Mountain Peak

South Sister Volcano peak

Cascade Range, Oregon 10,358 ft
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Range
Cascade Range
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South Sister Volcano rises to 10,358 ft in Pacific-Ranges within the Cascade Range range.

Standing tall at an elevation of 10,358 feet (3,157 meters), it is the third highest summit in Oregon. As part of the larger Three Sisters Volcanic Complex, South Sister is a stratovolcano that formed as a result of successive volcanic eruptions over thousands of years.

During the winter season, South Sister Volcano receives heavy snowfall due to its high elevation. The snowpack range can vary depending on the year and weather conditions, typically ranging from 10 to 20 feet (3 to 6 meters). This makes it a popular destination for winter mountaineering and backcountry skiing enthusiasts.

The mountain's runoff feeds into several creeks and rivers in the region, including the Deschutes River and the upper reaches of the Middle Fork Willamette River. These water sources contribute to the local ecosystem and provide vital resources for the surrounding communities.

The name "South Sister" refers to its location in relation to the nearby peaks of Middle Sister and North Sister. The Native American names for these mountains translate to "Faith", "Hope", and "Charity" respectively, reflecting their significance in local folklore. Many legends and stories surround South Sister, including tales of ancient volcanic activity and spiritual connections to the land. Its prominent profile and breathtaking beauty continue to inspire awe and admiration, attracting adventurers and nature enthusiasts from far and wide.

For trail conditions and access, search Wikipedia or the local land manager's site. Browse other peaks in the Pacific-Ranges range.

StateOREGON
RangeCascade Range
Elevation10,358 ft
Latitude44.1035°
Longitude-121.7693°
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Regional snowpack

Snowpack near South Sister Volcano

Snow water equivalent and snowpack depth at SNOTEL stations near the peak. Best proxy for what's currently sitting on the summit.

Regional streamflow

Streamflow near South Sister Volcano

USGS streamgauges in the basin drained by this peak. Spring snowmelt from the summit feeds these flows.

Detailed forecast

Plan around incoming weather

Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column -- snow at this elevation typically lags the radar signature by a few hours.

Hourly detail

Next 5 days, hour by hour

Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.

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Deep dive

5-day forecast table

Every 3 hours, broken out across temperature, snow, rain, humidity, and wind.

TimeConditionTemp (°F)Snow (in)Rain (in)Humidity (%)Wind (mps)Wind dir
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Long-term outlook

15-day forecast

Daily temperatures, snow, and rain projected over the next two weeks.

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Get South Sister Volcano on your phone.

Save this peak as a favorite and get push alerts when storms move in, fresh snow falls upstream, or NWS issues a weather warning. Free, account optional.

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QR code -- scan with your iPhone to install Snoflo

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Snoflo Premium

Favorites and custom weather alerts are part of Snoflo Premium. Save peaks, set snowfall or wind thresholds, and get push alerts when conditions cross.

Set up an alert

Custom alerts are configured in the Snoflo iOS app. Open the app, navigate to this peak, and tap the bell icon to set thresholds for snowfall, temperature, or wind.

{# FAVORITE-LIMIT MODAL — fires when a non-premium user hits the 3-favorite cap. Mirrors the iOS PremiumGateSheet's .bookmarkLimit case: same copy direction (limit reached → unlimited with Premium), same primary CTA shape. Triggered from toggle_fave (pre-flight) and the 403 error handler. #} {# ALERTS-IN-APP MODAL — opened from the Account dropdown's "Alerts" link. Push-notification alerts (snow / flow / buoy / ski) are managed in the iOS app because they require APNs + device tokens; the webapp has no equivalent surface, so the right thing to do is point users at the App Store. Mirrors the per-gauge #sf-cp-alerts-modal popup on recChildFlow.html. #}