| Mount Duke | |
| Elevation M: | 2379 |
| Elevation Ref: | [1] |
| Prominence M: | 389 |
| Range: | Joffre Group Lillooet Ranges Coast Mountains |
| Listing: | Mountains of British Columbia |
| Location: | British Columbia, Canada |
| District: | Lillooet Land District |
| Map: | Canada British Columbia#Canada |
| Map Size: | 270 |
| Label Position: | right |
| Coordinates: | 50.3186°N -122.3831°W |
| First Ascent: | 1966 by M. Juri, T. Anderson |
| Easiest Route: | Scramble via northwest ridge |
Mount Duke is a 2379abbr=offNaNabbr=off mountain summit located in the Joffre Group of the Lillooet Ranges, in southwestern British Columbia, Canada. It is situated 300NaN0 east of Pemberton, and 100NaN0 southwest of Duffy Lake. The highest peak in the Joffre Group, Mount Matier, rises 4.40NaN0 to the west. The mountain's name was submitted by Reverend Damasus Payne, a Benedictine monk and mountaineer, to honor Archbishop William Mark Duke. It was officially adopted on April 21, 1966, by the Geographical Names Board of Canada.[2] Precipitation runoff from the peak drains into Caspar Creek and Twin One Creek.
Based on the Köppen climate classification, Mount Duke is located in a subarctic climate zone of western North America.[3] Most weather fronts originate in the Pacific Ocean, and travel east toward the Coast Mountains where they are forced upward by the range (Orographic lift), causing them to drop their moisture in the form of rain or snowfall. As a result, the Coast Mountains experience high precipitation, especially during the winter months in the form of snowfall. Temperatures can drop below −20 °C with wind chill factors below −30 °C. The months July through September offer the most favorable weather for climbing Mount Duke.