California mountains

Junipero Serra Peak mountain forecast

5,856 ft (1,785 m) · prominence 4,446 ft (1,355 m) · California

At the summit’s height the GFS model has 59°F and wind from the SSW at 12 mph, Sat, Sep 26, 11:00 AM PDT. The freezing level is at 14,606 ft, above the summit. The National Weather Service forecast for today: mostly sunny, high 67°F at its grid elevation of 5,325 ft.

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The summit on the map

Junipero Serra Peak and the summits and ski areas around it. Each has its own page.

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Now

Summit
5,856 ft (1,785 m)
Forecast grid ground
5,325 ft (1,623 m)
Summit temperature
59°F
Summit wind
SSW 12 mph
Freezing level
14,606 ft
High at the summit, by lapse rate
65°F

The last tile carries the Weather Service’s high from its grid’s 5,325 ft up 531 ft to the summit at the standard atmosphere’s 6.5 °C per kilometer (about 3.6 °F per 1,000 ft). Real lapse rates vary: an inversion can make the summit warmer than the valley.

At the summit’s height

Temperature, wind and wind chill up there, and the freezing level, every six hours for three days.

TimeTempWindWind chillFreezing level
Sat, Sep 26, 11:00 AM PDT59°FSSW 12 mph14,606 ft8,750 ft above the summit
Sat, Sep 26, 5:00 PM PDT60°FSSW 12 mph14,446 ft8,589 ft above the summit
Sat, Sep 26, 11:00 PM PDT59°FSSW 13 mph14,088 ft8,232 ft above the summit
Sun, Sep 27, 5:00 AM PDT57°FSSW 12 mph13,488 ft7,631 ft above the summit
Sun, Sep 27, 11:00 AM PDT55°FSW 8 mph12,769 ft6,913 ft above the summit
Sun, Sep 27, 5:00 PM PDT54°FWNW 9 mph11,834 ft5,978 ft above the summit
Sun, Sep 27, 11:00 PM PDT52°FWNW 12 mph11,115 ft5,259 ft above the summit
Mon, Sep 28, 5:00 AM PDT50°FNW 15 mph44°F10,735 ft4,879 ft above the summit
Mon, Sep 28, 11:00 AM PDT50°FN 10 mph10,705 ft4,849 ft above the summit
Mon, Sep 28, 5:00 PM PDT54°FN 16 mph13,914 ft8,058 ft above the summit
Mon, Sep 28, 11:00 PM PDT58°FN 16 mph15,151 ft9,295 ft above the summit
Tue, Sep 29, 5:00 AM PDT61°FN 17 mph15,627 ft9,770 ft above the summit

NOAA’s GFS model, run Sat, Sep 26, 5:00 AM PDT, interpolated to 5,856 ft between its pressure levels: the free air over the summit, which on a ridge is close to what a climber feels and in a sheltered spot is more than it. Wind chill is the National Weather Service’s formula, given where the temperature is 50°F or less and the wind above 3 mph.

The National Weather Service forecast at the summit

PeriodTempWindForecast
TodayHigh 67°FS 5 mphMostly sunny. High near 67, with temperatures falling to around 65 in the afternoon. South wind around 5 mph.
TonightLow 53°FSSW 5 mphPartly cloudy, with a low around 53. South southwest wind around 5 mph.
SundayHigh 60°FWNW 6 mphSunny. High near 60, with temperatures falling to around 58 in the afternoon. West northwest wind around 6 mph.
Sunday NightLow 49°FNW 7 mphClear, with a low around 49. Northwest wind around 7 mph.
MondayHigh 63°FNNW 5-8 mphSunny, with a high near 63. North northwest wind 5 to 8 mph.
Monday NightLow 58°FNNW 8 mphClear, with a low around 58.
TuesdayHigh 72°FNNW 2-7 mphSunny, with a high near 72.
Tuesday NightLow 63°FN 2-7 mphClear, with a low around 63.
WednesdayHigh 75°FNE 2 mphSunny, with a high near 75.
Wednesday NightLow 63°FNW 2 mphMostly clear, with a low around 63.

The Weather Service’s forecast asked at the summit’s coordinates (36.1456, -121.4190), by its office in San Francisco Bay Area, CA. Its grid cell is 2.5 km across and sits at 5,325 ft (1,623 m), 531 ft below the summit, so its temperatures and winds are for that height.

Cloud base and the summit

TimeSkyTemp and dew pointCloud base
Sat, Sep 26, 11:00 AM PDTMostly Sunny64°F / 30°F13,081 ftBase above the summit
Sat, Sep 26, 5:00 PM PDTMostly Sunny65°F / 34°F12,374 ftBase above the summit
Sat, Sep 26, 11:00 PM PDTPartly Cloudy58°F / 31°F11,458 ftBase above the summit
Sun, Sep 27, 5:00 AM PDTPartly Cloudy54°F / 23°F12,379 ftBase above the summit
Sun, Sep 27, 11:00 AM PDTMostly Sunny57°F / 26°F12,392 ftBase above the summit
Sun, Sep 27, 5:00 PM PDTSunny58°F / 33°F11,003 ftBase above the summit
Sun, Sep 27, 11:00 PM PDTClear53°F / 33°F9,895 ftBase above the summit
Mon, Sep 28, 5:00 AM PDTClear50°F / 28°F10,337 ftBase above the summit
Mon, Sep 28, 11:00 AM PDTSunny56°F / 28°F11,691 ftBase above the summit
Mon, Sep 28, 5:00 PM PDTSunny62°F / 32°F12,174 ftBase above the summit
Mon, Sep 28, 11:00 PM PDTClear59°F / 31°F11,704 ftBase above the summit
Tue, Sep 29, 5:00 AM PDTClear59°F / 23°F13,527 ftBase above the summit

An estimate: the height a rising parcel of the grid’s air would reach saturation, about 125 m for every degree Celsius between temperature and dew point (Espy’s rule), added to the grid’s ground. It fits cumulus and fog made on the spot, not a deck of stratus carried in from elsewhere.

Snow

No snow in the National Weather Service’s forecast for the summit’s grid cell over the next several days.

Sunrise and sunset

DayFirst lightSunriseSunsetLast lightDaylight
September 266:31 AM6:57 AM6:56 PM7:22 PM11h 59m
September 276:32 AM6:58 AM6:55 PM7:20 PM11h 57m
September 286:33 AM6:59 AM6:53 PM7:19 PM11h 54m
September 296:34 AM6:59 AM6:52 PM7:17 PM11h 53m
September 306:35 AM7:00 AM6:50 PM7:16 PM11h 50m
October 16:35 AM7:01 AM6:49 PM7:15 PM11h 48m
October 26:36 AM7:02 AM6:48 PM7:13 PM11h 46m

For a sea-level horizon at the summit’s position, local time. From a summit the horizon sits lower, so the sun is seen a few minutes before sunrise and after sunset; a ridge to the east or west does the opposite.

Elevation
5,856 ft (1,785 m)
Prominence
4,446 ft (1,355 m)
Coordinates
36.1456, -121.4190
Nearest town
Greenfield

What this means

Why a summit forecast differs
The air cools with height, by about 3.6°F per 1,000 feet on average, and the wind above a ridge blows at the speed of the free atmosphere rather than slowed by the valley floor. A town’s forecast says little about the top of the mountain above it.
Freezing level
The height where the air is at 32°F (0°C). Above it precipitation falls as snow and wet rock freezes; the snow line usually sits a few hundred to a thousand feet below it.
Wind chill
How cold the air feels on exposed skin, from the temperature and the wind, by the National Weather Service’s 2001 formula.
Cloud base
Where cloud begins. When it is below the summit, the top is in cloud: no view, and in cold air, rime ice and poor visibility.
Prominence
How far a summit rises above the lowest contour line that encircles it and no higher summit: the measure of a mountain’s own height, not its neighbors’.

Nearby

Summits

Forecasts from the National Weather Service. Summit-height temperature, wind and freezing level from NOAA’s Global Forecast System on NOAA Open Data. Summits from Wikidata (CC0): prominence >= 600 m, or elevation >= 4267 m, or >= 12 Wikipedia editions; English Wikipedia article required; read 2026-09-25. Mountain weather changes fast; check the forecast again before you go.