Today | Weather | Wednesday, March 18, 2026

Weather in Hillsboro, Oregon

03:26 AM
Now
Cloudy Weather
45° F
Feels Like 45°
Precipitation 47 %
Wind 4 mph
Humidity 98 %
Today
Cloudy Weather
Day 66°
Night 48°
Precipitation 17 %
Wind 6 mph
UV Index (0 - 11+) 2

Hillsboro Weather Forecast Updated

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

Day

52°

Night

39°

Wind

4 mph

UV Index

1

Precipitation

90 %

Air Quality in Hillsboro

NOW
11 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 2.02 µg/m³
PM10 3.47 µg/m³
O3 0.011 ppm
NO2 1.2 ppb
SO2 0 ppb
CO 0.11 ppm
NH3 0.29 µg/m³
NO 0 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)
PM2.52.02 µg/m³
PM103.47 µg/m³
O322.33 µg/m³
NO22.17 µg/m³
SO20.09 µg/m³
CO128.64 µg/m³
NH30.29 µg/m³
NO0 µg/m³