Australian Government

Bureau of Meteorology


Coastal Waters Forecast 

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IDD11030

Australian Government Bureau of Meteorology
Northern Territory

Coastal Waters Forecast for the Northern Territory

Issued at 2:30 pm CST on Monday 20 July 2026
for the period until midnight CST Thursday 23 July 2026.

Please be aware
Wind and wave forecasts are averages. Wind gusts can be 40 per cent stronger than the forecast, and stronger still in squalls and thunderstorms. Maximum waves can be twice the forecast height.

Warning Information

For latest warnings go to www.bom.gov.au, subscribe to RSS feeds, call 1300 659 210* or listen for warnings on relevant TV and radio broadcasts.

Weather Situation

A weakening ridge of high pressure directs an east to southeasterly flow over coastal waters. Winds will start to ease during the next couple of days, before strengthening again towards the end of the week.

Beagle Bonaparte Coast: WA-NT Border to Cape Fourcroy

Forecast for Monday 20 July until midnight

Winds: Northeast to southeasterly 10 to 15 knots becoming variable about 10 knots in the evening. Seas: Around 1 metre. Swell: Below 0.5 metres. Weather: Clear.

Forecast for Tuesday 21 July

Winds: South to southeasterly about 10 knots tending east to southeasterly 10 to 15 knots before dawn then tending south to southeasterly in the late afternoon. Winds reaching up to 20 knots offshore south of Channel Point during the morning. Seas: Around 1 metre. Swell: Westerly below 1 metre. Weather: Sunny.

Forecast for Wednesday 22 July

Winds: Southeasterly 15 to 20 knots becoming variable about 10 knots in the early afternoon. Seas: Around 1 metre. Swell: Westerly below 1 metre. Weather: Sunny.

Forecast for Thursday 23 July

Winds: East to southeasterly 10 to 15 knots becoming variable about 10 knots during the afternoon. Seas: Around 1 metre. Swell: Below 0.5 metres. Weather: Sunny.

North Tiwi Coast: Cape Fourcroy to Cape Don

Forecast for Monday 20 July until midnight

Winds: East to southeasterly 10 to 15 knots decreasing to about 10 knots in the late evening. Seas: Around 1 metre. Swell: East to northeasterly below 1 metre. Weather: Clear.

Forecast for Tuesday 21 July

Winds: East to southeasterly about 10 knots increasing to 10 to 15 knots in the early morning then decreasing to about 10 knots in the late evening. Seas: Below 1 metre. Swell: East to northeasterly below 1 metre. Weather: Mostly sunny.

Forecast for Wednesday 22 July

Winds: East to southeasterly about 10 knots increasing to 10 to 15 knots in the early morning then decreasing to about 10 knots in the early afternoon. Seas: Below 1 metre. Swell: East to northeasterly around 1 metre. Weather: Mostly sunny.

Forecast for Thursday 23 July

Winds: Southeasterly 10 to 15 knots turning easterly during the day. Seas: Below 1 metre. Swell: East to northeasterly below 1 metre. Weather: Sunny.

Van Diemen Gulf

Forecast for Monday 20 July until midnight

Winds: Northeast to southeasterly 10 to 15 knots becoming variable about 10 knots in the early afternoon. Seas: Below 1 metre. Swell: Below 0.5 metres. Weather: Clear.

Forecast for Tuesday 21 July

Winds: East to northeasterly below 10 knots tending east to southeasterly 10 to 15 knots before dawn then becoming variable about 10 knots in the middle of the day. Seas: Below 1 metre. Swell: Below 0.5 metres. Weather: Sunny.

Forecast for Wednesday 22 July

Winds: East to southeasterly below 10 knots increasing to 10 to 15 knots before dawn then becoming variable about 10 knots in the middle of the day. Seas: Below 1 metre. Swell: Below 0.5 metres. Weather: Sunny.

Forecast for Thursday 23 July

Winds: Variable about 10 knots. Seas: Below 1 metre. Swell: Below 0.5 metres. Weather: Sunny.

Arafura Coast: Cape Don to Cape Wessel

Forecast for Monday 20 July until midnight

Winds: East to southeasterly 15 to 20 knots. Seas: Around 1 metre, increasing to 1 to 1.5 metres offshore east of Maningrida. Swell: Easterly below 1 metre. Weather: Mostly clear.

Forecast for Tuesday 21 July

Winds: Southeasterly 15 to 20 knots. Seas: Around 1 metre, increasing to 1 to 1.5 metres offshore. Swell: Easterly below 1 metre. Weather: Cloud clearing.

Forecast for Wednesday 22 July

Winds: Southeasterly 15 to 20 knots. Seas: 1 to 1.5 metres, decreasing to 1 metre during the morning. Swell: Easterly below 1 metre. Weather: Mostly sunny.

Forecast for Thursday 23 July

Winds: Southeasterly 15 to 20 knots. Seas: Around 1 metre. Swell: Easterly below 1 metre. Weather: Mostly sunny.

Gove Peninsula Coast: Cape Wessel to Cape Arnhem

Forecast for Monday 20 July until midnight

Winds: Southeasterly 15 to 20 knots. Seas: 1 to 1.5 metres. Swell: Southeasterly below 1 metre. Weather: Clear.

Forecast for Tuesday 21 July

Winds: Southeasterly 15 to 20 knots. Seas: 1 to 1.5 metres. Swell: Southeasterly below 1 metre. Weather: Mostly sunny.

Forecast for Wednesday 22 July

Winds: Southeasterly 10 to 15 knots. Seas: Around 1 metre. Swell: East to southeasterly below 1 metre. Weather: Mostly sunny.

Forecast for Thursday 23 July

Winds: Southeasterly 15 to 20 knots. Seas: Around 1 metre. Swell: Below 0.5 metres. Weather: Partly cloudy. 60% chance of showers.

Roper Groote Coast: Cape Arnhem to QLD-NT Border

Forecast for Monday 20 July until midnight

Winds: East to southeasterly 10 to 15 knots, reaching up to 20 knots offshore in the afternoon. Seas: 1 to 1.5 metres. Swell: East to southeasterly below 1 metre. Weather: Clear.

Forecast for Tuesday 21 July

Winds: Southeasterly 10 to 15 knots, reaching up to 20 knots northeast of Groote Eylandt during the morning. Seas: Below 1 metre, increasing to 1 to 1.5 metres north of Numbulwar. Swell: Northeast to southeasterly below 1 metre. Weather: Sunny.

Forecast for Wednesday 22 July

Winds: Southeasterly 10 to 15 knots. Seas: Below 1 metre. Swell: East to northeasterly below 1 metre. Weather: Mostly sunny.

Forecast for Thursday 23 July

Winds: Southeasterly 15 to 20 knots. Seas: Around 1 metre, increasing to 1 to 1.5 metres northeast of Groote Eylandt during the morning. Swell: Northeast to southeasterly below 1 metre. Weather: Partly cloudy.

Darwin Harbour

Forecast for Monday 20 July until midnight

Winds: Variable below 10 knots. Seas: Below 0.5 metres. Swell: Below 0.5 metres. Weather: Clear.

Forecast for Tuesday 21 July

Winds: East to southeasterly below 10 knots becoming west to southwesterly in the evening then becoming southerly in the late evening. Seas: Below 0.5 metres. Swell: Below 0.5 metres. Weather: Sunny.

Forecast for Wednesday 22 July

Winds: Southerly below 10 knots becoming east to southeasterly before dawn then becoming west to southwesterly in the evening. Seas: Below 0.5 metres. Swell: Below 0.5 metres. Weather: Sunny.

Forecast for Thursday 23 July

Winds: Variable below 10 knots. Seas: Below 0.5 metres. Swell: Below 0.5 metres. Weather: Sunny.

The next routine forecast will be issued at 8:30 pm CST Monday.

* Calls to 1300 number cost around 27.5c inc. GST, higher from mobiles or public phones. Marine forecasts are also available on VHF and HF radio. View the radio schedule on www.bom.gov.au/marine

Check the latest Coastal Waters Forecasts for information on wind, wave and weather conditions for neighbouring coastal zones.