September 11 is statistically one of the best days of the year in Portland. With minimal rain risk (10%) and pleasant highs of 26°C, it's ideal for outdoor adventures. Portland is currently in its most popular travel window, meaning vibrant crowds and premium pricing.
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Essential Travel Info for Portland
Currency
USD
$ United States dollar
Language
English
Driving
Right side
Safety
Moderate Safety
GPI: 2.44
Portland Weather Forecast for September 11
"Warm & Sunny. Expect average highs of 25.8°C. 10% chance of rain."
What to Wear in Portland in September
Based on historical data for September 11, Portland typically experiences temperatures between 13.6°C and 25.8°C. We recommend packing t-shirt, light clothing, layers (onion system) to stay comfortable. Trends suggest it will stay mostly dry (10% rain probability), but checking the forecast before heading out is always wise.
Complete Packing Guide
Weekly breakdown & essential items for Portland
Smart Suitcase
- T-Shirt
- Light Clothing
- Layers (Onion System)
Average High
25.8°C
Daytime Peak
Average Low
13.6°C
Nighttime Low
Feels Like
26.4°C
☀️ Feels accurate
Rain Chance
10%
Avg 0.3mm if it rains
Cloud Cover
39%
Overcast
Pressure
1015.4 hPa
Low volatility
Portland Weather Conditions & UV Index
Weather Confidence
30-year variance analysis
Based on 10 years of data
🎯 This date historically delivers consistent weather 80% of the time. Safe to plan outdoor activities with confidence.
Sun Exposure
UV Index & Safety Guide
Protection Needed
SPF 30 recommended
05:00 - 10:00
16:00 - 18:00
Type I-II
🔴 26 min to burn
Type III-IV
🟡 39 min to burn
Type V-VI
🟢 65 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
18.2°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
High
94/100 pressure index
Health Advisory
Healthy
Routine only • View Details →
Landing Slots
~305
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in Portland
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
05:45
☀️ Noon
12:08
🌇 Sunset
18:31
⏱️ Daylight
12h 46m
Wind Speed
11.2 km/h
Light breeze
Sunshine
10.4 hrs
Direct Sun (Cloud-free)
Humidity
63%
Slightly humid
Travel Intelligence
Exclusive flight analytics & health data for Portland
Smart Flight Estimator
Airport-to-Airport Logistics
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Travel Health & Safety in Portland
Travel Comfort Index
Real-time tourism conditions
Weather Quality
☀️ Excellent
Tourist Crowds
🟡 Busy
Price Level
💰💰💰 Expensive
Health & Wellbeing
Meteo-Health Forecast
Stable conditions. Low risk of headaches.
Weather unlikely to affect joint pain.
Moderate fish activity expected.
Air quality is acceptable. Sensitive individuals should limit prolonged outdoor exertion.
Regional Safety Profile
Seismic Activity
Rare minor tremors. Buildings are earthquake-resistant.
Volcanic Activity
Nearest: Mount St. Helens
84km away
"According to 30YearWeather's analysis of 30 years of NASA satellite data, Portland on September 11 averages 25.8°C with a 10% precipitation probability. Wedding/Outdoor Event Score: 100/100."
— Source: 30YearWeather.com|Data: NASA POWER (1991-2021)|View Methodology
Portland Weather History (2010–2024)
Temperature History
Hall of Fame
Records from last 10 years
Compare Other Cities
Same date (September 11) in other destinations
🌍 Explore the same date in different destinations around the world
📍 Is Portland Worth Visiting on September 11?
Planning a trip to Portland on September 11? Our historical weather analysis based on 30 years of NASA satellite data shows that this time of year typically offers vibrant summer conditions averaging 25.8°C with a 10% historical precipitation risk.
✈️ Travel Logistics: Approximately 305 landing slots available daily during this period, indicating manageable crowd levels.
📊 Historical Extremes: The hottest September 11 recorded in the last 30 years saw temperatures hit 32.2°C in 2022, while the coldest dropped to 11.1°C in 2020.