locales = locations (places) lows in the teens = low temperatures will be 13-19*

These are degrees Fahrenheit. So the temperature will change from 26.7 C today to somewhere between -7.2C and -10.6 C on Tuesday. This is particularly dramatic but extreme temperature fluctuations are a characteristic of continental climates. "Lows" means the lowest temperature of the day.

Lows in the teens refers to the minimum temperature ranging from 10 to 19 degrees. And locales refers to the different places. I hope this helps. If you'd like, you can feel free to look at my teaching profile and class offerings, and message me if you think I can help you practice your English.