The ascent of Kala Patthar begins at
Gorakshep (), the original base camp for Mt. Everest. After a brief dip to an ancient lake bed (which now contains a small lake and a helipad), the ascent makes its way up a series of steep switchbacks before levelling off somewhat as it traverses to the eastern side of the mountain. The trail then becomes steep once again until it reaches the wind-swept summit ridge. From there, a five to ten minute
scramble over boulders takes one to the top, which is marked with
prayer flags. There is also a geocaching trackable named Kala Pattar near the summit. Its trackable code is GCG58G. The full ascent usually takes between 1.5 and 2 hours. If the attempt is made starting from
Lobuche, an additional two to three hours (one way) is required. viewed from Kala Patthar The elevation is commonly listed as . One source lists the height as 5,600 meters/18,373 feet. Portland State University Assistant Professor Dr. Luis A. Ruedas took a Garmin eMap GPS unit to the summit on 6 December 2006. These units can average a series of individual satellite readings, making them more accurate than single-reading machines. Averaging 48 readings at 0625h Nepal local time, temperature −20 °C, the GPS recorded the location of the summit as 27°59.750'N, 86°49.705'E (datum: WGS84), and elevation as . Even accounting for the fact that the summit may have approximately one meter of stones added as a celebratory cairn, this is a significant discrepancy with previously recorded elevations. The same unit was consistent concerning previously recorded elevations for Gorak Shep and Everest Base Camp. In October 2008, a GPS with WAAS recorded the summit at 27°59.751'N, 86°49.705'E (datum: WGS84) with an elevation of , confirming the 2006 data. It is possible that since Kala Patthar is merely a minor summit on a ridge leading to
Pumori, different people may have measured different summits. There is a minor summit along this ridge near 27°59.51'N, 86°49.62'E with an elevation of approximately . The summit traditionally referred to as Kala Patthar is, however, completely festooned with prayer flags, making it quite readily recognizable. It is that summit that was recorded as . It is quite clear that the point trekkers climb to is a local maxima on the Pumori ridge, not the summit of Kala Patthar proper. This point is clearly higher than the summit of Kala Patthar, but the name has remained in popular use. ==Climate change==