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Saint Mary Lake is a natural lake located in Montana.
Updated
Latest source update is older than expected. Use caution and check the official source.
The last automated check (Oct 9, 2:32 AM MDT) found no active alerts for this lake, but that check is older than LakeRadar's alert freshness window, so the current alert status could not be confirmed.
Confirm before heading out: official alerts for this area or weather.gov/alerts. LakeRadar scores summarize available conditions and are not a substitute for official warnings, local rules, or on-water judgment.
Overall Fair (65/100) across 4 activities. Best right now: Sailing (73/100).
How the score is calculated →Best fair fishing window, averaging 73/100 across these hours. Dawn hours (07:00 local). 0% chance of precipitation. Derived from the hourly forecast; official alerts are not forecast and are checked separately.
| Metric | 9a | 10a | 11a | 12p | 1p | 2p | 3p | 4p | 5p | 6p | 7p | 8p | 9p | 10p | 11p | 12a | 1a | 2a | 3a | 4a | 5a | 6a | 7a | 8a |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Temp (°F) | 52° | 52° | 52° | 48° | 49° | 48° | 52° | 56° | 59° | 60° | 62° | 62° | 63° | 61° | 59° | 57° | 53° | 50° | 48° | 46° | 42° | 42° | 40° | 39° |
| Wind (kts) | 16 | 17 | 19 | 20 | 20 | 19 | 19 | 20 | 22 | 22 | 22 | 21 | 22 | 22 | 21 | 19 | 19 | 19 | 18 | 16 | 13 | 10 | 9 | 7 |
| Direction | SW | SW | SW | SW | W | W | W | W | W | W | W | W | W | W | W | W | W | W | W | W | W | W | W | W |
| Gusts (kts) | 35 | 37 | 41 | 41 | 43 | 44 | 43 | 47 | 47 | 46 | 46 | 45 | 45 | 46 | 46 | 45 | 45 | 44 | 43 | 38 | 32 | 24 | 19 | 15 |
| Precip % | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 1% | 1% | 6% | 16% | 49% | 51% | 50% | 20% | 23% | 19% | 30% | 29% | 22% |
| Time | Temp | Wind | Gusts | Precip | Cloud | Condition |
|---|---|---|---|---|---|---|
| Fri, 3 AM MDT | 52°F | 18 mph SW (225°) | 40 mph | 0% | 72% | Mostly Cloudy |
| Fri, 4 AM MDT | 52°F | 20 mph SW (225°) | 43 mph | 0% | 64% | Mostly Cloudy |
| Fri, 5 AM MDT | 52°F | 22 mph SW (225°) | 47 mph | 0% | 57% | Mostly Cloudy |
| Fri, 6 AM MDT | 48°F | 23 mph SW (225°) | 47 mph | 0% | 44% | Mostly Sunny |
| Fri, 7 AM MDT | 49°F | 23 mph WSW (248°) | 50 mph | 0% | 51% | Partly Sunny |
| Fri, 8 AM MDT | 48°F | 22 mph WSW (248°) | 51 mph | 0% | 46% | Mostly Sunny |
| Fri, 9 AM MDT | 52°F | 22 mph WSW (248°) | 50 mph | 0% | 37% | Mostly Sunny |
| Fri, 10 AM MDT | 56°F | 23 mph WSW (248°) | 54 mph | 0% | 33% | Mostly Sunny |
| Fri, 11 AM MDT | 59°F | 25 mph WSW (248°) | 54 mph | 0% | 24% | Sunny |
| Fri, 12 PM MDT | 60°F | 25 mph WSW (248°) | 53 mph | 0% | 16% | Sunny |
| Fri, 1 PM MDT | 62°F | 25 mph WSW (248°) | 53 mph | 0% | 9% | Sunny |
| Fri, 2 PM MDT | 62°F | 24 mph WSW (248°) | 52 mph | 1% | 6% | Sunny |
| Fri, 3 PM MDT | 63°F | 25 mph WSW (248°) | 52 mph | 1% | 9% | Sunny |
| Fri, 4 PM MDT | 61°F | 25 mph WSW (248°) | 53 mph | 6% | 16% | Sunny |
| Fri, 5 PM MDT | 59°F | 24 mph WSW (248°) | 53 mph | 16% | 28% | Slight Chance Light Rain |
| Fri, 6 PM MDT | 57°F | 22 mph WSW (248°) | 52 mph | 49% | 66% | Chance Light Rain |
| Fri, 7 PM MDT | 53°F | 22 mph WSW (248°) | 52 mph | 51% | 67% | Chance Light Rain |
| Fri, 8 PM MDT | 50°F | 22 mph WSW (248°) | 51 mph | 50% | 67% | Chance Light Rain |
| Fri, 9 PM MDT | 48°F | 21 mph WSW (248°) | 50 mph | 20% | 68% | Slight Chance Light Rain |
| Fri, 10 PM MDT | 46°F | 18 mph WSW (248°) | 44 mph | 23% | 64% | Slight Chance Light Rain |
| Fri, 11 PM MDT | 42°F | 15 mph WSW (248°) | 37 mph | 19% | 61% | Slight Chance Light Rain |
| Sat, 12 AM MDT | 42°F | 12 mph WSW (248°) | 28 mph | 30% | 63% | Chance Light Rain |
| Sat, 1 AM MDT | 40°F | 10 mph WSW (248°) | 22 mph | 29% | 59% | Chance Light Rain |
| Sat, 2 AM MDT | 39°F | 8 mph WSW (248°) | 17 mph | 22% | 69% | Slight Chance Light Rain |
| Sat, 3 AM MDT | 40°F | 6 mph WSW (248°) | 14 mph | 23% | 58% | Slight Chance Light Rain |
Official National Weather Service hourly forecast. Showing 10 of 25 hours. Wind arrows point the way the wind is blowing; the compass point and degrees show where it comes from.
| Period | Overnight October 9, 2026 | Friday October 9, 2026 | Friday Night October 9, 2026 | Saturday October 10, 2026 | Saturday Night October 10, 2026 | Sunday October 11, 2026 | Sunday Night October 11, 2026 | Columbus Day October 12, 2026 | Monday Night October 12, 2026 | Tuesday October 13, 2026 | Tuesday Night October 13, 2026 | Wednesday October 14, 2026 | Wednesday Night October 14, 2026 | Thursday October 15, 2026 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Temp (°F) | 45° | 63° | 27° | 40° | 19° | 29° | 19° | 44° | 25° | 48° | 28° | 47° | 28° | 47° |
| Wind | SW 17 to 22 mph | SW 22 to 25 mph | WSW 6 to 22 mph | N 7 to 14 mph | NNE 14 to 18 mph | NE 12 to 18 mph | E 3 to 8 mph | SSW 5 mph | SW 3 to 10 mph | WSW 10 mph | WSW 9 to 18 mph | WSW 12 to 18 mph | NW 10 mph | NNW 7 mph |
| Gusts | 47 mph | 54 mph | 52 mph | 28 mph | 39 mph | 38 mph | 17 mph | 9 mph | 16 mph | 17 mph | 31 mph | 32 mph | 20 mph | 14 mph |
| Precip % | 0% | 16% | 51% | 70% | 99% | 95% | 43% | 8% | 4% | 2% | 8% | 39% | 56% | 27% |
| Forecast |
Fair for fishing (70/100), from 5 available inputs. Supporting this: 0% chance of precipitation. Sky is cloudy (72% cloud cover). 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 boating (59/100), from 4 available inputs. Supporting this: No active official alerts for this lake. 0% chance of precipitation. Working against it: Gusts to 40 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.
Fair for sailing (73/100), from 4 available inputs. Supporting this: Wind 18 mph from the SW is in the preferred sailing range. No active official alerts for this lake. Working against it: Gusts exceed sustained wind by 22 mph, making the breeze puffy. Not available from a verified source for this lake: visibility. Confidence is high (88%).
Fair for kayaking (57/100), from 5 available inputs. Supporting this: No active official alerts for this lake. 0% chance of precipitation. Working against it: Gusts to 40 mph. Confidence is high (90%).
Water temperature is not available from a verified source for this lake. No swimming score is shown without it.
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Individual boat ramp GPS coordinates are maintained under the jurisdiction of MT Parks & Wildlife Authority. Public boaters should verify seasonal launch water levels, gate hours, and daily vehicle/vessel fees before traveling.
In MT, Saint Mary Lake stands as a valued freshwater lake offering scenic outdoor recreation and critical regional water resources. Visitors enjoy powerboating, sailing, and tranquil shoreline fishing across its varied channels. Check state agency updates for current fishing creel limits and aquatic species inspections.
Valid freshwater sport fishing license issued by Montana Fish, Wildlife & Parks (FWP) is required for anglers age 12+. Digital license on mobile is accepted.
Mandatory Clean, Drain & Dry inspection. Out-of-area craft require on-site Aquatic Invasive Species (AIS Quagga/Zebra) inspection or decontamination before launch. USCG life jackets required for all.
Public shoreline and boating access managed by State & Local Authorities. Verify seasonal gate hours, launch fees, and parking rules before travel.
High-speed motorboating, pontoon cruising, wakeboarding, and water skiing across main channels. Target gamefish include Mountain Whitefish, Mackinaw (Lake Trout), Brook Trout, Bull Trout. Morning hours typically provide optimal glassy conditions for kayak and stand-up paddleboard (SUP) touring.
Warm water temperatures, peak swimming, active watersports, and open full-service campgrounds. Highest weekly attendance; plan early arrivals on summer weekends.
Spring pre-spawn and fall feeding transitions create prime trophy angling conditions. Cooler air, lower boat traffic, and vibrant seasonal shoreline foliage.
Northern cold winter conditions with freezing air temperatures and potential surface ice formation. Ramps and water systems may be winterized. Confirm open status before visiting.
No external source rows are cited by the data currently shown on this page.
Updated
Scores are heuristics, not safety guarantees. LakeRadar scores summarize available conditions and are not a substitute for official warnings, local rules, or on-water judgment.
All telemetry for Saint Mary Lake is synchronized directly from authorized federal and state monitoring networks (USGS, NWS, NOAA, and state environmental authorities). Observations are strictly instrumented readings — unmonitored sensors are transparently disclosed rather than synthetic estimates.
Last source audit: Oct 9, 3:48 AM MDT