Rancho San Antonio Weather
Park • San Francisco Bay Area
Rancho San Antonio joins a 2,180-acre open space preserve to a 293-acre Santa Clara County park at the end of Cristo Rey Drive in Cupertino. It sits right where the foothills rise off the valley floor. The Midpeninsula Regional Open Space District manages both, with more than 25 miles of trail. Most visitors stay low, around Deer Hollow Farm and the fern-lined Wildcat Canyon loop. The Black Mountain Trail climbs about four miles through chaparral and oak to a 2,800-foot summit above Stevens Creek Canyon.
Plan your week
10-Day Forecast
Hour by hour
Hourly Forecast
Current Conditions
Comfort Breakdown
Rancho San Antonio weather today and through the year
It's 53°F at Rancho San Antonio right now (feels like 49°F), with 7 mph wind and a comfort score of 76. Monday's forecast high at Rancho San Antonio is 56°F, 10°F below the mid November normal of 66°F. The best window today is 8 AM to 11 AM, at about 56°F with a 7 mph wind (comfort 60).
August is the warmest month at Rancho San Antonio, with an average high of 83°F. December is the coldest, with an average low of 39°F. February is the wettest month (4.8 in.), out of about 23.8 in. a year. By typical temperature, wind, cloud, humidity, and rain odds, the most comfortable months at Rancho San Antonio are September, July, and June. The best hours are usually 10 AM to 1 PM in September, 9 AM to noon in July, and 10 AM to 1 PM in June.
The trailheads sit at the western edge of the Santa Clara Valley, so the lower park keeps the valley's summer routine. The air is nearly calm from evening until around midday, then a northwest sea breeze blows in off San Francisco Bay through the afternoon. The marine layer is the cool, moist ocean air that carries fog. When it is deep, low clouds that formed overnight can hang over the parking lots into late morning before burning off.
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 Rancho San Antonio 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 56°F with a 7 mph wind (comfort 60).
Hiking conditions
Best hiking day this week: Friday, 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 Rancho San Antonio, with a 59°F high and midday comfort near 73. Today looks weakest (53).
Rain
Next good chance of rain: today (88%, about 0.38 in.).
Live weather map
Weather around Rancho San Antonio right now
Overcast and 53° at Rancho San Antonio right now.
About the live weather map for Rancho San Antonio
The map centers on Rancho San Antonio 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.
Rancho San Antonio vs nearby places
Typical summer conditions compared with Rancho San Antonio, 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 Rancho San Antonio |
|---|---|---|---|---|---|
| Cupertino | 2.7 mi | +2°F | 12% | 9 mph | a very similar climate |
| Sunnyvale | 3.6 mi | -2°F | 16% | 10 mph | a very similar climate |
| Mountain View | 3.8 mi | -3°F | 17% | 10 mph | about 25% less rain a year |
| Año Nuevo State Park | 20.3 mi | -23°F | 42% | 14 mph | about 23°F cooler on summer afternoons and more summer morning fog (42% vs 16% of morning hours) |
| Año Nuevo Point | 20.9 mi | -23°F | 42% | 14 mph | about 23°F cooler on summer afternoons and more summer morning fog (42% vs 16% of morning hours) |
| Half Moon Bay State Beach | 22.5 mi | -20°F | 54% | 9 mph | about 20°F cooler on summer afternoons and more summer morning fog (54% vs 16% of morning hours) |
Places with a climate like Rancho San Antonio's
- Gilroy (36 mi away): nearly the same temperatures every month
- American Canyon (59 mi away): similar temperatures through the year
- Milpitas (12 mi away): similar temperatures through the year
Climate Dashboard
Current conditions vs. NOAA normals and recent destination baseline
What the Rancho San Antonio climate comparisons mean
These cards compare recent conditions at Rancho San Antonio 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 Rancho San Antonio 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.
Rancho San Antonio weather by month
August is the warmest month at Rancho San Antonio, with an average high of 83°F. December is the coldest, with an average low of 39°F. February is the wettest month (4.8 in.), out of about 23.8 in. a year. Morning fog peaks in August, when fog or low cloud covers 19% of the hours from 6 to 10 AM. July has the clearest middays, with clouds covering about 10% of the sky from 11 AM to 3 PM.
By typical temperature, wind, cloud, humidity, and rain odds, the most comfortable months at Rancho San Antonio are September, July, and June. The best hours are usually 10 AM to 1 PM in September, 9 AM to noon in July, and 10 AM to 1 PM in June.
| Month | Avg high | Avg low | Rain | Rainy days | Morning fog | Midday cloud | Afternoon wind | Daylight | Comfort |
|---|---|---|---|---|---|---|---|---|---|
| Jan | 60°F | 39°F | 4.8 in | 9 | 10% | 30% | 6 mph | 9.9 h | 61 |
| Feb | 62°F | 41°F | 4.8 in | 9 | 9% | 26% | 8 mph | 10.8 h | 63 |
| Mar | 66°F | 43°F | 3.7 in | 8 | 6% | 29% | 8 mph | 11.9 h | 66 |
| Apr | 69°F | 44°F | 1.6 in | 5 | 6% | 24% | 8 mph | 13.2 h | 77 |
| May | 74°F | 48°F | 0.7 in | 3 | 7% | 21% | 9 mph | 14.2 h | 81 |
| Jun | 80°F | 51°F | 0.2 in | 2 | 11% | 11% | 9 mph | 14.7 h | 85 |
| Jul | 83°F | 54°F | 0.0 in | 0 | 18% | 10% | 9 mph | 14.5 h | 86 |
| Aug | 83°F | 54°F | 0.0 in | 1 | 19% | 11% | 9 mph | 13.5 h | 85 |
| Sep | 82°F | 53°F | 0.1 in | 1 | 12% | 14% | 8 mph | 12.3 h | 88 |
| Oct | 77°F | 48°F | 1.0 in | 4 | 10% | 15% | 7 mph | 11.1 h | 85 |
| Nov | 66°F | 42°F | 2.3 in | 6 | 9% | 20% | 6 mph | 10.1 h | 72 |
| Dec | 59°F | 39°F | 4.7 in | 9 | 14% | 31% | 6 mph | 9.6 h | 59 |
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 Rancho San Antonio's weather different
When the fog burns off
10 AMwhen August fog usually thins (29% foggy at 8 AM)
Fog or low cloud covers Rancho San Antonio in 29% of 8 AM hours in August, the foggiest month. It usually thins to a third of that by 10 AM. April mornings are the least foggy (6%).
When the wind picks up
noonwhen afternoon wind builds, February–October
From February through October, wind at Rancho San Antonio typically builds after noon. In June it peaks around 3 PM, averaging 10 mph, while mornings average 4 mph.
Daylight
9.6–14.7 hof daylight, Dec to Jun
Days at Rancho San Antonio range from about 9.6 hours in December to 14.7 hours in June. In mid-June the sun sets around 8:29 PM, and in mid-December around 4:56 PM.
Seasons at Rancho San Antonio
- Warm seasonJun 28 – Sep 26 · highs 81°F+
The warm season lasts about 3 months, from Jun 28 to Sep 26, when the average high is 81°F or warmer. Highs peak around Aug 8 at about 83°F.
- Cool seasonNov 28 – Feb 27 · highs 64°F or lower
The cool season runs from Nov 28 to Feb 27, when the average high is 64°F or lower. The coldest nights come around Dec 8, with an average low near 39°F.
- Rainy seasonNov 13 – Apr 8 · 83% of the year's rain
The rainy season runs from Nov 13 to Apr 8, when a day has at least a 20% chance of measurable rain. That stretch brings 83% 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 1 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, Rancho San Antonio averaged 18 days a year at 90°F or hotter and no freezing nights. It averaged 13 days a year with at least half an inch of rain and 1 afternoon with wind of 20 mph or more at 2 PM. About 53 mornings a year had 3 or more hours of fog or low cloud.
In the same record, the hottest day was Jun 11, 2026 (100°F) and the coldest night was Jan 10, 2026 (35°F). The wettest day was Feb 5, 2025 (1.78 in.), and the strongest 2 PM gust was 53 mph on Mar 12, 2025.
- 18days at 90°F or hotter
- 0nights at or below freezing
- 13days with ½ in. of rain or more
- 1afternoon with 20+ mph wind
- 53mornings with 3+ hours of fog or low cloud
- Hottest day100°FJun 11, 2026
- Coldest night35°FJan 10, 2026
- Wettest day1.78 inFeb 5, 2025
- Strongest 2 PM gust53 mphMar 12, 2025
What shapes Rancho San Antonio's weather
Elevation changes the day quickly at Rancho San Antonio. The Stephen E. Abbors Trail alone gains about 1,600 feet on its way up Black Mountain, and the upper slopes are open chaparral and grass that bake on summer afternoons. From the top you look west toward the coast. On summer evenings you can sometimes watch fog roll in and break over Skyline Ridge while this side stays clear.
Down in Wildcat Canyon the creek bottom stays cool and shaded even on hot days. Winter rain follows the terrain here. The valley floor lies in the rain shadow of the Santa Cruz Mountains. That is the drier zone downwind of the range, where storms have already dropped much of their rain. Rainfall climbs with elevation, so the upper preserve gets noticeably wetter storms than Cupertino or Mountain View below.
Fall can bring some of the valley edge's hottest, driest days. When dry wind blows from the interior toward the ocean, the cooling sea breeze disappears and temperatures can soar. Those same conditions bring Red Flag Warnings, the weather service's alerts for high fire danger. The district closes the model aircraft field when one is in effect.
Tips for visiting Rancho San Antonio
Check parking before you leave
The lots fill at busy times. The district posts live space counts online and on an electronic sign at the entrance gate, and suggests Picchetti Ranch or Fremont Older when Rancho is crowded.
Ride the Hopper from Caltrain
Silicon Valley Hopper, an on-demand shared ride, runs to Rancho from anywhere in Cupertino and from the Mountain View, Sunnyvale and Santa Clara Caltrain stations.
Carry plenty of water uphill
Drinking water isn't available at most of the district's preserves. It recommends two quarts per person for every two hours of hiking, which matters on the sunny Black Mountain climb.
Leave the dog at home
Dogs aren't allowed in Rancho San Antonio Preserve. Service dogs are the only exception.
Watch the trail on warm days
Rattlesnakes are especially active in warm weather, and poison oak and ticks are common in the preserve, so stay on the trail and watch where you step.
Rancho San Antonio through the seasons
- Spring (March–May)
- Lupine, poppies and blue-eyed grass bloom in the meadows along the Wildcat Loop. It is the best season for the Black Mountain climb, before the chaparral heats up.
- Summer (June–August)
- Gray mornings can give way to hot, sunny afternoons on the upper trails, with a breeze at the trailheads. Climb early and save the shaded canyon for midday.
- Fall (September–November)
- Offshore wind events, which the National Weather Service says are most common in fall, can bring some of the year's hottest, driest days to the valley edge. Clear days afterward give long views.
- Winter (December–February)
- Winter is the rainy season. Creeks run in the canyons, and the Hammond-Snyder Loop and Quarry trails can close to horses in wet conditions.
Activities and the weather that matters
- Hiking to Black Mountain: Best on clear, cool spring and fall days. Summer afternoons are hot on the exposed chaparral, and the summit is windy when the sea breeze is up.
- Family walks to Deer Hollow Farm: This mostly level walk from the county park lots works most of the year. Morning visits beat the afternoon heat in summer.
- Trail running the Wildcat Loop: The three-mile loop follows a cool, fern-walled canyon before climbing to open meadows, so even warm days are runnable if you start early.
- Flying model airplanes: Calm mornings are best, before the afternoon breeze builds. The model aircraft area closes during Red Flag Warnings.
Official sources and current conditions
- Midpen: Rancho San Antonio Preserve
- Midpen: Rancho San Antonio live parking availability
- Caltrain: Mountain View station
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 | 84 | 64.2° / 45.9° | 6.7h | 1d | 2.32" | 23 |
| December 2024 | 78 | 62.2° / 45.3° | 5.5h | 4d | 3.44" | 14 |
| January 2025 | 86 | 61.3° / 41.4° | 7.2h | 2d | 0.05" | 23 |
| February 2025 | 81 | 62.9° / 44.4° | 7.1h | 1d | 5.58" | 17 |
| March 2025 | 87 | 64° / 45.4° | 8.7h | 1d | 2.25" | 25 |
| April 2025 | 93 | 69.8° / 47.8° | 9.7h | 0d | 0.43" | 26 |
| May 2025 | 96 | 77.4° / 50.9° | 12.2h | 0d | 0.05" | 31 |
| June 2025 | 95 | 78.3° / 53.3° | 12.6h | 2d | 0" | 30 |
| July 2025 | 94 | 79.6° / 57° | 11.9h | 5d | 0" | 31 |
| August 2025 | 91 | 83.5° / 58° | 11.1h | 8d | 0" | 31 |
| September 2025 | 92 | 81.6° / 60.6° | 9.9h | 3d | 0.18" | 29 |
| October 2025 | 91 | 74° / 53.3° | 8.2h | 3d | 1.47" | 29 |
| November 2025 | 81 | 65.8° / 49.1° | 6.6h | 9d | 3.47" | 17 |
| December 2025 | 77 | 59.9° / 44.6° | 5.6h | 7d | 3.2" | 14 |
| January 2026 | 83 | 62.9° / 44° | 6.7h | 2d | 3.37" | 23 |
| February 2026 | 81 | 65.4° / 46.7° | 6.8h | 2d | 4.19" | 20 |
| March 2026 | 95 | 78.1° / 51.2° | 9.7h | 0d | 0" | 30 |
| April 2026 | 90 | 70° / 49.6° | 9.1h | 0d | 2.55" | 25 |
| May 2026 | 93 | 74.7° / 52.5° | 11.4h | 2d | 0.22" | 31 |
| June 2026 | 94 | 80.9° / 56.2° | 12.3h | 1d | 0" | 29 |
| July 2026 | 94 | 82° / 57.5° | 11.6h | 0d | 0" | 31 |
| August 2026 | 92 | 81.8° / 58.2° | 11h | 5d | 0" | 31 |
| September 2026 | 95 | 80.8° / 55.9° | 10.2h | 2d | 0.05" | 29 |
| October 2026 | 90 | 78° / 53.7° | 8.2h | 3d | 0.11" | 27 |
Climate Trends
Average Temperature by Month
About the Rancho San Antonio climate charts
The temperature chart compares average monthly highs and lows at Rancho San Antonio, 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 Rancho San Antonio. 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 Rancho San Antonio, the warmest typical hour is 3 PM in August (83°F). The coldest is 7 AM in January (46°F).
- Fog: Fog or low cloud covers Rancho San Antonio in 29% of 8 AM hours in August, the foggiest month. It usually thins to a third of that by 10 AM. April mornings are the least foggy (6%).
- Wind: From February through October, wind at Rancho San Antonio typically builds after noon. In June it peaks around 3 PM, averaging 10 mph, while mornings average 4 mph.
- Cloud Cover: July middays are the clearest at Rancho San Antonio (10% average cloud cover), and December middays are the cloudiest (31%).
- Solar Radiation: The strongest typical sun at Rancho San Antonio comes at 1 PM in July, averaging 983 W/m².
How to read the hourly heatmaps for Rancho San Antonio
This heatmap shows how average temperature at Rancho San Antonio 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 Rancho San Antonio. 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 Rancho San Antonio 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 Rancho San Antonio 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 Rancho San Antonio 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 Rancho San Antonio
- October 2026 recap: October 2026 at Rancho San Antonio averaged a high of 78°F, 1°F warmer than the 1991-2020 normal of 77°F. It brought 0.11 in. of rain, compared with a normal of 0.96 in.
- Rain year: The 2025-26 rain year (Oct. 1 to Sep. 30) brought 18.5 in. of rain to Rancho San Antonio, 78% of the 23.8 in. normal.
Location Details
Rancho San Antonio weather questions
Everything you need to know about weather and visiting Rancho San Antonio
What is the weather like at Rancho San Antonio today?
It's 53°F at Rancho San Antonio right now, with a comfort score of 76 (great). Monday's forecast high at Rancho San Antonio is 56°F, 10°F below the mid November normal of 66°F. The best window today is 8 AM to 11 AM, at about 56°F with a 7 mph wind (comfort 60).
What is the best month to visit Rancho San Antonio?
By typical temperature, wind, cloud, humidity, and rain odds, the most comfortable months at Rancho San Antonio are September, July, and June. The best hours are usually 10 AM to 1 PM in September, 9 AM to noon in July, and 10 AM to 1 PM in June. The warm season lasts about 3 months, from Jun 28 to Sep 26, when the average high is 81°F or warmer. Highs peak around Aug 8 at about 83°F.
What are the warmest and coldest months at Rancho San Antonio?
August is the warmest month at Rancho San Antonio, with an average high of 83°F. December is the coldest, with an average low of 39°F.
When does the fog burn off at Rancho San Antonio?
Fog or low cloud covers Rancho San Antonio in 29% of 8 AM hours in August, the foggiest month. It usually thins to a third of that by 10 AM. April mornings are the least foggy (6%).
When is it windiest at Rancho San Antonio?
From February through October, wind at Rancho San Antonio typically builds after noon. In June it peaks around 3 PM, averaging 10 mph, while mornings average 4 mph.
How much rain does Rancho San Antonio get?
February is the wettest month (4.8 in.), out of about 23.8 in. a year. The rainy season runs from Nov 13 to Apr 8, when a day has at least a 20% chance of measurable rain. That stretch brings 83% of the year's rain. The 2025-26 rain year (Oct. 1 to Sep. 30) brought 18.5 in. of rain to Rancho San Antonio, 78% of the 23.8 in. normal.
Can I bring my dog to Rancho San Antonio?
No. The open space district does not allow dogs in Rancho San Antonio Preserve, apart from service dogs. The district keeps a list of preserves that do allow leashed dogs on its Dog Access page.
What kind of place is Rancho San Antonio?
Rancho San Antonio joins a 2,180-acre open space preserve to a 293-acre Santa Clara County park at the end of Cristo Rey Drive in Cupertino. It sits right where the foothills rise off the valley floor. The Midpeninsula Regional Open Space District manages both, with more than 25 miles of trail. Most visitors stay low, around Deer Hollow Farm and the fern-lined Wildcat Canyon loop. The Black Mountain Trail climbs about four miles through chaparral and oak to a 2,800-foot summit above Stevens Creek Canyon.
What is Rancho San Antonio weather like in November?
November at Rancho San Antonio averages a high of 66°F and a low of 42°F, with 2.3 in. of rain over about 6 rainy days. Afternoon wind averages 6 mph.
More about Rancho San Antonio 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.
- Midpeninsula Regional Open Space District, Rancho San Antonio Preserve (accessed 2026-10-27)
- Midpeninsula Regional Open Space District, Rancho San Antonio Parking (accessed 2026-10-27)
- National Weather Service, Climate of San Jose (NOAA Technical Memorandum NWS WR-259) (accessed 2026-10-27)
Rendered 2026-11-15T12:16:29.570Z.