im glad the air conditioner broke on a day where temperature only hit 100 degree.
in my opinion the whole sentence is a verbal irony sentence.
Verbal irony occurs when the literal meaning of what someone says is different from—and often opposite to—what they actually mean. (in a sarcastic way)
Example:
When there's a hurricane raging outside and someone remarks "what lovely weather we're having,"
when its too hot (42°) and you say wow what a lovely weather.
I hope it is helpful! :)
