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Official National Weather Service (NWS) point forecast and real-time wind conditions for Thermalito Afterbay (California). 24-hour hour-by-hour wind timelines, peak gusts, watercraft recreation safety thresholds, and 7-day marine outlook.
Today: High 73°F · Low 47°F
Peak gusts: 8 mph · Lake surface chop expected
Humidity: 40% · Barometer: 29.78 inHg
Live hydrological sensor reading for Thermalito Afterbay.
Excellent for boating (98/100), from 4 available inputs. Supporting this: Wind 3 mph from the east-southeast. Gusts to 7 mph. Not available from a verified source for this lake: visibility and conditions, verified water access. Confidence is moderate (84%) because some inputs are unavailable or older than ideal.
Good for fishing (89/100), from 6 available inputs. Supporting this: Measured water temperature 61°F from a representative gauge 17.5 mi away. Provisional data. Wind 3 mph from the east-southeast. Not available from a verified source for this lake: pressure trend. Confidence is moderate (72%) because some inputs are unavailable or older than ideal.
Excellent for kayaking (98/100), from 5 available inputs. Supporting this: Wind 3 mph from the east-southeast. Gusts to 7 mph. Confidence is high (90%).
Fair for swimming (73/100), from 5 available inputs. Supporting this: No active official alerts for this lake. 0% chance of precipitation. Working against it: Measured water temperature 61°F from a representative gauge 17.5 mi away. Provisional data. Confidence is moderate (75%) because some inputs are unavailable or older than ideal.
| Time | Air Temp | Wind (mph) | Direction | Peak Gusts | Rain Chance | Sky & Conditions |
|---|---|---|---|---|---|---|
| 9 PM | 62°F | 3 mph | SE | ⚡ 7 mph | 0% | Clear |
| 10 PM | 60°F | 2 mph | SE | ⚡ 6 mph | 0% | Clear |
| 11 PM | 59°F | 2 mph | SE | ⚡ 5 mph | 0% | Mostly Clear |
| 12 AM | 57°F | 1 mph | SE | ⚡ 4 mph | 0% | Clear |
| 1 AM | 55°F | 0 mph | — | ⚡ 2 mph | 0% | Clear |
| 2 AM | 54°F | 0 mph | — | ⚡ 2 mph | 0% | Clear |
| 3 AM | 52°F | 1 mph | N | ⚡ 4 mph | 0% | Clear |
| 4 AM | 50°F | 1 mph | NW | ⚡ 4 mph | 0% | Clear |
| 5 AM | 49°F | 2 mph | N | ⚡ 6 mph | 0% | Clear |
| 6 AM | 48°F | 2 mph | N | ⚡ 6 mph | 0% | Sunny |
| 7 AM | 47°F | 3 mph | N | ⚡ 6 mph | 0% | Sunny |
| 8 AM | 49°F | 5 mph | NW | ⚡ 13 mph | 0% | Sunny |
| 9 AM | 53°F | 8 mph | NW | ⚡ 16 mph | 0% | Sunny |
| 10 AM | 61°F | 10 mph | NW | ⚡ 20 mph | 0% | Sunny |
| 11 AM | 65°F | 10 mph | NW | ⚡ 21 mph | 0% | Sunny |
| 12 PM | 68°F | 10 mph | NW | ⚡ 20 mph | 0% | Sunny |
| 1 PM | 72°F | 9 mph | NW | ⚡ 18 mph | 0% | Sunny |
| 2 PM | 73°F | 9 mph | NW | ⚡ 17 mph | 0% | Sunny |
| 3 PM | 74°F | 8 mph | W | ⚡ 16 mph | 0% | Sunny |
| 4 PM | 75°F | 7 mph | W | ⚡ 15 mph | 0% | Sunny |
| 5 PM | 73°F | 5 mph | S | ⚡ 10 mph | 0% | Sunny |
| 6 PM | 73°F | 5 mph | S | ⚡ 10 mph | 1% | Clear |
| 7 PM | 69°F | 5 mph | S | ⚡ 10 mph | 0% | Clear |
| 8 PM | 63°F | 5 mph | SE | ⚡ 9 mph | 0% | Mostly Clear |
Mirror-like to gentle rippled water. Optimal conditions for paddleboarding, kayaking, swimming, and beginner water skiing or wakeboarding.
Pleasant breeze with small wavelets. Great for sailing, pleasure cruising, pontoon boats, and trolling for trout and bass.
Moderate waves with whitecaps likely. Requires skilled boat handling; kayaks, canoes, and stand-up paddleboards should stay close to sheltered bays.
Steep waves, cold spray, and hazardous open water. Avoid small craft voyages. Always check official National Weather Service lake wind advisories.
Clear. Low around 47, with temperatures rising to around 49 overnight. East northeast wind 0 to 3 mph.
Sunny. High near 75, with temperatures falling to around 73 in the afternoon. West northwest wind 2 to 10 mph, with gusts as high as 21 mph.
Mostly clear. Low around 49, with temperatures rising to around 51 overnight. East southeast wind around 6 mph.
Sunny, with a high near 69. Southwest wind around 6 mph.
Mostly clear, with a low around 43. Northeast wind around 3 mph.
Sunny, with a high near 75.
Clear, with a low around 46.
Sunny, with a high near 79.
Clear, with a low around 50.
Sunny, with a high near 84.
Clear, with a low around 52.
Sunny, with a high near 84.
Mostly clear, with a low around 53.
Sunny, with a high near 85.
Thermalito Afterbay currently reports 69°F with wind velocity near 5 mph from the SE. Atmospheric forecasts and 24-hour hour-by-hour wind timelines are updated hourly from the National Weather Service gridpoint matching the lake's coordinates.
At Thermalito Afterbay and surrounding mountain valleys, diurnal heating of the surrounding terrain causes strong thermal pressure differentials known locally as afternoon breezes (such as the Washoe Zephyr at Lake Tahoe). Wind speeds typically peak between 1:00 PM and 5:00 PM before calming near sunset.
For stand-up paddleboarding (SUP), canoeing, and light kayaks, winds under 7 mph (light breeze) offer the safest, glassiest surface conditions. Between 8–14 mph, small wavelets develop, suitable for sailboats and powerboats. Winds exceeding 15 mph create steep whitecaps and rapid drift; winds over 21 mph warrant small craft warnings.
All weather and wind telemetry is fetched directly from the National Weather Service (NOAA - WFO STO) high-resolution numerical point-forecast API. LakeRadar uses the official gridpoint for Thermalito Afterbay without artificial smoothing or third-party estimates.
Yes. Live hydrological sensor readings, 30-day elevation histories, full-pool benchmarks, and USGS station provenance are available on our dedicated Thermalito Afterbay Water Level & Temperature page.
View Thermalito Afterbay Water Level & Temperature →