Inuvik, of course, was our starting place:

Here are readings for Rock River, which was about 200 miles into the journey. When we got there it was a pleasant day, but a week earlier it had been 32 F with a 50 MPH wind...



Here is Dawson, the bottom of the Dempster Highway:
Weather Underground has a wonderful new Google Map of Personal Weather Stations, so you can see the temps in the whole region.

The Wundergound site has excellent historical information, so I was able to look at the highs and lows for the week of June 9 for several years back. The lowest reading I saw for that week was 29 degrees F, and no precip of any kind.