The official low for Tucson is forecast to be 24°F (-4.5°C) tonight. That means down here in the very level Rillito flats we'll be around 18°F (-7.75°C). So guess what I have to do.
Put the hummingbird feeders back out at least a half hour before sunrise. Our forecast high for tomorrow is only 43°F (6°C), about 20 below normal. We haven't had it this cold here since early Feburary, 2011, when it was about 5 degrees colder. Wish my garden the best. I have the Shroud of Turnip in place.