When did you move to NYC? It hasn't gotten hot yet this year but you'll see that living without an AC or a fan is hell here. The inside of apartments (especially older ones which most are) gets amazingly hot and it stays that way once it heats up outside.
It has been a rather cool spring and we haven't had a heat wave yet but rest assured once we do you will find inside your apartment will be unbearably hot and humid. And it will stay that way well into autumn.
The city itself gets hot too with a lack of airflow and tons of AC units pushing out heat and exhaust from vehicles and the Subway as well. The Subway stations will be unbearably hot as well since the train is air conditioned and has lots of heat exhaust from this and its regular operation.
Luckily apartments are small enough that a decent window AC can usually keep an entire unit comfortable and only has to be run when you're home.
It has been quite cool so far this year. My experience moving to NYC from northern CA three years ago has been: 1st summer (2014) I got by without an AC (but with fans) and it wasn't that bad. 2nd summer (2015) was quite agonizingly hot and humid and I vowed to get an AC for the next year. 3rd summer (2016) I had an AC and was very glad as it was quite hot that year as well.
It has been a rather cool spring and we haven't had a heat wave yet but rest assured once we do you will find inside your apartment will be unbearably hot and humid. And it will stay that way well into autumn.
The city itself gets hot too with a lack of airflow and tons of AC units pushing out heat and exhaust from vehicles and the Subway as well. The Subway stations will be unbearably hot as well since the train is air conditioned and has lots of heat exhaust from this and its regular operation.
Luckily apartments are small enough that a decent window AC can usually keep an entire unit comfortable and only has to be run when you're home.