That's an interesting question. Speed climbing[0] is for 100% vertical climbs and seem to attain speeds of 6,000+ft/hr rate of ascent for only a minute. Over 30 minutes, people are very close to climbing a kilometer in vertical height[1]. One of the fastest times that author found was 0.568m/s (6708.6614 ft/hr), with an elevation of 16.4 degrees.

I'm going to assume it's roughly similar for 60 minutes, as well as 30 minutes.

[0] https://en.wikipedia.org/wiki/Speed_climbing [1] http://www.irunfar.com/2012/04/the-30-minute-kilometer-a-loo...