As you can see, the low this morning was 3 degrees F.  By the time I took this image (10:25) the outdoor temperature had risen to 11 degrees and the indoor temperature to 55 degrees in the room where this thermometer was located.  The thermometer was in the sunroom which we had closed off yesterday.  It still gets heat, but not enough.  I’m wondering how low it got in that room last night.  The furnace had been turned up at least four hours before I took this image so it had to have been much lower.  You can see from the little arrows that both the outside and inside temperatures were rising.