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Sherman Island
California · San Francisco Bay · Sacramento County · Rio Vista
also known as Sherman Lake, Rio Vista Delta, The Delta, Rio
Riding essentials
Season
May–Sep
Months riders and schools name
How windy
15-25 kt
Character: thermal · onshore
Room to launch
tight
access rules on record, below
Water
mixed
22 °C in summerCounty Park riding mixes flat water, muddy shallows, chop, and ebb-tide river swell
Hazards
25
Reported by riders
Level
Intermediate to advanced
With a caveat: see Your level
Crowds
high crowds · busy Jun Jul Aug
Schools
5
named at this spot
From the airport
International Airport (SMF)
Transfer times under Getting there
When it fills in
There is no single clock here. The most common summer pattern is wind overnight and at dawn, a mid-day fade, then a rebuild through the late afternoon that can hold past sunset. Some days it simply blows straight through from the night before. Others start light, die completely, and only fill in late. If you get one window, take the afternoon.
Nearbystraight-line distance
Backup spotsWhere riders go when the wind doesn't work here.
- Brannan Island State Recreation Areano page yet
- Sherman Island / Team Rio Beachno page yet
- Sherman Island / Powerlinesno page yet
- Sherman Island / Cable Crossingno page yet
- Sherman Lake Marinano page yet
- Brannan Island / Windy Coveno page yet
The spot
The Delta
Water and river
Learning and staying
The wind
locals call it Delta breeze / Rio Daze thermal
Direction
Kite sizes
metres · typical quiver highlighted
The quiver, in words
A 75-85 kg rider is on 9 m for the standard 18-22 kt summer thermal and 7-8 m when a strong cool-down day pushes into the high 20s. Keep an 11-12 m for early season, shoulder months and the light morning window. Most locals bring two kites and change size as the afternoon builds.
Character
Average strength
15-25
Typical strength
15-25 kt on established summer thermal days; stronger cool-down days can reach the upper 20s to low 30s mph.
Forecast
Live forecast
Month by month
- Jan23
- Feb21
- Mar29
- Apr33
- May, riders' month58
- Jun, riders' month78
- Jul, riders' month69
- Aug, riders' month56
- Sep, riders' month35
- Oct10
- Nov8
- Dec5
windy days per month (3 h+ at 12 kn+)
Ringed months are the ones riders and schools name: May, Jun, Jul, Aug, Sep.
- 23%Jan
- 21%Feb
- 29%Mar
- 33%Apr
- 58%May
- 78%Jun
- 69%Jul
- 56%Aug
- 35%Sep
- 10%Oct
- 8%Nov
- 5%Dec
windy days per month (3 h+ at 12 kn+) · season highlighted
Modelled from the operational forecast archive at 1.5–7 km (2023-2024), daylight hours only, not a ground station: it resolves thermal, lake and valley winds far better than coarse reanalysis but still tends to understate a strong local thermal.
Every figure, month by monthWindy days · Force 4+ · 12 kn or more · Knots · Wind from · Peaks at · Air · Readings
| Month | Windy days | Force 4+ | 12 kn or more | Knots | Wind from | Peaks at | Air | Readings |
|---|---|---|---|---|---|---|---|---|
| Jan | 23% | 44% | 35% | 11.1 kt | SSE | 13:00 | 8.3 °C | 62 |
| Feb | 21% | 44% | 37% | 11.1 kt | WNW | 15:00 | 10.6 °C | 57 |
| Mar | 29% | 60% | 48% | 12.7 kt | WNW | 14:00 | 12.8 °C | 62 |
| Apr | 33% | 62% | 50% | 12 kt | WNW | 17:00 | 15 °C | 60 |
| May | 58% | 97% | 85% | 14.4 kt | WNW | 18:00 | 17.8 °C | 62 |
| Jun | 78% | 95% | 88% | 14.7 kt | WNW | 17:00 | 21.1 °C | 60 |
| Jul | 69% | 98% | 89% | 14.5 kt | WNW | 17:00 | 22.8 °C | 62 |
| Aug | 56% | 92% | 81% | 13.4 kt | WNW | 17:00 | 22.2 °C | 62 |
| Sep | 35% | 73% | 62% | 12.4 kt | WNW | 17:00 | 21.1 °C | 60 |
| Oct | 10% | 35% | 21% | 9.6 kt | WNW | 16:00 | 17.8 °C | 62 |
| Nov | 8% | 32% | 28% | 9.1 kt | WNW | 14:00 | 12.2 °C | 60 |
| Dec | 5% | 18% | 13% | 8.1 kt | SSE | 12:00 | 8.3 °C | 62 |
How this is modelledmodelled · 2023-2024
A weather model's cell over this place, not a station on it. Good for comparing places, weaker for one beach.
A windy day has at least three consecutive daylight hours at 12 knots or more. The typical daily max and the direction are columns of the table above, month by month. Highlighted months are the riding season from the spot record.
High-resolution weather model (modelled) · Open-Meteo historical forecast archive — best-match operational model (ICON-D2 / AROME / ICON-EU / GFS by region), not a ground station · 2023-2024
The water
Type
mixed
Standing depth
You can stand along the beach edge and over the muddy shallows toward Sherman Lake and the marsh islands, but the shelf is narrow. The Sacramento River channel just outside runs around 30 ft deep and roughly 200 ft wide, so once you are off the bank this is not stand-up learning water.Low ebb does not make the shallows safer: it uncovers roots, dead trunks, reeds and rock.
Tides
Tidal Delta water, and the two halves of the cycle ride completely differently. Flood flattens the surface and is the friendly half. Ebb builds 1-3 ft of chop and swell, gives good ramps, and drops the water enough to expose debris in the shallows.Read the tide table before you rig, not after you launch.
Temperature
22 °C summer · 10 °C winter
Wetsuit
Boardshorts or a rashguard on hot summer days, a shorty in spring, and a 3 mm full suit for most of the rest of the season. What the winter regulars actually wear here is unconfirmed.
Currents
Strong flood and ebb through the whole reach, with peaks near 0.9-1.3 kt on a late-August 2026 cycle.Flood pushes riders up-river and into the shipping channel. Ebb sets the other way toward Suisun Bay, which is open, empty water once you are past the launches.Current near Team Rio and the Access beaches is reported to be gentler than elsewhere on the island.
Conditions
Your level
not for beginners here
The scene
What riders come here for
Launch and rules
three ways on to the water, and what each one asks of you
With a school or a boat
5 schools name this spot
On your own
Room to launch: tight
Somewhere else
5 spots nearby
Rescue
VHF 16
Rescue — full text1 min read
Launch
Rig in the meadow near the road at the County Park Upper Kite Launch, which is the main kite area, then use the dedicated one-way path down through the blackberries to the beach. Take turns, keep the sand clear, and walk out far enough that you can head upwind straight away.Lower Launch and foilersA Lower Kite Launch sits nearby: it is small and often crowded, so skip it on busy days. A third, two-way path is used by foilers.Parking and playpenThe playpen area is an emergency exit, not a place to session. Parking on the levee is forbidden because of how fragile the levee system is.
Rules & access
1 min read
Launch restrictions
Launch etiquette
Membership
Drones and wildlife
Access rules drift faster than anything else we hold — check locally, and propose an edit if this has changed.
Schools that ride here
Rider tips
- Read the tide and current tables before you rig, not after you launch: flood flattens the water, ebb builds 1-3 ft of chop and uncovers roots, trunks and rock.
- Bring cash or a card for the gate: $8 per vehicle in 2026, and use the on-site RV camping if you are staying several days.
- Rig in the meadow, carry the board down to the beach first, take the one-way path, and get away from shore as soon as you are up.
- No jumping or tricks within 200 ft of the beaches and shore areas, and never leave lines unwound across the path.
- A 3 mm full suit covers most of the season, with a shorty on the hottest days; the water sits near 22 C in July and August and drops near 10 C by mid-December.
- If you are still learning to ride upwind, book a lesson or a boat-supported downwinder instead of self-launching from the public beach.
- Join the Rio Vista Windsports Association, $25 for an individual in 2026: that money is the sandbags and the toilets you are about to use.
- Ask somebody before your first session. The path etiquette and the launch hazards are not obvious from the car park.
Getting there
Airport
Sacramento International Airport (SMF) is the closest major airport commonly used for Rio Vista; Oakland (OAK) and San Francisco (SFO) are also practical Bay Area options.
Route
By car from Sacramento, the route runs via Highway 50/I-5/Highway 12 to Highway 160, then south on Sherman Island Road into the park. From San Francisco: cross the Bay Bridge, head through Walnut Creek/Concord/Antioch, take Highway 160 over Antioch Bridge, then turn left on West Sherman Island Road.
Transfer
About 60-75 minutes from SMF to Rio Vista; about 1-2 hours from San Francisco depending on origin and traffic.
Cost level
medium
Staying
On-site County Park camping is limited to self-contained RVs/trailers/vans with a 14-night maximum and 30-day break. Nearby Delta options include Sherman Lake Marina and Rio Viento RV Park; hotels are reported in Antioch and Rio Vista rather than at the launch.
No-wind days
Wildlife viewing and birdwatching in Lower Sherman Island Wildlife Area, fishing for salmon/steelhead/striped bass/sturgeon, boating/kayaking, photography, Delta drives, or day trips to Antioch/Rio Vista.
Photos
FAQ
When is the best time to kite?
The windy season runs roughly May through August, driven by cool coastal air pulled toward the hot Central Valley, producing steady 15-25 knot southwest to west-southwest wind most afternoons.
Is Sherman Island suitable for beginners?
Independent beginners should not treat the public County Park launch as a beginner spot; the wind blows directly onshore and the launch area is tight, though schools use boat and radio support for lessons.
What are the tidal currents like?
Currents are strong in the Delta, with flood tides giving flatter water and ebb tides producing 1-3 foot chop and stronger apparent upwind flow, so tide and current should be checked before rigging.
Are there rules or fees?
As of 2026, Sherman Island County Park charges $8 per vehicle and is open year-round sunrise to sunset; County Park launches are the only approved kite launches on the island.
The bigger pictureEverything about San Francisco Bay
Last updated: August 2026