Today | Weather | Tuesday, April 21, 2026

Weather in Carlsbad, California

04:37 PM
Now
Cloudy Weather
68° F
Feels Like 66°
Precipitation 34 %
Wind 10 mph
UV Index (0 - 11+) 1
Humidity 61 %
Today
Partly Sunny with Showers
Day 72°
Night 52°
Precipitation 49 %
Wind 9 mph
UV Index (0 - 11+) 10

Warning: High UV Index Today: 10

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.

Carlsbad Weather Forecast Updated

40 minutes ago
Last updated on
Weather Forecast History
Last Year's Weather on This Day (April 21, 2025)
Cloudy Weather

Day

68°

Night

52°

Wind

8 mph

UV Index

10

Precipitation

0 %

Air Quality in Carlsbad

NOW
43 AQI
Good air quality Dominant pollutant: O3

Pollutant Concentrations:

PM2.5 2.63 µg/m³
PM10 6.74 µg/m³
O3 0.046 ppm
NO2 0.1 ppb
SO2 0.1 ppb
CO 0.11 ppm
NH3 0 µg/m³
NO 0.02 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)
PM2.52.63 µg/m³
PM106.74 µg/m³
O390.49 µg/m³
NO20.14 µg/m³
SO20.35 µg/m³
CO120.54 µg/m³
NH30 µg/m³
NO0.02 µg/m³