What is the average temperature in summer in Svalbard?

Summers in Svalbard are extremely cool, but not bitterly cold. Temperatures are actually quite predictable and are typically in the 40's in the day and 30's at night. It rarely makes it into the 50's, though this is occurring more these days (The High Arctic is warming more than anywhere on the globe). I don't believe it has ever reached 60 degrees, at least at Longyearbyen. But it is also relatively immune to incursions of cold air that would bring snow and extended subfreezing temperatures due to being surrounded by water. Even so far north, there simply is not a source of cold air to do this when there are 24 hours of daylight to heat the surface, however weakly.
Otherwise, conditions tend to be cloudy and somewhat windy, with frequent light rain.