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Official National Weather Service (NWS) point forecast and real-time wind conditions for Helena Valley Reservoir (Montana). 24-hour hour-by-hour wind timelines, peak gusts, watercraft recreation safety thresholds, and 7-day marine outlook.
Red Flag Warning issued October 9 at 11:53AM MDT until October 9 at 9:00PM MDT by NWS Great Falls MT
Today: High 82°F · Low 46°F
Peak gusts: 16 mph · Lake surface chop expected
Humidity: 27% · Barometer: 29.90 inHg
USGS water monitoring available for Helena Valley Reservoir.
Red Flag Warning issued October 9 at 11:53AM MDT until October 9 at 9:00PM MDT by NWS Great Falls MT
Fair for boating (62/100), from 4 available inputs. Supporting this: Wind 10 mph from the southwest. 0% chance of precipitation. Working against it: Active severe alert: Red Flag Warning. 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 (84/100), from 5 available inputs. Supporting this: Wind 10 mph from the southwest. 0% chance of precipitation. Not available from a verified source for this lake: pressure trend, water temperature. Confidence is moderate (74%) because some inputs are unavailable or older than ideal.
Fair for kayaking (65/100), from 5 available inputs. Supporting this: Wind 10 mph from the southwest. 0% chance of precipitation. Working against it: Active severe alert: Red Flag Warning. Confidence is high (90%).
Water temperature is not available from a verified source for this lake. No swimming score is shown without it. Supporting this: 0% chance of precipitation. Wind 10 mph from the southwest. Working against it: Active severe alert: Red Flag Warning. Not available from a verified source for this lake: water temperature.
| Time | Air Temp | Wind (mph) | Direction | Peak Gusts | Rain Chance | Sky & Conditions |
|---|---|---|---|---|---|---|
| 12 PM | 72°F | 10 mph | SW | ⚡ 20 mph | 0% | Sunny |
| 1 PM | 76°F | 14 mph | SW | ⚡ 23 mph | 0% | Sunny |
| 2 PM | 80°F | 17 mph | W | ⚡ 29 mph | 0% | Sunny |
| 3 PM | 81°F | 20 mph | W | ⚡ 32 mph | 0% | Sunny |
| 4 PM | 82°F | 18 mph | W | ⚡ 33 mph | 0% | Sunny |
| 5 PM | 80°F | 16 mph | W | ⚡ 31 mph | 0% | Sunny |
| 6 PM | 77°F | 14 mph | NW | ⚡ 28 mph | 0% | Mostly Clear |
| 7 PM | 72°F | 12 mph | W | ⚡ 22 mph | 0% | Partly Cloudy |
| 8 PM | 63°F | 9 mph | W | ⚡ 17 mph | 0% | Partly Cloudy |
| 9 PM | 59°F | 7 mph | W | ⚡ 13 mph | 0% | Partly Cloudy |
| 10 PM | 56°F | 7 mph | W | ⚡ 12 mph | 0% | Mostly Cloudy |
| 11 PM | 54°F | 7 mph | NW | ⚡ 13 mph | 0% | Mostly Cloudy |
| 12 AM | 52°F | 7 mph | NW | ⚡ 12 mph | 1% | Mostly Cloudy |
| 1 AM | 50°F | 6 mph | NW | ⚡ 9 mph | 1% | Cloudy |
| 2 AM | 48°F | 6 mph | NW | ⚡ 8 mph | 2% | Cloudy |
| 3 AM | 47°F | 5 mph | NW | ⚡ 7 mph | 2% | Cloudy |
| 4 AM | 46°F | 5 mph | NW | ⚡ 7 mph | 3% | Cloudy |
| 5 AM | 46°F | 5 mph | NW | ⚡ 7 mph | 4% | Cloudy |
| 6 AM | 46°F | 5 mph | NW | ⚡ 7 mph | 16% | Cloudy |
| 7 AM | 46°F | 6 mph | NW | ⚡ 8 mph | 18% | Cloudy |
| 8 AM | 47°F | 7 mph | NW | ⚡ 9 mph | 27% | Slight Chance Light Rain |
| 9 AM | 47°F | 8 mph | NW | ⚡ 12 mph | 54% | Slight Chance Light Rain |
| 10 AM | 47°F | 9 mph | NW | ⚡ 15 mph | 49% | Chance Light Rain |
| 11 AM | 46°F | 12 mph | N | ⚡ 18 mph | 49% | Chance Rain |
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.
Sunny, with a high near 82. Southwest wind 9 to 20 mph, with gusts as high as 33 mph.
Mostly cloudy. Low around 41, with temperatures rising to around 46 overnight. West northwest wind 5 to 14 mph, with gusts as high as 28 mph.
Rain after 8am. Cloudy. High near 55, with temperatures falling to around 35 in the afternoon. Northwest wind 5 to 22 mph, with gusts as high as 31 mph. Chance of precipitation is 90%. New rainfall amounts between a tenth and quarter of an inch possible.
Rain before 9pm, then snow. Cloudy, with a low around 25. North northwest wind 16 to 22 mph, with gusts as high as 40 mph. Chance of precipitation is 100%. New snow accumulation of 1 to 3 inches possible.
Snow. Cloudy, with a high near 35. North northwest wind 12 to 16 mph, with gusts as high as 26 mph. Chance of precipitation is 100%. New snow accumulation of 1 to 3 inches possible.
Snow before 9pm, then rain and snow. Cloudy, with a low around 23. North northwest wind 8 to 13 mph, with gusts as high as 23 mph. Chance of precipitation is 90%. New snow accumulation of less than one inch possible.
A chance of snow before 9am, then a chance of rain and snow. Mostly cloudy, with a high near 43. Northwest wind 1 to 5 mph.
Mostly cloudy, with a low around 25. Southwest wind around 2 mph.
Partly sunny, with a high near 53.
Partly cloudy, with a low around 29.
A slight chance of rain after noon. Partly sunny, with a high near 57.
A chance of rain before 3am, then a chance of rain and snow. Mostly cloudy, with a low around 30.
A chance of rain and snow. Partly sunny, with a high near 54.
Partly cloudy, with a low around 26.
Helena Valley Reservoir currently reports 70°F with wind velocity near 2 mph from the NW. 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 Helena Valley Reservoir 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 TFX) high-resolution numerical point-forecast API. LakeRadar uses the official gridpoint for Helena Valley Reservoir 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 Helena Valley Reservoir Water Level & Temperature page.
View Helena Valley Reservoir Water Level & Temperature →