Today | Weather | Wednesday, September 16, 2026

Active Weather Warnings

Flood Watch

Weather in Honolulu, Hawaii

07:04 PM

Now

81° F

Feels Like 84°

Precipitation 33 %

Wind 13 mph

Humidity 77 %

Today

Day 88°

Night 79°

Precipitation 90 %

Wind 14 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.

Honolulu Weather Forecast Updated

Last updated on September 16, 2026 at 5:42 PM

Weather Forecast History

Last Year's Weather on This Day (September 16, 2025)

Day

88°

Night

75°

Wind

16 mph

UV Index

100

Precipitation

49 %

Air Quality in Honolulu

NOW

17 AQI

Good air quality Dominant pollutant: PM_2.5

Pollutant Concentrations:

PM_2.5 4.13 µg/m³

PM₁₀ 12.57 µg/m³

O₃ 0.017 ppm

NO₂ 0.2 ppb

SO₂ 0.1 ppb

CO 0.09 ppm

NH₃ 0 µg/m³

NO 0 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 – 4.13 µg/m³

PM₁₀ – 12.57 µg/m³

O₃ – 33.43 µg/m³

NO₂ – 0.33 µg/m³

SO₂ – 0.25 µg/m³

CO – 106.71 µg/m³

NH₃ – 0 µg/m³

NO – 0 µg/m³

View Hourly Air Quality Forecast

Weather Alerts and Warnings for Honolulu

Severe Future Possible

Flood Watch

Flood Watch issued September 16 at 4:03PM HST until September 18 at 6:00AM HST by NWS Honolulu HI

Sep 16, 6:00 PM → Sep 18, 6:00 AM

Remnant moisture from former Tropical Storm Norbert will bring
periods of moderate to heavy showers to the Hawaiian Islands tonight
through Friday morning.

WHAT: Flash flooding caused by excessive rainfall is possible.

WHERE: All main Hawaiian Islands.

WHEN: Through late Thursday night.

IMPACTS: Flood prone roads and other low lying areas may be closed
due to elevated runoff and overflowing streams. Urban areas may
receive more significant flooding and property damage due to rapid
runoff.

ADDITIONAL DETAILS:
- A band of remnant moisture from Norbert will move east across the
islands tonight into Friday, bringing moderate to locally heavy
showers. There is a slight chance of thunderstorms on Thursday as
well, which could produce briefly higher rain rates, increasing
the risk of flash flooding.

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You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued.

Updated: Sep 16, 5:42 PM Source: NWS Alert