.5h | 0d | 0.17" | 31 |
| June 2025 | 93 | 81.3° / 60.1° | 12.9h | 0d | 0" | 30 |
| July 2025 | 92 | 81.9° / 59.7° | 12.6h | 1d | 0" | 31 |
| August 2025 | 92 | 87.2° / 65.6° | 11.5h | 0d | 0" | 31 |
| September 2025 | 91 | 81.4° / 64.1° | 10.1h | 0d | 0.13" | 27 |
| October 2025 | 89 | 69.6° / 55.1° | 7.8h | 0d | 1.64" | 26 |
| November 2025 | 73 | 59.8° / 49.5° | 5.7h | 12d | 2.76" | 15 |
| December 2025 | 58 | 51.3° / 43.2° | 4.5h | 19d | 2.87" | 2 |
| January 2026 | 70 | 55.5° / 43.8° | 6.3h | 15d | 3.18" | 11 |
| February 2026 | 75 | 59.5° / 46.2° | 6.6h | 7d | 4.9" | 15 |
| March 2026 | 95 | 73.3° / 56.7° | 9.8h | 0d | 0" | 30 |
| April 2026 | 86 | 65.8° / 50.4° | 9.1h | 0d | 3.04" | 21 |
| May 2026 | 92 | 73.4° / 55.4° | 12.1h | 1d | 0.39" | 30 |
| June 2026 | 93 | 80.5° / 60.6° | 12.8h | 0d | 0" | 30 |
| July 2026 | 91 | 85° / 64.6° | 12.2h | 0d | 0" | 31 |
| August 2026 | 92 | 86° / 64.5° | 11.3h | 0d | 0" | 31 |
| September 2026 | 95 | 79.1° / 59.9° | 10.4h | 0d | 0.02" | 30 |
| October 2026 | 89 | 75.3° / 58.4° | 8.3h | 2d | 0.39" | 29 |
Climate Trends
Average Temperature by Month
About the Black Diamond Mines Regional Preserve climate charts
The temperature chart compares average monthly highs and lows at Black Diamond Mines Regional Preserve, 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 Black Diamond Mines Regional Preserve. 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 Black Diamond Mines Regional Preserve, the warmest typical hour is 4 PM in July (86°F). The coldest is 7 AM in December (44°F).
- Fog: Fog or low cloud covers Black Diamond Mines Regional Preserve in 27% of 9 AM hours in December, the foggiest month. It often lingers, and 15% of mid-afternoon hours are still foggy. June mornings are the least foggy (2%).
- Wind: From April through May, wind at Black Diamond Mines Regional Preserve typically builds after 5 PM. In May it peaks around 11 PM, averaging 18 mph with 68% of those hours windy, while mornings average 13 mph. Overall, July is the windiest month, peaking near 21 mph around 2 AM.
- Cloud Cover: July middays are the clearest at Black Diamond Mines Regional Preserve (3% average cloud cover), and December middays are the cloudiest (37%).
- Solar Radiation: The strongest typical sun at Black Diamond Mines Regional Preserve comes at 1 PM in June, averaging 1010 W/m².
How to read the hourly heatmaps for Black Diamond Mines Regional Preserve
This heatmap shows how average temperature at Black Diamond Mines Regional Preserve 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 Black Diamond Mines Regional Preserve. 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 Black Diamond Mines Regional Preserve 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 Black Diamond Mines Regional Preserve 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 Black Diamond Mines Regional Preserve 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 Black Diamond Mines Regional Preserve
- October 2026 recap: October 2026 at Black Diamond Mines Regional Preserve averaged a high of 75°F, 6°F warmer than October 2025 (70°F).
- Rain year: The 2025-26 rain year (Oct. 1 to Sep. 30) brought 18.8 in. of rain to Black Diamond Mines Regional Preserve, 119% of the 15.8 in. normal.
Location Details
Black Diamond Mines Regional Preserve weather questions
Everything you need to know about weather and visiting Black Diamond Mines Regional Preserve
What is the weather like at Black Diamond Mines Regional Preserve today?
It's 53°F at Black Diamond Mines Regional Preserve right now, with a comfort score of 76 (great). Monday's forecast high at Black Diamond Mines Regional Preserve is 53°F, 12°F below the mid November normal of 65°F. The best window today is 8 AM to 11 AM, at about 52°F with a 12 mph wind (comfort 56).
What is the best month to visit Black Diamond Mines Regional Preserve?
By typical temperature, wind, cloud, humidity, and rain odds, the most comfortable months at Black Diamond Mines Regional Preserve are September, October, and June. The best hours are usually 10 AM to 1 PM in September, noon to 3 PM in October, and 9 AM to noon in June. The warm season lasts about 3 months, from Jun 26 to Sep 24, when the average high is 85°F or warmer. Highs peak around Jul 8 at about 89°F.
What are the warmest and coldest months at Black Diamond Mines Regional Preserve?
July is the warmest month at Black Diamond Mines Regional Preserve, with an average high of 89°F. December is the coldest, with an average low of 39°F.
When does the fog burn off at Black Diamond Mines Regional Preserve?
Fog or low cloud covers Black Diamond Mines Regional Preserve in 27% of 9 AM hours in December, the foggiest month. It often lingers, and 15% of mid-afternoon hours are still foggy. June mornings are the least foggy (2%).
When is it windiest at Black Diamond Mines Regional Preserve?
From April through May, wind at Black Diamond Mines Regional Preserve typically builds after 5 PM. In May it peaks around 11 PM, averaging 18 mph with 68% of those hours windy, while mornings average 13 mph. Overall, July is the windiest month, peaking near 21 mph around 2 AM.
How much rain does Black Diamond Mines Regional Preserve get?
January is the wettest month (3.4 in.), out of about 15.8 in. a year. The rainy season runs from Nov 28 to Mar 21, when a day has at least a 20% chance of measurable rain. That stretch brings 69% of the year's rain. The 2025-26 rain year (Oct. 1 to Sep. 30) brought 18.8 in. of rain to Black Diamond Mines Regional Preserve, 119% of the 15.8 in. normal.
How does Black Diamond Mines Regional Preserve weather compare with Antioch?
Antioch, 4.5 miles away, runs about 5°F warmer than Black Diamond Mines Regional Preserve on summer afternoons.
What kind of place is Black Diamond Mines Regional Preserve?
Black Diamond Mines Regional Preserve covers about 8,500 acres of grassy ridges and wooded canyons on Mount Diablo's northern foothills, just south of Pittsburg and Antioch. The East Bay Regional Park District runs it on the site of what was California's largest coal mining operation. Five towns, including Nortonville and Somersville, thrived here from the 1860s to about 1900, and sand for glassmaking was mined underground until 1949. Visitors can go underground on guided mine tours, and the hills hold the northernmost stands of Coulter pine.
What is Black Diamond Mines Regional Preserve weather like in November?
November at Black Diamond Mines Regional Preserve averages a high of 65°F and a low of 45°F, with 1.6 in. of rain over about 5 rainy days. About 11% of morning hours are foggy. Afternoon wind averages 7 mph.
More about Black Diamond Mines Regional Preserve 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, Black Diamond Mines Regional Preserve (accessed 2026-10-27)
- Bay Area Air Quality Management District, Contra Costa County community page (updated Apr 21, 2017) (accessed 2026-10-27)
Rendered 2026-11-15T12:16:28.990Z.