March 18 is generally a great time to visit Portland. While there is a slight chance of rain (39%), showers are usually brief. Expect comfortable 13°C weather. Portland is seeing high visitor numbers, so iconic spots may be busier than usual.
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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 March 18
"Mild & Comfortable. Expect average highs of 12.8°C. 39% chance of rain."
What to Wear in Portland in March
Based on historical data for March 18, Portland typically experiences temperatures between 3.5°C and 12.8°C. We recommend packing heavy coat, scarf, gloves along with other layers to stay comfortable. With a 39% chance of rain, keeping a raincoat or umbrella handy is a smart move.
Complete Packing Guide
Weekly breakdown & essential items for Portland
Smart Suitcase
- Heavy Coat
- Scarf
- Gloves
- Umbrella
Average High
12.8°C
Daytime Peak
Average Low
3.5°C
Nighttime Low
Feels Like
12.2°C
🌤️ Feels accurate
Rain Chance
39%
Avg 3mm if it rains
Cloud Cover
72%
Overcast
Pressure
1017.7 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 89% 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
🔴 38 min to burn
Type III-IV
🟡 57 min to burn
Type V-VI
🟢 95 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
9.1°C
Dry air
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
69/100 pressure index
Health Advisory
Healthy
Routine only • View Details →
Landing Slots
~225
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in Portland
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
06:18
☀️ Noon
12:20
🌇 Sunset
18:21
⏱️ Daylight
12h 2m
Wind Speed
13.7 km/h
Gentle breeze
Sunshine
7.5 hrs
Direct Sun (Cloud-free)
Humidity
78%
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
🟢 Moderate
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 March 18 averages 12.8°C with a 39% precipitation probability. Wedding/Outdoor Event Score: 70/100."
— 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 (March 18) in other destinations
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📍 Is Portland Worth Visiting on March 18?
Planning a trip to Portland on March 18? Our historical weather analysis based on 30 years of NASA satellite data shows that this time of year offers a bracing seasonal atmosphere averaging 12.8°C with a 39% historical precipitation risk.
✈️ Travel Logistics: Approximately 225 landing slots available daily during this period, indicating manageable crowd levels.
📊 Historical Extremes: The hottest March 18 recorded in the last 30 years saw temperatures hit 21.1°C in 2024, while the coldest dropped to 1.1°C in 2025.