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Sherman Island
Sherman Island is a low-lying island in the Sacramento-San Joaquin River Delta, about 1.2 miles northeast of Antioch, California, and one of the most famous kiteboarding and windsurfing venues in Northern California. It owes its reputation to exceptionally reliable summer afternoon thermal winds funneled through the Delta as hot Central Valley air draws in cooler marine air from San Francisco Bay. The main riding area, Sherman Lake within the Lower Sherman Island Wildlife Area, offers flat, sheltered water in a remote, rural wetlands setting rather than an ocean beach.
freeridefreestyleflat waterfoilbeginner
Wind
| best months |
|
|---|---|
| season notes | Classic Delta thermal pattern: wind is driven by the temperature difference between the hot Central Valley and cooler coastal/Bay air, so it typically fills in by late morning to early afternoon and can hold into evening on the strongest days. Peak reliability is June through August; spring and early fall can also produce good thermal days but are less consistent. |
| avg knots | 15-25 |
| wind name | Delta breeze (thermal) |
| direction to shore | Cross-shore, generally out of the west/southwest across Sherman Lake |
| quality | thermal, generally steady once established but can be gusty near the channel |
| typical kite sizes | 7-12m |
Water
| type | flat, lake-like marsh/channel water |
|---|---|
| wetsuit | Boardshorts/rashguard typical in peak summer; a shorty or light steamer is common in the cooler shoulder season |
| currents | Adjacent Delta channels carry boat traffic and current; the main lake area is more protected |
| standing depth | Yes in sections of Sherman Lake, which helps make parts of it approachable for less experienced riders |
Levels
| beginner | yes |
|---|---|
| intermediate | yes |
| advanced | yes |
| notes | Sherman Lake's flat, shallow sections suit progressing riders and freestyle/foil practice, while stronger thermal days and the open channel areas favor experienced kiters. |
Launch & crowd
| description | Rig and launch from the shoreline of the Sherman Island County Park / Lower Sherman Island Wildlife Area day-use area, which has open grass/dirt space for setup |
|---|---|
| rescue | No formal rescue service reported; self-rescue and a buddy system are standard practice |
| busy months |
|
| vibe | Laid-back, rural/agricultural setting popular with Bay Area and Sacramento windsurfers and kiters; tight-knit local scene rather than a tourist beach |
Monthly wind statistics
Station: Rio Vista, CA (Weatherspark (NASA MERRA-2 reanalysis), ~8 km) — Windfinder has a dedicated 'sherman_island_delta' windstatistics page but it is JS-rendered with no numbers in static HTML and the live site 429'd on all fetch attempts (its stats API needs an undisclosed auth token). Used Weatherspark MERRA-2 reanalysis for nearby Rio Vista (~8km NE, same Sacramento-San Joaquin Delta wind regime) as fallback. No water temperature shown for this inland river location. No Beaufort-probability metric available from this source.
| Month | Wind ≥4 Bft | Avg kn | Dir | Air °C | Water °C |
|---|---|---|---|---|---|
| Jan | —% | 5.5 | N | 8.3 | — |
| Feb | —% | 5.8 | N | 10.6 | — |
| Mar | —% | 6.2 | W | 12.8 | — |
| Apr | —% | 6.7 | W | 15 | — |
| May | —% | 7.5 | W | 17.8 | — |
| Jun | —% | 8 | W | 21.1 | — |
| Jul | —% | 8.2 | W | 22.8 | — |
| Aug | —% | 7.6 | W | 22.2 | — |
| Sep | —% | 6.6 | W | 21.1 | — |
| Oct | —% | 5.6 | W | 17.8 | — |
| Nov | —% | 5.5 | N | 12.2 | — |
| Dec | —% | 5.7 | N | 8.3 | — |
Hazards
- Wind can build quickly and strongly once the Delta thermal fills in
- Boat and jet-ski traffic in the surrounding Delta waterways
- Muddy/marshy bottom in places
- Levees and riprap along parts of the shoreline - keep clear
- Remote location with no lifeguards
Rules
- Sherman Island County Park day-use area charges a vehicle entrance fee (about $7 as of 2026)
- Park hours are sunrise to sunset year-round
- On-site RV camping available for a separate nightly fee (about $35/night, max 14 nights)
Tips
- Access via CA-160 across the Antioch Bridge, or by boat
- Bring cash/card for the vehicle day fee and consider the on-site RV camping if staying multiple days
- Afternoon is the reliable window for the thermal to fill in
Travel basics
| airport | SFO or OAK (San Francisco Bay Area, roughly 1-1.5 hrs) or SMF (Sacramento, roughly 1 hr) |
|---|---|
| getting there | Drive via CA-160 through the Delta to Sherman Island County Park near Antioch |
| accommodation | No hotels on the island itself besides RV camping; most riders day-trip from the Bay Area or Sacramento, or stay in nearby Antioch/Rio Vista |
| cost level | budget |
| no wind | Explore the Delta waterways and towns like Rio Vista, or head back into the Bay Area or Sacramento |
Nearby: Brannan Island State Recreation Area
Sources: en.wikipedia.org · en.wikipedia.org