Today | Weather | Friday, September 18, 2026

Weather in Portland, Oregon

12:37 PM
Now
Cloudy Weather
68° F
Feels Like 73°
Precipitation 0 %
Wind 6 mph
UV Index (0 - 11+) 4
Humidity 61 %
Today
Cloudy Weather
Day 73°
Night 54°
Precipitation 1 %
Wind 4 mph
UV Index (0 - 11+) 4

Portland Weather Forecast Updated

Last updated on
Weather Forecast History
Last Year's Weather on This Day (September 18, 2025)
Cloudy Night

Day

73°

Night

52°

Wind

7 mph

Precipitation

0 %

Air Quality in Portland

NOW
34 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 3.36 µg/m³
PM10 6.1 µg/m³
O3 0.036 ppm
NO2 0.4 ppb
SO2 0.2 ppb
CO 0.13 ppm
NH3 0.12 µg/m³
NO 0.21 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)
PM2.53.36 µg/m³
PM106.1 µg/m³
O371.04 µg/m³
NO20.84 µg/m³
SO20.4 µg/m³
CO146.27 µg/m³
NH30.12 µg/m³
NO0.21 µg/m³