Today | Weather | Wednesday, March 18, 2026

Weather in Portland, Oregon

07:58 AM
Now
Cloudy Weather
48° F
Feels Like 48°
Precipitation 4 %
Wind 6 mph
UV Index (0 - 11+) 0
Humidity 88 %
Today
Cloudy Weather
Day 68°
Night 50°
Precipitation 17 %
Wind 8 mph
UV Index (0 - 11+) 2

Portland Weather Forecast Updated

Last updated on
Weather Forecast History
Last Year's Weather on This Day (March 18, 2025)
Rainy Weather

Day

52°

Night

41°

Wind

6 mph

UV Index

2

Precipitation

96 %

Air Quality in Portland

NOW
14 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 2.29 µg/m³
PM10 3.64 µg/m³
O3 0.015 ppm
NO2 1.9 ppb
SO2 0 ppb
CO 0.12 ppm
NH3 0.35 µg/m³
NO 0.04 µg/m³
PM2.5 – Fine particles <2.5μm
PM10 – Inhalable particles <10μm
O3 – Ozone
NO2 – Nitrogen dioxide
SO2 – Sulfur dioxide
CO – Carbon monoxide
NH3 – Ammonia
NO – Nitric oxide

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

Show raw pollutant concentrations (µg/m³)
PM2.52.29 µg/m³
PM103.64 µg/m³
O329.78 µg/m³
NO23.49 µg/m³
SO20.13 µg/m³
CO133.39 µg/m³
NH30.35 µg/m³
NO0.04 µg/m³