Today | Weather | Tuesday, June 9, 2026

Active Weather Warnings

Beach Hazards Statement

Weather in Costa Mesa, California

04:49 PM

Now

73° F

Feels Like 75°

Precipitation 0 %

Wind 8 mph

UV Index (0 - 11+) 3

Humidity 63 %

Today

Day 73°

Night 63°

Precipitation 0 %

Wind 7 mph

UV Index (0 - 11+) 11

Warning: Extreme UV Index Today: 11+

Overexposure to the sun's harmful UV rays can cause sunburn and increase the risk of developing skin cancer, including melanoma. Protect yourself by wearing clothing that covers your skin, sunglasses, and a hat. Apply a broad-spectrum sunscreen with an SPF of 30 or higher every two hours, even on cloudy days. Minimize direct sun exposure during peak hours (10 AM to 4 PM) to reduce the risk.

Costa Mesa Weather Forecast Updated

19 minutes ago

Last updated on June 09, 2026 at 4:29 PM

Weather Forecast History

Last Year's Weather on This Day (June 9, 2025)

Day

68°

Night

61°

Wind

7 mph

UV Index

Precipitation

2 %

Air Quality in Costa Mesa

NOW

35 AQI

Good air quality Dominant pollutant: O₃

Pollutant Concentrations:

PM_2.5 5.78 µg/m³

PM₁₀ 15.76 µg/m³

O₃ 0.038 ppm

NO₂ 0.1 ppb

SO₂ 0.3 ppb

CO 0.08 ppm

NH₃ 0 µg/m³

NO 0.05 µg/m³

PM_2.5 – 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)

PM_2.5 – 5.78 µg/m³

PM₁₀ – 15.76 µg/m³

O₃ – 75.01 µg/m³

NO₂ – 0.23 µg/m³

SO₂ – 0.81 µg/m³

CO – 92.19 µg/m³

NH₃ – 0 µg/m³

NO – 0.05 µg/m³

View Hourly Air Quality Forecast

Weather Alerts and Warnings for Costa Mesa

Moderate Expected Likely

Beach Hazards Statement

Beach Hazards Statement issued June 9 at 12:39PM PDT until June 11 at 5:00PM PDT by NWS San Diego CA

Jun 9, 12:39 PM → Jun 11, 5:00 PM

WHAT: South swell from 190 degrees with a period of 18 to 20
seconds will generate surf of 4 to 7 feet with sets up to 9
feet along south-facing beaches. High rip current risk.

WHERE: San Diego County Coastal Areas and Orange County
Coastal Areas.

WHEN: From late Monday night through Thursday afternoon.

IMPACTS: Hazardous swimming conditions and a high rip current
risk. If you become caught in a rip current, yell for help.
Remain calm and do not exhaust yourself and stay afloat while
waiting for help. If you have to swim out of a rip current,
SWIM PARALLEL TO SHORE and back toward the beach when
possible. Do not attempt to swim directly against a rip
current as you will tire quickly.

ADDITIONAL DETAILS: Highest surf will be at south-facing
beaches and peak Tuesday and Wednesday. Swell and surf will
slowly subside beginning Thursday with a shorter period, but
will remain elevated into Friday.

+ Read More

Remain out of the water to avoid hazardous swimming conditions.

Updated: Jun 9, 4:29 PM Source: NWS Alert