Minus and plus a specific temperature degree (weather)

Question

When we are going to say the weather temperature is below 0 degrees we use X degrees below zero or minus X degrees, but what about the contrary case?

For instance we would probably say something like:

• It's 3 degrees below zero centigrade today.
• It's minus 3 degrees today.

I know we would use the structure: X degrees above zero, but the question is that whether we can use the similar case as is in "minus" case and use the construction like:

• The tempreraure is plus i.e. 30 degrees C

When I search on the internet I don't encounter any sort of similar structure and it appears to me as if in "above zero" case, we can omit the adjective plus by default, because anybody knows that not mentioning below or above would mean it is plus as a default!

Do you confirm my take over this matter?

Answer 1

Without further context "It will be two degrees today" could mean "+2 degrees Celcius" or "+2 degrees Fahrenheit". You don't need to say "plus" or "above zero".

There is nothing wrong with adding a clarifying term, especially if you are comparing with below zero temperatures:

After three nights of frost, temperatures will rise and be above zero on Wednesday."

The temperature will be minus 4 in the countryside, but plus 2 in the city.

But if there is no comparison, you don't use "plus"

Temperatures will be cool: 8 in Glasgow, 10 in Cardiff and 13 in London.

The words "plus" and "minus" should be used to qualify numbers, and you should use "positive" or "negative" as general adjectives. You should say "a negative number". But this point is often not observed by native speakers, and "a minus number" is quite commonly heard.