June 21 is generally a great time to visit Nantucket. While there is a slight chance of rain (23%), showers are usually brief. Expect comfortable 17°C weather. It's a lively time to explore Nantucket, with most attractions operating at full capacity.
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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 June 21
"Mild & Comfortable. Expect average highs of 17.3°C. 23% chance of rain."
What to Wear in Nantucket in June
Based on historical data for June 21, Nantucket typically experiences temperatures between 15.5°C and 17.3°C. We recommend packing light jacket, long pants to stay comfortable. Trends suggest it will stay mostly dry (23% rain probability), but checking the forecast before heading out is always wise.
Complete Packing Guide
Weekly breakdown & essential items for Nantucket
Smart Suitcase
- Light Jacket
- Long Pants
Average High
17.3°C
Daytime Peak
Average Low
15.5°C
Nighttime Low
Feels Like
17.3°C
🌤️ Feels accurate
Rain Chance
23%
Avg 1.2mm if it rains
Cloud Cover
58%
Overcast
Pressure
1015.8 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
04:00 - 10:00
16:00 - 19:00
Type I-II
🔴 15 min to burn
Type III-IV
🟡 23 min to burn
Type V-VI
🟢 38 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
15.5°C
Pleasant
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
Busy
72/100 pressure index
Health Advisory
Healthy
Routine only • View Details →
Landing Slots
~102
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in Nantucket
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
04:08
☀️ Noon
11:43
🌇 Sunset
19:18
⏱️ Daylight
15h 9m
Wind Speed
26.2 km/h
Moderate wind
Sunshine
11.5 hrs
Direct Sun (Cloud-free)
Humidity
89%
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
🔴 Very 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 June 21 averages 17.3°C with a 23% precipitation probability. Wedding/Outdoor Event Score: 86/100."
— 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
June 23
18°C • 21% rain
Score
88
June 24
18.3°C • 21% rain
Score
88
June 25
18.5°C • 20% rain
Score
88
💡 Moving your event by a few days could significantly improve weather conditions
Compare Other Cities
Same date (June 21) in other destinations
🌍 Explore the same date in different destinations around the world
📍 Is Nantucket Worth Visiting on June 21?
Planning a trip to Nantucket on June 21? 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 17.3°C with a 23% historical precipitation risk.
✈️ Travel Logistics: Approximately 102 landing slots available daily during this period, indicating manageable crowd levels.
📊 Historical Extremes: The hottest June 21 recorded in the last 30 years saw temperatures hit 20.7°C in 2024, while the coldest dropped to 14.2°C in 2023.