September in New York is a total mood swing. One day you’re sweating through a linen shirt on a packed L train, and the next you’re shivering in a drafty rooftop bar wishing you’d brought that denim jacket. Honestly, it's the best time to be here, but if you don't play your cards right with the weather in nyc for september, the city will chew you up and spit you out—mostly in the form of a $20 "emergency" umbrella purchase.
New York doesn't do "gentle" transitions. It's a tug-of-war. The ghost of August humidity is still fighting the first crisp whispers of fall, and neither side wants to give up ground.
The Reality of September Temperatures
Basically, early September is just Summer 2.0. You’ll see averages around 75°F to 80°F (24°C–27°C) at the start of the month, but don’t let that "average" fool you. Heat waves still happen. In 2015, Central Park hit a staggering 97°F in early September. That’s rare, sure, but it's a reminder that the sun still has teeth.
By the time you hit late September, things get way more comfortable.
Daily highs slide down to about 70°F (21°C). The nights? They drop into the high 50s (around 14°C–15°C). It’s that perfect "walk for five miles and not need a shower" weather. The air gets thinner, the light gets golden, and the oppressive "trash smell" that defines NYC in August finally starts to fade.
According to the National Weather Service data from Central Park, the temperature drop throughout the month is about 9 degrees on average. It's a steady descent into sweater weather, but it’s rarely a straight line. You have to be ready for 85 degrees on a Tuesday and 62 on a Wednesday.
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Humidity and the Hurricane Factor
People forget that September is the absolute peak of the Atlantic hurricane season.
We aren't just talking about a light drizzle. When a tropical system or its remnants decide to take a detour up the East Coast, the city gets drenched. Historically, some of the most intense rain events have happened right now. Tropical Storm Floyd in 1999 dumped up to 15 inches of rain in parts of the region. Even if we don’t get a direct hit, the humidity can spike.
Relative humidity usually hovers around 72%. That sounds high, but because the air is cooler than in July, it doesn’t feel like you’re walking through a warm soup. It’s mostly breezy and pleasant.
Cloud cover is pretty consistent too.
The sky is overcast or mostly cloudy about 37% of the time. Interestingly, September 23 is statistically one of the clearest days of the year in the city. If you’re planning a trip to the Top of the Rock or the Edge, that’s your golden window for visibility.
Rainfall by the Numbers
- Average Days of Rain: 8 days.
- Total Rainfall: Roughly 3.5 to 3.7 inches.
- Daylight: We lose about an hour and 17 minutes of sun from the 1st to the 30th.
What to Wear (and What to Leave at Home)
You’ve got to dress in layers. There is no other way.
If you leave your hotel in a heavy sweater at 8:00 AM, you will be miserable by noon. If you go out in just a tank top, you’ll be freezing the second the sun ducks behind a skyscraper. The "NYC Uniform" for September is essentially a high-quality t-shirt paired with a light jacket or a "shacket."
Think cotton, denim, and light knits.
Footwear is the most critical decision you'll make. September is a prime walking month. Those leather boots you just bought? Save them for October. Your feet will swell in the heat, and if it rains, suede is a death sentence. Stick to breathable sneakers or broken-in loafers.
And please, leave the flip-flops for the beach. New York City sidewalks are not a place for exposed toes, especially when a sudden September downpour turns the street corners into literal rivers.
Why September is Actually the Best (Despite the Chaos)
The light in the city changes in September. It’s a phenomenon photographers obsess over. Because the sun is lower in the sky, the "Manhattanhenge" vibes linger, and the shadows against the brownstones get longer and more dramatic.
You get about 12.5 hours of daylight. That’s plenty of time to hit Central Park, walk the High Line, and still have a late dinner outside.
Speaking of outdoor dining, this is the "Goldilocks" zone. It’s not so hot that you’re sticking to the chair, and it’s not so cold that the heat lamps are blasting your face. It's just right.
Expert Tips for Navigating the Month
- Check the "RealFeel": The thermometer might say 72, but if the humidity is up and the sun is out, it feels like 80.
- The Subway Factor: The stations are still underground saunas. Even if it’s 60 degrees outside, the platforms will be 85. Wear a base layer that looks good on its own.
- Waterproof Everything: Don't trust a "0% chance of rain" forecast. Coastal weather changes in minutes. A packable rain shell is worth its weight in gold.
- Sunscreen is still a thing: The UV index stays around 6 in early September. You can still get a nasty burn while sitting in Sheep Meadow.
The weather in nyc for september is a fickle beast, but it’s the most rewarding time to experience the five boroughs. You get the energy of the "back to school" season mixed with the tail end of summer’s freedom.
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To make the most of your time, focus on the transition. Pack for two seasons at once. Keep an eye on the tropics via the National Hurricane Center if you're traveling from afar. Most importantly, embrace the unpredictability. Whether you're caught in a sudden deluge in Times Square or basking in a perfect 70-degree afternoon in Brooklyn Bridge Park, that's just the New York experience.
Pack a light trench coat. Wear your best walking shoes. Watch the forecast, but don't let it dictate your life—the city is beautiful even when it's gray.