Mt. Diablo Summit Weather

Park • San Francisco Bay Area

Highest peak in the Bay Area, usually sunny

68°
😊
Comfort Score
93(A-)
Excellent
Weather updated September 30, 2026 at 10:01 PM PDT

Mt. Diablo Summit weather at a glance

Mt. Diablo Summit is a park at 3,849 feet in San Francisco Bay Area. Highest peak in the Bay Area, usually sunny. Notable features include hiking, views, above-fog, and sunny.

Current conditions are 68°F, feeling like 62°F, with 23% humidity, winds near 3 mph, 0% cloud cover, and a 0% chance of precipitation. Mild with clear skies.

The location-specific climate baseline shows an average daily high of 69°F and an average low of 50°F, with about 10.5 hours of sunshine per day and 1.8 hours of morning fog per day. Expected annual precipitation is approximately 18.1 inches.

Plan your week

10-Day Forecast

Drag or swipe to browse
  1. Best day
    Today
    Sep 30
    79°59°
    Comfort
    95
    0%
    Precip 0 in
  2. Thu
    Oct 1
    80°66°
    Comfort
    95
    0%
    Precip 0 in
  3. Fri
    Oct 2
    81°58°
    Comfort
    83
    0%
    Precip 0 in
  4. Sat
    Oct 3
    87°54°
    Comfort
    79
    0%
    Precip 0 in
  5. Sun
    Oct 4
    85°58°
    Comfort
    84
    2%
    Precip 0 in
  6. Mon
    Oct 5
    87°57°
    Comfort
    80
    0%
    Precip 0 in
  7. Tue
    Oct 6
    87°59°
    Comfort
    81
    0%
    Precip 0 in
  8. Wed
    Oct 7
    88°59°
    Comfort
    76
    1%
    Precip 0 in
  9. Thu
    Oct 8
    90°60°
    Comfort
    68
    0%
    Precip 0 in
  10. Fri
    Oct 9
    82°46°
    Comfort
    86
    0%
    Precip 0 in

Hour by hour

Hourly Forecast

Drag or swipe to browse
  1. Today
    Now
    68°
    Comfort
    93
    0%
    0 in
  2. Today
    11 PM
    68°
    Comfort
    93
    0%
    0 in
  3. Thu
    12 AM
    67°
    Comfort
    92
    0%
    0 in
  4. Thu
    1 AM
    67°
    Comfort
    91
    0%
    0 in
  5. Thu
    2 AM
    68°
    Comfort
    92
    0%
    0 in
  6. Thu
    3 AM
    69°
    Comfort
    93
    0%
    0 in
  7. Thu
    4 AM
    69°
    Comfort
    91
    0%
    0 in
  8. Thu
    5 AM
    68°
    Comfort
    90
    0%
    0 in
  9. Thu
    6 AM
    67°
    Comfort
    89
    0%
    0 in
  10. Thu
    7 AM
    66°
    Comfort
    90
    0%
    0 in
  11. Sunrise7:03 AM
  12. Thu
    8 AM
    68°
    Comfort
    92
    0%
    0 in
  13. Thu
    9 AM
    72°
    Comfort
    96
    0%
    0 in
  14. Thu
    10 AM
    76°
    Comfort
    99
    0%
    0 in
  15. Thu
    11 AM
    77°
    Comfort
    99
    0%
    0 in
  16. Thu
    12 PM
    78°
    Comfort
    99
    0%
    0 in
  17. Thu
    1 PM
    79°
    Comfort
    98
    0%
    0 in
  18. Thu
    2 PM
    80°
    Comfort
    97
    0%
    0 in
  19. Thu
    3 PM
    79°
    Comfort
    99
    0%
    0 in
  20. Thu
    4 PM
    78°
    Comfort
    98
    0%
    0 in
  21. Thu
    5 PM
    77°
    Comfort
    99
    0%
    0 in
  22. Thu
    6 PM
    74°
    Comfort
    98
    0%
    0 in
  23. Sunset6:50 PM
  24. Thu
    7 PM
    69°
    Comfort
    93
    0%
    0 in
  25. Thu
    8 PM
    69°
    Comfort
    92
    0%
    0 in
  26. Thu
    9 PM
    67°
    Comfort
    90
    0%
    0 in
  27. Thu
    10 PM
    67°
    Comfort
    91
    0%
    0 in
  28. Thu
    11 PM
    66°
    Comfort
    90
    0%
    0 in
  29. Fri
    12 AM
    68°
    Comfort
    92
    0%
    0 in
  30. Fri
    1 AM
    68°
    Comfort
    92
    0%
    0 in
  31. Fri
    2 AM
    66°
    Comfort
    89
    0%
    0 in
  32. Fri
    3 AM
    66°
    Comfort
    89
    0%
    0 in
  33. Fri
    4 AM
    66°
    Comfort
    88
    0%
    0 in
  34. Fri
    5 AM
    65°
    Comfort
    87
    0%
    0 in
  35. Fri
    6 AM
    65°
    Comfort
    82
    0%
    0 in
  36. Fri
    7 AM
    68°
    Comfort
    85
    0%
    0 in
  37. Sunrise7:04 AM
  38. Fri
    8 AM
    67°
    Comfort
    86
    0%
    0 in
  39. Fri
    9 AM
    73°
    Comfort
    97
    0%
    0 in
  40. Fri
    10 AM
    77°
    Comfort
    98
    0%
    0 in
  41. Fri
    11 AM
    79°
    Comfort
    98
    0%
    0 in
  42. Fri
    12 PM
    80°
    Comfort
    98
    0%
    0 in
  43. Fri
    1 PM
    81°
    Comfort
    97
    0%
    0 in
  44. Fri
    2 PM
    80°
    Comfort
    96
    0%
    0 in
  45. Fri
    3 PM
    79°
    Comfort
    95
    0%
    0 in
  46. Fri
    4 PM
    80°
    Comfort
    96
    0%
    0 in
  47. Fri
    5 PM
    79°
    Comfort
    95
    0%
    0 in
  48. Fri
    6 PM
    75°
    Comfort
    95
    0%
    0 in
  49. Sunset6:48 PM
  50. Fri
    7 PM
    66°
    Comfort
    87
    0%
    0 in
  51. Fri
    8 PM
    63°
    Comfort
    87
    0%
    0 in
  52. Fri
    9 PM
    61°
    Comfort
    82
    0%
    0 in

Current Conditions

Temperature
68°F
Feels like 62°F
Humidity
23%
Dew point 29°F
Wind
3 mph
NW • Gusts 3 mph
Cloud Cover
0%
Precip Chance
0%

Comfort Breakdown

Less comfortableMore comfortable
Thermal88
Wind100
Stars Visible100
Moisture87
Precipitation100

Weather Maps

About the weather maps for Mt. Diablo Summit

Each preview is centered on Mt. Diablo Summit, with the red pin marking its approximate location. Satellite imagery provides cloud context, radar shows nearby precipitation, and the fog view shows the marine-layer or low-cloud field when that regional layer is available.

These images cover a wider area than the point forecast, so a nearby cloud or rain band may not be directly over Mt. Diablo Summit. Open a preview for the interactive map and its latest timestamp before making a weather-sensitive decision.

Nearby Temperature Comparison

Conditions at nearby San Francisco Bay Area destinations

Tip: Bay Area temps can vary 20-30°F within a short distance due to microclimates.

Climate Dashboard

Current conditions vs. NOAA normals and recent destination baseline

Today's High vs Normal
79°Fforecast
6° above normal
Normal: 73°F
Rainfall Year-to-Date
15.7"
16% above average
30-yr avg: 13.5"
Sunny Days
27last 28 days
Right on track
Typical: 27
Foggy Days
0last 28 days
vs 4 typical
Clearer than usual
Avg Wind Speed
8.3 mphlast 28 days
1.6 mph windier than baseline
Typical: 6.7 mph
Comfort Score
9628-day avg
On par with typical
Recent baseline: 96
What the Mt. Diablo Summit climate comparisons mean

These cards compare recent conditions at Mt. Diablo Summit 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 Mt. Diablo Summit 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.

Historical Climate Data

Long-term weather patterns and climate data

Data sources: NOAA URMA for recent temperature history, NOAA Stage IV for recent precipitation, NOAA HRRR for fog, cloud, wind, humidity, and sunshine signals, and NOAA 1991-2020 climate normals for long-term baselines.

Climate Overview

Based on NOAA 30-year temperature/rain normals (1991-2020) with recent fog/sun baseline

80
Avg Comfort
68.9°
Avg High
50.1°
Avg Low
66%
Perfect Days
☀️ Avg Sunshine10.5h/day
🌫️ Avg Fog1.8h/day
💧 Avg Annual Rain18.1"
🌧️ Rainy Days/yr68 (19%)
🌫️ Foggy Days/yr90
✨ Perfect Days (80+)443

🌟 Best Months to Visit

1. June91
79.1° / 55.6° · ☀️ 13.5h
3 foggy days · 1 rainy days
2. July84
84.8° / 60.5° · ☀️ 13.6h
4 foggy days · 0 rainy days
3. May81
71.4° / 50° · ☀️ 12.8h
4 foggy days · 4 rainy days

⚠️ Challenging Months

1. December28
53.7° / 41° · ☀️ 6.8h
💧 3.1" · 11 rainy days · 13 foggy days
2. January28
53.9° / 41.9° · ☀️ 7h
💧 3.1" · 11 rainy days · 14 foggy days
3. February35
56.4° / 42.3° · ☀️ 8.3h
💧 2.8" · 10 rainy days · 11 foggy days

Monthly Breakdown

MonthComfortHigh/Low☀️ Sun🌫️ Fog💧 RainPerfect
October 20247647.5° / 39°8h0d0.09"1
November 20246347.4° / 39.3°6.4h6d2.76"8
December 20246151.9° / 43.9°4.8h12d5.97"11
January 20257148.7° / 40.3°7.1h4d0.17"10
February 20256147.7° / 38.7°6.1h8d7.51"7
March 20256146.8° / 37°7.6h11d2.49"9
April 20258054.6° / 44.4°9.7h7d0.43"20
May 20259063.2° / 51.2°12.5h3d0.25"28
June 20259871.8° / 60.6°13h0d0"30
July 20259673.4° / 64.1°12.7h2d0"30
August 20259678° / 68.2°11.6h0d0"31
September 20259169.7° / 59.9°9.8h6d0.32"24
October 20258158.3° / 49°8h7d2.18"20
November 20257255.9° / 47.9°6.4h8d3.71"15
December 20256755.5° / 47.3°5.1h12d4.1"13
January 20267054.3° / 46.6°6.5h12d4.24"17
February 20266851° / 42.5°6.8h6d6.19"13
March 20269263.6° / 53.6°9.7h1d0.02"27
April 20267353.1° / 42.2°8.9h8d4.47"17
May 20268661.7° / 49.9°11.9h6d0.76"22
June 20269570.6° / 58.4°12.7h2d0"28
July 20269676.4° / 65.6°12.3h0d0.03"31
August 20269578.5° / 67.7°11.3h0d0"31
Last updated: 9/2/2026

Climate Trends

Average Temperature by Month

83°F70°F58°F45°F33°FOct '24Nov '24Dec '24Jan '25Feb '25Mar '25Apr '25May '25Jun '25Jul '25Aug '25Sep '25Oct '25Nov '25Dec '25Jan '26Feb '26Mar '26Apr '26May '26Jun '26Jul '26Aug '26
Average High
Average Low
About the Mt. Diablo Summit climate charts

The temperature chart compares average monthly highs and lows at Mt. Diablo Summit, 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 Mt. Diablo Summit. 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

How to read the temperature heatmap for Mt. Diablo Summit

This heatmap shows how average temperature at Mt. Diablo Summit changes by hour and month. Read left to right for the seasons and top to bottom for the time of day; warmer colors identify the usual afternoon peaks and cooler colors show overnight and winter lows.

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 to read the fog heatmap for Mt. Diablo Summit

This heatmap shows when fog or low cloud is most likely at Mt. Diablo Summit. Darker cells mark month-and-hour combinations with a stronger historical fog signal, which helps separate overnight or morning fog from cloud that tends to linger into the afternoon.

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 to read the wind heatmap for Mt. Diablo Summit

This heatmap shows the typical hourly wind pattern at Mt. Diablo Summit through the year. It makes recurring afternoon wind, calmer overnight periods, and seasonal changes easier to compare than a single daily wind value.

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 to read the cloud cover heatmap for Mt. Diablo Summit

This heatmap shows average cloud cover at Mt. Diablo Summit 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.

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 to read the solar radiation heatmap for Mt. Diablo Summit

This heatmap shows the average solar radiation reaching Mt. Diablo Summit 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.

Loading interactive climate heatmaps…

Location Details

📍
Coordinates
37.8816, -121.9142
⛰️
Elevation
3849 ft
🏷️
Type
Park
✨
Amenities
🅿️ parking🚻 restrooms
🏷️
Tags
#hiking#views#above-fog#sunny
Map
Loading map...
Get Directions →

Frequently Asked Questions

Everything you need to know about weather and visiting Mt. Diablo Summit

What is the weather at Mt. Diablo Summit right now?

Current conditions at Mt. Diablo Summit are 68°F, feeling like 62°F, with 23% humidity, winds near 3 mph, 0% cloud cover, and a 0% chance of precipitation. Mild with clear skies

What temperatures are typical at Mt. Diablo Summit?

The location-specific record for 1991-01-01 through 2020-12-31 shows an average daily high of 69°F and an average low of 50°F at Mt. Diablo Summit. These are averages across the year; the monthly climate table on this page shows the warmer and cooler seasons separately.

How much rain does Mt. Diablo Summit get?

The location-specific climate baseline estimates about 18.1 inches of precipitation and 68 days with measurable rain in a typical year at Mt. Diablo Summit. The monthly breakdown shows when that rain is most likely.

How often is Mt. Diablo Summit foggy?

Mt. Diablo Summit averages about 1.8 hours of morning fog per day across the location-specific climate baseline, with approximately 90 foggy days in a typical year. Fog varies considerably by season, so check the monthly breakdown and current forecast for visit planning.

What are the best months to visit Mt. Diablo Summit for comfortable weather?

Based on the destination's recorded comfort, temperature, sunshine, rain, and fog data, the strongest months are June 2025 (72°F/61°F average high/low and a 98 comfort score), July 2025 (73°F/64°F average high/low and a 96 comfort score), and August 2025 (78°F/68°F average high/low and a 96 comfort score). “Best” depends on the activity, so use the monthly table for the exact tradeoffs.

What kind of destination is Mt. Diablo Summit?

Mt. Diablo Summit is a park at 3,849 feet. Highest peak in the Bay Area, usually sunny. Notable features include hiking, views, above-fog, and sunny.

💡 Local Tip: San Francisco Bay Area weather can change dramatically within short distances and throughout the day. Always check current conditions before visiting Mt. Diablo Summit.