weather forecast (phrase 'upper teens')

[Kwfine]

I was watching weather forecast on TV, but quite don't understand some of the words the reporter said, for example:"...LOWS IN THE UPPER TEENS..."
I must say that I don't know what "upper teens" means exactly?

Could you help clarify please?
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各位前輩安安, 我是kitty喔!

[Jamie (K)]

It means that the low temperature will vary between 15 and 19 degrees.

That's a nice spring day in Celsius, but it's bitter cold in Fahrenheit.

[Kwfine]

[Kwfine]

[Terrestr1al]

The word "teens" is used to describe the numbers between 13-19, or more loosely 10-20.
This is so because the ending of the words end with 'teen', for instance: thirteen.

So "upper teens" is described as being in between 15 and 19 degrees, as Jamie has stated.