In this case, the Spanish verb hacer refers to weather conditions or atmospheric temperature.
In this way the verb hacer in its many conjugations works as an impersonal verb, that is, it is conjugated in the third person in singular, without any reference to the subject.
This means it is not necesary the subject in a sentence with these conditions.
According to this rule, the correct option is hace frío.
Therefore the complete sentence is:
In my city during the autumn it is cold
