Today | Weather | Thursday, July 23, 2026

Weather in South Portland, Maine

03:31 AM
Now
Night
55° F
Feels Like 55°
Precipitation 0 %
Wind 4 mph
Humidity 92 %
Today
Cloudy Weather
Day 77°
Night 54°
Precipitation 2 %
Wind 9 mph
UV Index (0 - 11+) 9

Warning: High UV Index Today: 9

High risk of harm from unprotected sun exposure. Take precautions: wear a hat, sunglasses, and apply sunscreen regularly if you’ll be outdoors for extended periods.

South Portland Weather Forecast Updated

Air Quality in South Portland

NOW
20 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 0.88 µg/m³
PM10 1.06 µg/m³
O3 0.022 ppm
NO2 1.9 ppb
SO2 0.3 ppb
CO 0.09 ppm
NH3 0.21 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)
PM2.50.88 µg/m³
PM101.06 µg/m³
O342.68 µg/m³
NO23.66 µg/m³
SO20.81 µg/m³
CO101.5 µg/m³
NH30.21 µg/m³
NO0 µg/m³