Did it freeze last night?

According to the The Weather Channel it doesn't appear so, but sure enough this morning there was a light glaze of frost on the rooftops.

I found this excerpt from a website called About Frost while Googling the matter:

But the low temperature was only 35°F, How did frost form?

What is important is not what the temperature was at the thermometer but what the temperature was where the frost formed, and if frost formed the local temperature was below freezing.
A thermometer indicates the temperature where the thermometer is, usually a few feet above the ground. Because cold air sinks relative to warmer air and because the ground can cool very quickly the temperature at ground level can be cooler than a few feet higher where the thermometer is, eventhough the thermometer indicates a temperature that is above freezing, it can easily be below freezing a few feet lower. 

So it appears that we had our first frost of the season last night. I really need to a get a ground thermometer and start tracking temperatures in the garden.