Sun speed is a function of the time of year. the sun will have an exact speed today, will be slightly slower tomorrow as the sun moves north a tiny bit. You could pick any day from a date picker and get the speed of the sun for that day.
No, as from the distance to the north pole. The sun travels between the tropics of cancer and Capricorn. The tropic of cancer is a much smaller circle on a flat earth than the tropic of Capricorn, yet it still completes a circle in 24 hours. In other words, it speeds up as the sun travels south. We know the equator is 6,374 km. We know the equator is 10,007km from the north pole, and that the tropics are 23°26′13.9 degrees either side. So with a bit of maths, we can worth out the exact speed on any day. It is close to 1000mph on during the equinox for example.