Surf Forecasts:
Costellos surf forecast from 9 Aug 2026:
- Best quality surf: Wednesday 12 Aug, 11PM (local time) - 4ft (1.2m), 5s period, S swell with cross-offshore winds.
- Most powerful swell: Wednesday 12 Aug, 11PM (local time) - 4ft (1.2m), 5s period, S swell with 70 kJ wave energy.
- Next surfable swell (1★+): Wednesday 12 Aug, 11PM (local time) - 4ft (1.2m), 5s period with S swell.
Best Forecast Surf Conditions for Costellos this week:
The surf forecast for Costellos over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Wednesday (Aug 12) at 11PM. The primary swell is predicted to be 1.2m and 5s period with a secondary swell of 0.1m and 8s. Another secondary swell of 0.1m and 14s is also forecast. The wind is predicted to be cross-offshore as the swell arrives.
The most powerful waves expected at Costellos in the next 16 days are 1.2m 5s and forecast to arrive on Wednesday (Aug 12) at 11PM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.6m 3s period and expected on Saturday (Aug 15) at 2PM.
| Wave Type | Time (EDT) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 11PM (Wed 12th Aug) | 4ft (1.2m) 5s |
| Best Surf | 11PM (Wed 12th Aug) | 4ft (1.2m) 5s |
| Most Powerful | 11PM (Wed 12th Aug) | 4ft (1.2m) 5s |
Table - best surf conditions forecast for Costellos over the next 16 days.
The Lowdown
G’day, I’m Rusty.
Alright, let’s be honest from the get-go: this stretch from Sunday the 9th of August right through to about Thursday the 20th of August is pretty much a write-off for Costellos. We’re looking at a long, painful gap of nearly two weeks with barely a ripple worth paddling for. The swell energy is weak as dishwater, mostly sitting between 5 and 87 (combined energy), and the heights are tiny—think 0.3 ft to 2 ft. Some days you’ll get a clean session with offshore or cross-off winds, but there’s just no power behind it. The odd squirt of a 4 ft wave on the 17th afternoon is still junk with a 5-second period and messy cross-shore chop. Honestly, this is more kite-surfing territory than paddle surfing if you’re desperate.
Now, the water temperature is about average for the time of year, nothing unusual to report there.
Come Saturday the 22nd of August, things start to grumble. The morning shows a 5 ft SE swell with a 5-second period, energy ramping to 105 (moderate), and clean WNW cross-off winds. It’s still marginal. By the afternoon, the swell pushes to 6 ft from the SE with a 6-second period, energy jumping to 406 (strong), and clean WNW cross-off breeze. That’s a step up, but still short period and lumpy.
The real standout, and I mean the only one worth circling on your calendar, is Sunday the 23rd of August. The morning session at Costellos has a 5 ft swell from the NE with a 7-second period, 260 (strong) combined energy, and light S cross-off winds that’ll leave it clean. The wind is light, the wave height is solid for a reef break, and it’s showing good surf conditions. The NE direction is a classic for this spot. Yes, it’s a bit short period, but the energy is there and it’ll peel nicely on the reef. Afternoon sees a similar 6 ft NE swell with 364 (strong) energy, but the wind swings S cross-shore, putting a slight chop on it. Still, the morning is the pick—expect a few others out, but it’s not going to be packed.
Monday the 24th of August offers a backup: 5 ft from the ENE with a 9-second period, 293 (strong) energy, and a moderate WSW offshore wind. Clean again, but a touch smaller and the period is longer, which can make it a bit fat at times. Still, a solid option if you missed Sunday.
Long story short: the first two weeks are a dud, but Sunday the 23rd morning is your best shot. Get out there.
Rusty
Short Range ForecastLight rain (total 3mm), mostly falling on Sat night. Warm (max 33°C on Sun afternoon, min 20°C on Mon night). Wind will be generally light. | Days 5-7 Weather SummaryLight rain (total 9mm), mostly falling on Wed morning. Warm (max 27°C on Thu afternoon, min 15°C on Thu night). Wind will be generally light. | ||||||||||||||||||
Sunday 9 | Monday 10 | Tuesday 11 | Wednesday 12 | Thursday 13 | Friday 14 | ||||||||||||||
Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | |
Swell Height Map |  |  |  |  |  |  |  | ||||||||||||
Wave Height (m) Direction Period (s) | SE 7 | SSE 7 | SSE 7 | SE 10 | SE 10 | SSE 3 | SSE 4 | SE 9 | SE 9 | ESE 9 | SSE 7 | SE 14 | S 5 | SSE 5 | SE 5 | ESE 10 | SE 10 | ESE 10 | ESE 9 |
Wave Graph  | |||||||||||||||||||
 kJ | 10 | 5 | 5 | 4 | 4 | 6 | 7 | 3 | 3 | 8 | 5 | 8 | 47 | 15 | 12 | 9 | 14 | 9 | 9 |
Wind (km/h) | |||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | off | off | off | cross-off | cross-on | cross-on | off | cross-off | cross-off | glassy | cross-on | on | cross-off | off | off | cross-off | cross-off | cross-off | off |
High Tide | 8:30AM2.95m | 8:47PM3.49m | 9:32AM3.10m | 9:47PM3.62m | 10:29AM3.26m | 10:44PM3.73m | 11:22AM3.41m | 11:38PM3.78m | 12:13PM3.52m | 00:30AM3.77m | 1:01PM3.57m | 1:20AM3.68m | |||||||
Low Tide | 2:17AM0.46m | 2:27PM0.72m | 3:19AM0.32m | 3:30PM0.59m | 4:16AM0.18m | 4:29PM0.44m | 5:10AM0.07m | 5:24PM0.31m | 6:00AM0.01m | 6:17PM0.23m | 6:49AM0.03m | 7:08PM0.21m | |||||||
 |  | |  | |  | | | |  |  |  | | | | | | | | |
 | — | 5:41 | — | — | 5:43 | — | — | 5:43 | — | — | 5:45 | — | — | 5:46 | — | — | 5:47 | — | — |
 | 7:54 | — | 7:53 | — | — | 7:52 | — | — | 7:51 | — | — | 7:50 | — | — | 7:47 | — | — | 7:46 | — |
mm | 2 | — | — | — | — | — | 1 | — | — | — | 6 | 2 | — | 1 | — | — | — | — | — |
Temp °C | 24 | 29 | 33 | 29 | 25 | 26 | 27 | 27 | 30 | 26 | 18 | 19 | 18 | 24 | 27 | 23 | 20 | 23 | 22 |
Feels °C | 27 | 29 | 30 | 28 | 24 | 24 | 27 | 26 | 27 | 25 | 18 | 19 | 18 | 24 | 26 | 21 | 15 | 18 | 19 |
Swell 1 Height (m) Direction Period (s) | SSE 5 | S 5 | SSE 7 | SE 4 | SE 10 | SE 10 | SSE 4 | SSE 4 | SE 9 | ESE 9 | SE 8 | SE 8 | SE 8 | SSE 5 | SE 5 | ESE 10 | SE 10 | ESE 10 | SE 4 |
| kJ | 10 | 2 | 5 | 1 | 4 | 4 | 7 | 1 | 3 | 8 | 3 | 3 | 3 | 15 | 12 | 9 | 14 | 9 | 4 |
Swell 2 Height (m) Direction Period (s) | SE 7 | SSE 7 | E 9 | SE 7 | — | E 8 | SE 10 | SE 9 | S 4 | SSE 6 | SSE 7 | SE 14 | SE 14 | SE 10 | ESE 10 | ESE 5 | SE 4 | SSE 8 | ESE 9 |
| kJ | 7 | 5 | 2 | 2 | — | 1 | 4 | 3 | 2 | 3 | 5 | 8 | 8 | 4 | 9 | 2 | 1 | 6 | 9 |
Swell 3 Height (m) Direction Period (s) | E 8 | E 8 | E 8 | SE 10 | E 8 | — | E 8 | E 8 | S 6 | E 15 | E 14 | E 11 | E 11 | SE 14 | SE 13 | SSE 5 | SE 13 | SE 4 | SSE 8 |
| kJ | 1 | 1 | 1 | 4 | 1 | — | 1 | 1 | 1 | 4 | 4 | 2 | 2 | 8 | 7 | 3 | 7 | 1 | 7 |
Wind waves Height (m) Direction Period (s) | — | — | — | — | SE 7 | SSE 3 | WSW 2 | WSW 3 | NW 2 | NNW 2 | — | SSE 3 | S 5 | — | NW 3 | NW 3 | WNW 3 | — | — |
| kJ | — | — | — | — | 2 | 6 | 1 | 1 | 1 | 1 | — | 3 | 47 | — | 2 | 3 | 1 | — | — |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 163 | 227 | 405 | 192 | 627 | 601 | 273 | 247 | 273 | 619 | 620 | 1711 | 0 | 186 | 620 | 493 | 232 | 1049 | 186 |
Best forecast wave conditions in New Hampshire | |||||||||||||||||||
Best forecast wave conditions in United States | |||||||||||||||||||
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Information about the Costellos Surf forecast
The above surf forecast table for Costellos provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Costellos can be found by selecting the local surf guide option on the grey menu. Our Costellos surf forecast is unique since it includes wave energy (power) that defines the real feel of the surf rather than just the height or the period. If you surf the same spot (Costellos) regularly then make a mental note of the wave energy from the surf forecast table each time you go. Very soon you may start to choose your surf days based on the wave energy alone combined with our forecast of favourable offshore wind conditions. Our star ratings will help here and of course you will also find the usual wave height and period predictions on our surf forecasts as well as a full break down of the swell components under our advanced users option (to reveal that, click the little Einstein character under the tide times).
Further information to help with frequently asked questions about our surf forecast for Costellos may be found under the help tab on the top menu and also by moving your mouse over the question marks on the surf forecast table itself. Please always bear in mind that the forecast is for near-shore open water and local factors at each surf break influence the actual breaking wave height, such as the beach / reef profile, water depths offshore and shelter.
Costellos is 5 km (3 miles) from Hampton. If you plan a vacation in New Hampshire, look for hotels and other accommodation in Hampton. Hampton has rooms for a wide range of budgets as well as car hire and transport links.
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