Temperatures were forecast (at one point) to be in the teens overnight this week. They have since been revised upwards a bit, but I got my greenhouse heater in place. In this case I am using a string of 100 red, green and white incandescent christmas tree lights. The lights should add a few degrees of warmth inside the dome. Everything seems to be growing pretty well in there, but it was too dark for pictures without a tripod. I took this one with an 8 second exposure zoomed in from my picnic table on the patio.