Signs of Spring?

I saw a robin this week, some say it is a sign of Spring.

However, I think it was just a tease. The weather is supposed to turn colder and the lows are going to drop into the low twenties. Fearing for our seedlings in the greenhouse, I delivered a burner that attaches to the top of a propane tank to my sister. We are planning to run it for the next few nights.
All of the seedlings look great and she has even transplanted cauliflower and tomatoes to the next size pot. The celery is coming along as well as the eggplant. Hopefully this cold snap will be short lived and the warmer days will return soon.