Compact Fluorescent Bulbs

I noticed something interesting last night as I was on the front porch trying to figure out why the Christmas lights kept causing the GFCI breaker on the outlet to keep tripping... When compact fluorescent light bulbs are very cold (say about freezing or below--it was about 27 degrees out there last night) they are dim. Now that might not be very exciting to you, and frankly I'm not really ecstatic about it, but I just thought it was interesting. They warm themselves up after a minute or so, and in doing so they brighten up as well, so they're still useful. But if you ever need instant bright light from a fluorescent bulb on a cold night, you'll be out of luck. [I'm still not 100% certain why the GFCI breaker kept tripping, but I narrowed it down to one path of cords and lights.]