What is Diamond Head Beach water quality like in January?

January falls within Hawaii's wet season. Diamond Head Beach typically sees higher rainfall during this period, which increases the chance of bacteria-laden runoff entering the ocean. Advisory risk is moderate. Check the live advisory status and avoid swimming for 72 hours after heavy rain.

Does it rain at Diamond Head Beach in January?

Diamond Head Beach averages approximately 3.3 inches of rain in January. This is part of Hawaii's wet season (October through March), when rainfall is more frequent and heavier. Rainfall directly affects water quality through increased runoff carrying bacteria into the ocean.

Is January a good time to visit Diamond Head Beach?

January brings wetter conditions and higher advisory risk to Diamond Head Beach. The beach is still worth visiting, but pay closer attention to weather and water quality. Avoid the ocean for 72 hours after heavy rain. Monitor the live DOH advisory status at the top of this page.

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Oʻahu · South Shore

Diamond Head Beach Water Quality in January

What to expect for water quality, rainfall, and ocean conditions

Checking live advisories…

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January Conditions at Diamond Head Beach

January Advisory Risk Moderate

Even at lower-risk beaches like Diamond Head Beach, january brings more rainfall that can temporarily affect water quality. Avoid swimming after storms and check the live status above.

🌧️ Rainfall & Runoff

January is part of Hawaii's wet season (October through March). Diamond Head Beach sees approximately 3.3 inches of rain this month. Heavier rainfall means more runoff entering coastal waters, carrying bacteria from inland areas. Streams and storm drains near the beach can discharge after rain events.

🌊 Ocean Conditions

South-facing shores are generally calmer in January with smaller swells. Diamond Head Beach benefits from protection from the dominant winter north swells. Water temperature around 75-77°F. Conditions are often more suitable for swimming and snorkeling.

👥 Crowd Levels

High. January is peak tourist season with holiday travelers and winter visitors. Diamond Head Beach can be crowded, especially mid-morning to afternoon.

📌 January Notes

•Humpback whale season is active (November through April). Whales are frequently visible from shore across all islands.

•New Year is one of Hawaii's busiest periods. Book activities early and arrive at beaches before 9am for parking.

⚠

If It Looks Brown, Don't Swim

Never enter the ocean when the water appears brown or murky, even if no advisory is posted. Hawaii is often slow to test beaches and update advisories — not every beach is monitored. After heavy rain, wait at least 72 hours and until the water clears before swimming.

Learn more about brown water advisories →

⚠️ The 72-Hour Rain Rule

The Hawaii Department of Health recommends staying out of the ocean for at least 72 hours after heavy rain. In january, rainfall is more frequent and can produce significant contaminated runoff. Be especially cautious after storms.

Book Tours & Activities

When conditions are clear, Diamond Head Beach has excellent ocean activities. Check the water quality above, then book with confidence.

⛳ Tours & Activities Near Diamond Head Beach

Browse snorkeling, boat tours, and ocean adventures in the area.

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🏄 Snorkeling & Ocean Tours

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Diamond Head Beach — Other Months

Diamond Head Beach in February→ Diamond Head Beach in March→ Diamond Head Beach in April→ Diamond Head Beach in May→ Diamond Head Beach in June→ Diamond Head Beach in July→ Diamond Head Beach in August→ Diamond Head Beach in September→ Diamond Head Beach in October→ Diamond Head Beach in November→ Diamond Head Beach in December→

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Safe to Swim Hawaii provides water quality information based on publicly available DOH data and seasonal patterns. This is not medical or safety advice. Always check current conditions, obey posted signs, and use your own judgment before entering the ocean. Privacy Policy