Onjuku Surf Forecast

/ Chiba (19 surf breaks) /

Japan (129 surf breaks) / Lat Long: (35.18° N 140.35° E)

Surf Forecasts:

Onjuku surfForecast / Chiba / Japan

48hr Weather and Surf, issued 2 am Thursday 21 Aug 2025 JST

Forecast update in hr min s Forecast update imminent

Onjuku surf forecast is for near shore open water. Breaking waves will often be smaller at less exposed spots.

Today's Onjuku sea temperature is 26.5° C
(Which is normal for this time of year)

How big are the waves at Onjuku today?

The current surf forecast for Onjuku at 8AM is: 1.2m 5s primary swell from a Southwest direction and 0.7m 5s secondary swell from a South-southwest direction, 0.3m 9s secondary swell from a East direction (forecast issued at 02:00am August 21). The wind direction is predicted to be cross-onshore.

Time (JST) & Date	Wave Height	Wave Period
Morning (21 Aug)	3ft (0.9m)	5s
Afternoon (21 Aug)	2ft (0.6m)	5s
Evening (21 Aug)	2.5ft (0.7m)	6s

Table - waves today at Onjuku. (Swell directed towards the surf break)

Updates in hr min s Forecast update imminent

12 Days Hourly

Print Table

	Thursday 21								Friday 22								Saturday 23
	0 AM	3 AM	6 AM	9 AM	12 PM	3 PM	6 PM	9 PM	0 AM	3 AM	6 AM	9 AM	12 PM	3 PM	6 PM	9 PM	0 AM	3 AM	6 AM	9 AM	12 PM	3 PM	6 PM	9 PM
Rating (10 max)	0	0	0	0	0	0	0	0	1	1	1	1	1	0	0	1	1	1	0	1	0	0	0	0
Swell Height Map See all maps
Wave Height (m) & direction (?)	SSW	SSW	SW	SSW	SSW	SSW	SW	SW	SW	SE	SE	SE	SE	SE	SE	SE	SE	SE	SE	SE	SE	SE	SE	ESE
Period(s) (?)	5	5	5	5	5	5	6	6	6	12	12	12	10	10	10	10	9	9	9	9	9	9	8	8
Wave Graph (?)
Energy (?)	87	88	158	113	85	54	102	84	88	45	47	49	55	58	50	46	43	42	38	48	56	38	42	45
Wind (km/h)	SW	SW	SW	SW	SSW	SSW	SW	SW	WNW	NNE	NE	NE	ENE	ESE	ESE	SSW	NNW	W	ENE	SE	S	SSW	SW	SW
Wind State (?) onshore cross-onshore cross-shore cross-offshore offshore glassy	cross- on	cross- on	cross- on	cross- on	cross- on	cross- on	cross- on	cross- on	glass	cross- off	cross- off	cross- off	cross- off	cross	cross	glass	glass	glass	glass	glass	on	cross- on	cross- on	cross- on
High Tide / height (m)		1:41AM 1.32					4:46PM 1.30			2:48AM 1.38					5:04PM 1.32				3:39AM 1.43				5:22PM 1.34
Low Tide / height (m)					9:23AM 0.14				9:36PM 0.97				10:03AM 0.11				10:11PM 0.85				10:38AM 0.13

	Thursday 21								Friday 22								Saturday 23
Sunrise	-	-	5:01	-	-	-	-	-	-	-	5:01	-	-	-	-	-	-	-	5:03	-	-	-	-	-
Sunset	-	-	-	-	-	-	6:21	-	-	-	-	-	-	-	6:19	-	-	-	-	-	-	-	6:17	-

Rain (mm)	-	-	-	-	-	-	-	1	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-
Temp. °C	26	26	26	29	29	29	28	27	27	26	26	28	29	29	27	27	26	26	26	28	29	29	28	26
Feels °C (?)	27	28	29	33	32	31	32	31	32	30	30	31	32	32	31	33	31	31	31	33	32	30	30	27

Map Icons:
Break
Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)
Wind Speed (km/h)

Recent Eyeball Surf Reports for Chiba

Wind Update Continuing clean conditions at Onjuku (light winds from the SSW at Katsuura 5 km from Onjuku). 1.1m 5s windswell from the SSW with a 0.5m 7s swell from the SE. 2 swells combining to make bigger set waves.
1 hour 25 minutes ago Onjuku

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1 h 25 min ago

9 km/h

SSW

Clean

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