September 15 is generally a great time to visit Nantucket. While there is a slight chance of rain (21%), showers are usually brief. Expect comfortable 19°C weather. Moderate travel demand makes this an excellent time for a balanced Nantucket experience.
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Essential Travel Info for Nantucket
Currency
USD
$ United States dollar
Language
English
Driving
Right side
Safety
Moderate Safety
GPI: 2.44
Nantucket Weather Forecast for September 15
"Mild & Comfortable. Expect average highs of 19.4°C. 21% chance of rain."
What to Wear in Nantucket in September
Based on historical data for September 15, Nantucket typically experiences temperatures between 17.5°C and 19.4°C. We recommend packing t-shirt, light clothing to stay comfortable. Trends suggest it will stay mostly dry (21% rain probability), but checking the forecast before heading out is always wise.
Complete Packing Guide
Weekly breakdown & essential items for Nantucket
Smart Suitcase
- T-Shirt
- Light Clothing
Average High
19.4°C
Daytime Peak
Average Low
17.5°C
Nighttime Low
Feels Like
19.4°C
🌤️ Feels accurate
Rain Chance
21%
Avg 1.4mm if it rains
Cloud Cover
49%
Overcast
Pressure
1018.8 hPa
Medium volatility
Nantucket Weather Conditions & UV Index
Weather Confidence
30-year variance analysis
Based on 10 years of data
🎯 This date historically delivers consistent weather 100% of the time. Safe to plan outdoor activities with confidence.
Sun Exposure
UV Index & Safety Guide
Protection Needed
SPF 30 recommended
05:00 - 09:30
16:00 - 17:00
Type I-II
🔴 27 min to burn
Type III-IV
🟡 41 min to burn
Type V-VI
🟢 68 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
16.2°C
Noticeable
Heat Stress
Low
No heat warning
🙂 Best outdoor time:
Any time during daylight hours
Travel & Logistics Insights
Local Calendar
Business Day
Standard hours in United States
Flight Traffic
Moderate
52/100 pressure index
Health Advisory
Healthy
Routine only • View Details →
Landing Slots
~74
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in Nantucket
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
05:22
☀️ Noon
11:37
🌇 Sunset
17:52
⏱️ Daylight
12h 30m
Wind Speed
27.9 km/h
Moderate wind
Sunshine
9.6 hrs
Direct Sun (Cloud-free)
Humidity
82%
Humid / Damp
Travel Intelligence
Exclusive flight analytics & health data for Nantucket
Smart Flight Estimator
Airport-to-Airport Logistics
unlock smart flight estimates
Add your home location in settings to see airport details.
Travel Health & Safety in Nantucket
Travel Comfort Index
Real-time tourism conditions
Weather Quality
☀️ Excellent
Tourist Crowds
🟡 Busy
Price Level
💰💰💰 Expensive
Health & Wellbeing
Meteo-Health Forecast
Moderate fluctuations. Some sensitivity possible.
Weather unlikely to affect joint pain.
Moderate fish activity expected.
Air quality is excellent. Perfect for outdoor activities.
Regional Safety Profile
Seismic Activity
Zero seismic activity detected in 30 years.
Atlantic Hurricane Risk
Season: Jun - Nov
"According to 30YearWeather's analysis of 30 years of NASA satellite data, Nantucket on September 15 averages 19.4°C with a 21% precipitation probability. Wedding/Outdoor Event Score: 89/100."
— Source: 30YearWeather.com|Data: NASA POWER (1991-2021)|View Methodology
Nantucket Weather History (2010–2024)
Temperature History
Hall of Fame
Records from last 10 years
Better Alternatives Nearby
Consider these dates within ±7 days
September 9
20.2°C • 14% rain
Score
95
September 8
20.2°C • 16% rain
Score
91
September 10
20.1°C • 15% rain
Score
90
💡 Moving your event by a few days could significantly improve weather conditions
Compare Other Cities
Same date (September 15) in other destinations
🌍 Explore the same date in different destinations around the world
📍 Is Nantucket Worth Visiting on September 15?
Planning a trip to Nantucket on September 15? Our historical weather analysis based on 30 years of NASA satellite data shows that this time of year is characterized by pleasant mild weather averaging 19.4°C with a 21% historical precipitation risk.
✈️ Travel Logistics: Approximately 74 landing slots available daily during this period, indicating manageable crowd levels.
📊 Historical Extremes: The hottest September 15 recorded in the last 30 years saw temperatures hit 22.8°C in 2021, while the coldest dropped to 15.6°C in 2020.