[azernik]

Probably very similar to the temperatures anywhere else on Mercury's surface - with no atmosphere, temperature doesn't vary much with altitude. So, somewhere around 500-700K during the (3-4-month-long) daytime, and around 100K at night.

[egfx]

"Because the crater is deep, and the Sun never gets very high off the horizon at the pole, there are parts of the crater floor that are permanently in shadow; they literally are never illuminated by the Sun. Those spots can be very cold; well below the freezing point of water" from this article http://www.slate.com/blogs/bad_astronomy/2012/11/29/_mercury...

[azernik]

That's only for polar craters, which this is not. The poles are in any case quite cold by Earth standards.

[egfx]

801° fahrenheit