Summer in New York City runs roughly June through August, with July and August typically the hottest months. Daytime highs commonly reach the low-to-mid 80s Fahrenheit, with warmer stretches pushing into the upper 80s and occasionally the 90s.
Humidity Makes It Feel Hotter
It’s rarely just the temperature that makes a New York summer day uncomfortable — it’s the humidity riding in on a southerly wind off the Atlantic and the Gulf Stream. When the dew point climbs into the 70s, the air feels heavy and the heat index (the “feels like” temperature) can run well above the actual thermometer reading.
What Counts as a Heat Wave
A heat wave in the New York City area is generally defined as three or more consecutive days with high temperatures at or above 90°F. During these stretches, the National Weather Service may issue heat advisories or excessive heat warnings, particularly when overnight lows also stay unusually warm, since a lack of overnight cooling is one of the biggest health risks in an extended heat event.
The Urban Heat Island Effect
Dense concrete, asphalt, and buildings absorb heat during the day and release it slowly overnight, which is why nights in NYC often stay several degrees warmer than in surrounding suburban or rural areas. Neighborhoods with less tree cover and green space tend to run noticeably hotter than parks and waterfront areas.
Staying Safe in the Heat
Stay hydrated, limit strenuous outdoor activity during the hottest part of the afternoon, and check on elderly neighbors or anyone without reliable air conditioning. The city opens cooling centers during major heat events, and public pools, beaches, and air-conditioned spaces like libraries can offer relief. Never leave children or pets in a parked car, even briefly, as vehicle interiors can reach dangerous temperatures within minutes.
Visit our Summer Heat & Humidity section for heat advisories and cool-down tips throughout the season.