So what exactly does that mean for 'me!' Lows tonight along and north of I-10 will be below freezing for 11-15 hours. That's long enough to stress pets and livestock so they need extra food and shelter. Tropical plants in particular will take a hard hit if not protected (remember last winters freeze?? I lost many tropicals in my yard!)
Freezing temps will stretch all the way to the coast with lows in the 20's even in coastal counties! Expect temps below freezing for 6-10 hours even in the first tier of counties.
As for exposed water pipes, here's the deal. Low temps really need to reach into the low 20's - upper teens to freeze pipes. HOWEVER... we will be close to that in the north and west counties so take precautions if you are at all worried about bursting pipes. If you have a sprinkler system with an above ground 'relief' air valve I'd think about wrapping that up as well.
Here's a look at overnight lows tonight. We will be just as cold or a bit colder Wednesday night into Thursday morning.