What is the stated main idea in the paragraph?

The temperature had been more than 100 degrees for seven days in a row. The city was in the middle of a heat wave. There had been no rain to cool things off. Even at night, the temperature stayed in the 90s. So many people were using air conditioners and fans that the power kept going off.

A.
The temperature had been more than 100 degrees for seven days in a row.

B.
There had been no rain to cool things off.

C.
The city was in the middle of a heat wave.

D.
So many people were using air conditioners and fans that the power kept going off.

C. The city was in the middle of a heat wave.

The main idea in the paragraph is C. The city was in the middle of a heat wave.