Onagawa
Welcome to Onagawa, a national park located along the breathtaking Sanriku coast in Miyagi Prefecture, Japan. Despite the devastating impact of the tsunami, this beautiful dive site is now making a remarkable recovery. Nestled off Jinghwasan, divers can explore an enchanting fishing area where the mighty Oyashio and Kuroshio currents converge. This convergence creates a remarkable blend of warm and cold currents, providing divers with a truly unique underwater experience. Dive enthusiasts can also immerse themselves in the fascinating world of fixed nets, oysters, and sea squirt shelves.
Prepare to be captivated by the awe-inspiring wall of ascidians, a sight exclusive to the northern region. Divers can encounter dangler fish throughout the year and observe their remarkable spawning rituals. Additionally, the dive site is home to an abundance of distinct northern nudibranchs, dandelions, and anchidnails, adding an extra level of excitement to your underwater exploration.
With visibility reaching up to 10 meters and a maximum depth of 14 meters, this dive site offers an ideal setting for both beginner and advanced divers. Whether you are just starting your diving journey or seeking a new challenge, Onagawa's waters will not disappoint.
Plan your visit to this extraordinary dive site and be a part of Onagawa's remarkable recovery. Experience the wonders of Japan's underwater world like never before.
Prepare to be captivated by the awe-inspiring wall of ascidians, a sight exclusive to the northern region. Divers can encounter dangler fish throughout the year and observe their remarkable spawning rituals. Additionally, the dive site is home to an abundance of distinct northern nudibranchs, dandelions, and anchidnails, adding an extra level of excitement to your underwater exploration.
With visibility reaching up to 10 meters and a maximum depth of 14 meters, this dive site offers an ideal setting for both beginner and advanced divers. Whether you are just starting your diving journey or seeking a new challenge, Onagawa's waters will not disappoint.
Plan your visit to this extraordinary dive site and be a part of Onagawa's remarkable recovery. Experience the wonders of Japan's underwater world like never before.
Diving Conditions Score for Onagawa
7.4
GoodGood diving conditions!
The score is based on a calculation of the current weather and sea conditions.
Dive Site Overview for Onagawa
Depth
14m
Visibility
10m
Experience Level
beginner
advanced
Weather Conditions for Onagawa
Wave Height
0.8m
Wind Speed
3.8 m/s
Water Temp
20°C
Visibility
21.36km
Cloud Cover
65%
Wave Period
8s
Air Temperature
20°C
Precipitation
0 mm
Detailed 7-Day Diving Forecast for Onagawa
Alpha
Dive Score Chart for Onagawa
Best time to dive: 6:00 with score 8.238607092198581/10. Water conditions: Waves 0.84m, Wind 4.7 m/s.Best night dive time: 0:00 with score 8.11230745341615/10.
Chart showing hourly dive conditions including wave height, wind speed, water temperature, and visibility throughout the day.
Sunrise at Onagawa: 06:00
Sunset at Onagawa: 18:00
Optimal diving conditions at Onagawa are affected by daylight hours. Sunrise occurs at 06:00 and sunset at 18:00, which impacts visibility and water temperature for scuba diving and snorkeling.
Best Overall
6:00Score: 8.2/10
Waves: 0.84m (7.05s), Wind: 4.7 m/s
Best Night
0:00Score: 8.1/10
Waves: 0.8m, Wind: 3.8 m/s
Seasonal Analysis for OnagawaAlpha
Historical patterns and best seasons for diving at Onagawa
The dive score combines all factors to rate overall diving conditions throughout the year. Higher scores indicate better diving conditions.
Monthly Dive Score Analysis - Seasonal Diving Conditions
Higher values indicate better diving conditions
Seasonal DiveScore Chart
This chart displays monthly diveScore data throughout the year, showing seasonal patterns. The data is presented as a bar chart with an overlaid line graph.Dive scores range from 1 to 10, with 10 being optimal conditions.
Higher values indicate better diving conditions
Best Season for Onagawa
Winter
Avg. Score: 8.0/10
Winter offers the best overall diving conditions with calmer seas and better visibility, despite cooler temperatures.
Best Months for Onagawa
January
Score: 8.1
December
Score: 8.0
February
Score: 7.9
Ideal Conditions for Onagawa
Water Temp
22.6°C / 72.7°F
July
Visibility
13.4m / 44.0ft
November
Wave Height
1.6m / 5.2ft
December
Wave Period
8.0s
January
Seasonal Insights for Onagawa
Onagawa shows typical northern hemisphere patterns with July being the warmest month (22.6°C) and January the coldest (-2.8°C). The calmest conditions typically occur in December with average wave heights of 1.6m and wave periods of 8.0s. The most comfortable wave conditions are in December with a low wave steepness ratio, creating gentler swells. January offers the longest wave periods (8.0s), creating more comfortable and predictable conditions for boat entries and exits. Ocean currents are slowest in January (0.5m/s) and strongest in January (0.5m/s). May is usually the driest month with 0.0mm of precipitation. For beginners, the best time to visit would be during December to February, when ocean conditions are calmer with long-period waves and currents are typically weaker. Experienced divers might enjoy the challenges and potentially better visibility during the shoulder seasons, with moderate currents that can improve marine life encounters.
Last updated: 1 min. ago - Jun 20, 2026
Note: This dive site is not a verified dive site. Please dive with caution. This dive site might have incorrect information by the community.
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