Mount Jefferson (Oregon)Mount Jefferson (Oregon) at a Glance
About Mount Jefferson (Oregon)
Mount Jefferson is a 3,199-metre volcanic peak in the Cascade Range of central Oregon, United States. It is one of the state’s tallest mountains and a major landmark of the central Cascades.
Alpine routes and long backcountry trails lead into the mountain’s wilderness, with glaciated high slopes and ridgelines that attract experienced hikers and mountaineers. Scenic views from near the summit include other Cascade volcanoes on clear days.
The mountain is a stratovolcano formed by Cascade volcanic activity and sits within an area designated for wilderness protection to conserve its alpine environment. Recreational use has long focused on non-motorized backcountry travel and mountaineering.
Situated in central Oregon within the Mount Jefferson Wilderness, the peak is northwest of the Cascade crest and is accessed from forested valleys on its flanks.
- Elevation: Summit elevation is about 3,199 metres (10,497 feet), making it one of Oregon’s highest peaks.
- Wilderness area: Located within the Mount Jefferson Wilderness, access is by trail and requires backcountry planning and permits where applicable.
Best Time to Visit Mount Jefferson (Oregon)
Late summer is the typical window for ascent when weather is least severe.
Weather & Climate near Mount Jefferson (Oregon)
Mount Jefferson (Oregon)'s climate is classified as Tundra - Tundra climate with cold summers (peaking in August) and freezing winters (coldest in March). Temperatures range from -10°C to 14°C. Heavy rainfall (2315 mm/year), wettest in December.
| Month | Comfort | Temp | Feels | Rain | Sky | Humidity | Wind | UV | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | - | -8° - -1° | -11° | 349 mm | - | - | 5.0 m/s | - | - |
| February | - | -9° - -1° | -11° | 271 mm | - | - | 4.6 m/s | - | - |
| March | - | -10° - -3° | -12° | 240 mm | - | - | 4.4 m/s | - | - |
| April | - | -10° - -1° | -11° | 163 mm | - | - | 4.2 m/s | - | - |
| May | - | -7° - 2° | -7° | 121 mm | - | - | 4.2 m/s | - | - |
| June | - | -4° - 6° | -3° | 98 mm | - | - | 4.2 m/s | - | - |
| July | - | 0° - 12° | 3° | 42 mm | - | - | 4.2 m/s | - | - |
| August | - | 1° - 14° | 5° | 56 mm | - | - | 4.1 m/s | - | - |
| September | - | 0° - 11° | 2° | 95 mm | - | - | 4.2 m/s | - | - |
| October | - | -3° - 7° | -2° | 170 mm | - | - | 4.5 m/s | - | - |
| November | - | -7° - 1° | -9° | 337 mm | - | - | 4.9 m/s | - | - |
| December | - | -9° - -1° | -11° | 373 mm | - | - | 5.0 m/s | - | - |
How to Get to Mount Jefferson (Oregon)
Mount Jefferson is approached via the Willamette and Deschutes National Forests. Common starting points include park-and-hike trailheads along US‑20 and forest roads; access requires a vehicle and possibly unpaved roads. Check the U.S. Forest Service (Willamette NF / Deschutes NF) for trail conditions and permits.
Tips for Visiting Mount Jefferson (Oregon)
- This is a high‑altitude, glaciated peak-only experienced mountaineers should attempt technical routes; hire guides with alpine experience.
- Approach with sufficient acclimatization-trips commonly base from North and South Breitenbush areas.
- Check with the U.S. Forest Service or local ranger district for current trail and climbing conditions; volcanic activity and weather can change access.