Driving at 8am between boulder, co and longmont, co, on October 15th, 2013. The temperature was around 30 degrees, which it had been around for the whole drive, about 45 minutes at that point. I had just come down from about 8000ft elevation to about 5000ft elevation (with a good bit of up and down and some bumpy roads in between), but had been at that elevation on city streets for about 15 minutes. There had been light snow in the mountains, but none once I was on the plains. I had been running my rear defrost off and on (though I didn't notice if it was on or off at the exact time of the incident), as well as heat and front defrost. I was traveling at about 30 mph on a smooth highway when I heard a very loud noise, then saw that my rear window was gone, completely shattered. I had opened the rear window to load the car before leaving.

- Longmont, CO, USA