October 21 is generally a great time to visit Portland. While there is a slight chance of rain (34%), showers are usually brief. Expect comfortable 17°C weather. 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 October 21
"Mild & Comfortable. Expect average highs of 16.5°C. 34% chance of rain."
What to Wear in Portland in October
Based on historical data for October 21, Portland typically experiences temperatures between 7.9°C and 16.5°C. We recommend packing light jacket, long pants, umbrella to stay comfortable. With a 34% chance of rain, keeping a raincoat or umbrella handy is a smart move.
Complete Packing Guide
Weekly breakdown & essential items for Portland
Smart Suitcase
- Light Jacket
- Long Pants
- Umbrella
Average High
16.5°C
Daytime Peak
Average Low
7.9°C
Nighttime Low
Feels Like
16.5°C
🌤️ Feels accurate
Rain Chance
34%
Avg 2.6mm if it rains
Cloud Cover
64%
Overcast
Pressure
1017.8 hPa
Medium volatility
Portland Weather Conditions & UV Index
Weather Confidence
30-year variance analysis
Based on 10 years of data
🎯 This date historically delivers consistent weather 94% of the time. Safe to plan outdoor activities with confidence.
Sun Exposure
UV Index & Safety Guide
Protection Needed
SPF 15 for extended outdoor time
Type I-II
🔴 67 min to burn
Type III-IV
🟡 101 min to burn
Type V-VI
🟢 168 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
13.6°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
High
84/100 pressure index
Health Advisory
Healthy
Routine only • View Details →
Landing Slots
~275
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in Portland
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
06:36
☀️ Noon
11:56
🌇 Sunset
17:16
⏱️ Daylight
10h 40m
Wind Speed
11.2 km/h
Light breeze
Sunshine
6.5 hrs
Direct Sun (Cloud-free)
Humidity
83%
Humid / Damp
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
⛅ Good
Tourist Crowds
🟡 Busy
Price Level
💰💰 Moderate
Health & Wellbeing
Meteo-Health Forecast
Moderate fluctuations. Some sensitivity possible.
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 October 21 averages 16.5°C with a 34% precipitation probability. Wedding/Outdoor Event Score: 82/100."
— 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
Better Alternatives Nearby
Consider these dates within ±7 days
October 14
17.8°C • 27% rain
Score
89
October 15
17.8°C • 28% rain
Score
89
October 16
17.6°C • 29% rain
Score
88
💡 Moving your event by a few days could significantly improve weather conditions
Compare Other Cities
Same date (October 21) in other destinations
🌍 Explore the same date in different destinations around the world
📍 Is Portland Worth Visiting on October 21?
Planning a trip to Portland on October 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 16.5°C with a 34% historical precipitation risk.
✈️ Travel Logistics: Approximately 275 landing slots available daily during this period, indicating manageable crowd levels.
📊 Historical Extremes: The hottest October 21 recorded in the last 30 years saw temperatures hit 20.1°C in 2021, while the coldest dropped to 5°C in 2020.