As I write this, the National Weather Service--who has been abysmal this year in short term predicting the weather here--is projecting 39F low cloudless tomorrow morning at the airport. Who knows what they will predict in 4 hours?
We have had a heck of a rain and cloud cover the past day. If the cloud cover prevents the sun from heating us up today, and if the sky clears out of cloud cover and stay cleared all or most of the evening long tonight it may indeed get very cold tomorrow morning. They are predicting winds out of the NNW tonight. Again, if accurate that can drop the temp significantly.
Bottom line if you are in an outlying part of Maricopa Co. or in a cold accumulating section in town you may have frost on the ground tomorrow morning. I would recommend covering sensitive evergreens.
https://extension.arizona.edu/sites/extension.arizona.edu/files/pub... - geared to commercial growers but applicable information for home owner
https://www.unce.unr.edu/publications/files/ho/2007/sp0718.pdf - great photos of freeze damage
49F at the airport at 9PM. I think the NWS might be right about 35F out there at 7AM tomorrow. Getting cold just thinking about it.
Just got this link in my email and thought it very worthy:
FREEZE WARNINGS and 3 Levels of Frost Protection for Your Plants
32.2F yesterday. 29.7F, first time below freezing this morning while airport reporting 37F. Banana cussed me on the way past it to read the thermometer.
Tomorrow morning will be cold. Then the NWS are promising some warmth at just above freezing; not that they have been reliable.