Christchurch Coast · Today

Sumner Beach

Updated Wed, Sep 23, 11:40 AM GMT+12

When to go

Around 6:00 PM

Looks good · Low confidence

1.0–1.0 ft · Offshore waves · not face height

Wind: 5.8 kt · offshore

Forecast details

Light wind should keep the water smoother.

Other wind windows

Plan around the wind

The best available upcoming daylight wind sample to compare with the wave evidence. This compares wind only; wave size, tide suitability, and hazards can change your choice.

4:00 PM–6:00 PM · Pacific/Auckland
Strong wind · up to 10.2 kt · reported gusts up to 26.0 kt
Caution: This is the best available wind comparison, not a favorable-wind label. Strong wind remains in the selected evidence.
Offshore waves: 1.0–1.2 ft across the period. Surf height unavailable. Tide data unavailable.
Wind source time: Sep 23, 11:45 AM GMT+12. This is not the model run issue time.

How these periods are chosen

The planner prefers three consecutive hourly samples covering two daylight hours, but retains shorter one- or two-sample evidence when that is all the forecast provides. Light wind means at most 6 kt. Moderate offshore means at most 12 kt from land toward the sea when shore orientation is verified. Strong wind or known gusts of 20 kt or more remain visible as cautions instead of making the entire comparison disappear. These are comparison labels, not locally tested surf-quality or safety ratings. Missing gusts remain unknown. Terrain shelter, currents, closures, and your ability are not assessed.

Forecast confidence

Returned marine grid point is 9.5 km from the mapped spot. Provider grid resolution is not established for this response.
Reference model hour: 0 hours from now; historical residuals do not measure forecast lead-time error.
No accepted local model for these inputs: missing history, unsupported direction/period/height, or failed historical validation.
Tide unavailable: assessment incomplete, especially at shallow reef breaks.
A mapped coordinate does not establish nearshore grid resolution or terrain/shelter accuracy.

Wind SSW 12.3 kt

Tide Unavailable

Wave, wind and tide details

Offshore model swellSE 0.5 ft @ 4sValid 2026-09-23 12:00 · Pacific/AucklandMarine grid -43.5417, 172.8750 · offshore model, not a local measurement

Offshore model sea1.4 ft @ 3.7sSignificant wave height including wind waves and swell; not breaking surfValid 2026-09-23 12:00 · Pacific/Auckland

Model windSSW 12.3 ktoffshoreValid 2026-09-23 12:00 · Pacific/Auckland10.0 kt offshore component

TideUnavailableunavailableNo verified local tide station connected; no tide height estimated

Surf height unavailable. Coastal and offshore waves are not breaking-wave heights.

Surf and wind

Recommended window: No recommended window

Breaking surf is not reliably resolved. Hourly offshore swell and wind inputs are listed below.

Hourly forecast

Hourly surf forecast for Sumner Beach
Time	Wind	Tide	Offshore swell
12 AM	SW 6.6 ktoffshore	Unavailableunavailable	NE 0.6 ft @ 4s
1 AM	SSW 9.8 ktoffshore	Unavailableunavailable	ENE 0.6 ft @ 4s
2 AM	SW 10.6 ktoffshore	Unavailableunavailable	ESE 0.5 ft @ 3s
3 AM	SW 10.5 ktoffshore	Unavailableunavailable	SSE 0.5 ft @ 3s
4 AM	SW 10 ktoffshore	Unavailableunavailable	SE 0.5 ft @ 3s
5 AM	SW 8.4 ktoffshore	Unavailableunavailable	SE 0.5 ft @ 4s
6 AM	SW 6.3 ktoffshore	Unavailableunavailable	SE 0.5 ft @ 4s
7 AM	SW 6.2 ktoffshore	Unavailableunavailable	ESE 0.5 ft @ 6s
8 AM	SW 8.3 ktoffshore	Unavailableunavailable	ESE 0.5 ft @ 7s
9 AM	SSW 10.2 ktoffshore	Unavailableunavailable	E 0.5 ft @ 8s
10 AM	SW 11.2 ktoffshore	Unavailableunavailable	ESE 0.5 ft @ 7s
11 AM	SW 11.5 ktoffshore	Unavailableunavailable	ESE 0.5 ft @ 5s
Noon	SSW 12.3 ktoffshore	Unavailableunavailable	SE 0.5 ft @ 4s
1 PM	SSW 12.4 ktoffshore	Unavailableunavailable	SE 0.5 ft @ 4s
2 PM	SSW 12 ktoffshore	Unavailableunavailable	SE 0.5 ft @ 5s
3 PM	SSW 11.3 ktoffshore	Unavailableunavailable	SE 0.5 ft @ 5s
4 PM	SSW 10.2 ktoffshore	Unavailableunavailable	SSE 0.5 ft @ 4s
5 PM	SSW 8.4 ktoffshore	Unavailableunavailable	S 0.6 ft @ 3s
6 PM	SW 5.8 ktoffshore	Unavailableunavailable	SSW 0.7 ft @ 3s
7 PM	SW 4.1 ktoffshore	Unavailableunavailable	S 0.7 ft @ 3s
8 PM	WSW 3.5 ktoffshore	Unavailableunavailable	SSE 0.6 ft @ 4s
9 PM	W 3 ktoffshore	Unavailableunavailable	SE 0.6 ft @ 4s
10 PM	WSW 2.6 ktoffshore	Unavailableunavailable	SE 0.6 ft @ 4s
11 PM	WSW 2.5 ktoffshore	Unavailableunavailable	SE 0.6 ft @ 4s

12 AMUnavailable

WindSW 6.6 ktoffshoreTideUnavailableunavailableOffshore swellNE 0.6 ft @ 4s

1 AMUnavailable

WindSSW 9.8 ktoffshoreTideUnavailableunavailableOffshore swellENE 0.6 ft @ 4s

2 AMUnavailable

WindSW 10.6 ktoffshoreTideUnavailableunavailableOffshore swellESE 0.5 ft @ 3s

3 AMUnavailable

WindSW 10.5 ktoffshoreTideUnavailableunavailableOffshore swellSSE 0.5 ft @ 3s

4 AMUnavailable

WindSW 10 ktoffshoreTideUnavailableunavailableOffshore swellSE 0.5 ft @ 3s

5 AMUnavailable

WindSW 8.4 ktoffshoreTideUnavailableunavailableOffshore swellSE 0.5 ft @ 4s

6 AMUnavailable

WindSW 6.3 ktoffshoreTideUnavailableunavailableOffshore swellSE 0.5 ft @ 4s

7 AMUnavailable

WindSW 6.2 ktoffshoreTideUnavailableunavailableOffshore swellESE 0.5 ft @ 6s

8 AMUnavailable

WindSW 8.3 ktoffshoreTideUnavailableunavailableOffshore swellESE 0.5 ft @ 7s

9 AMUnavailable

WindSSW 10.2 ktoffshoreTideUnavailableunavailableOffshore swellE 0.5 ft @ 8s

10 AMUnavailable

WindSW 11.2 ktoffshoreTideUnavailableunavailableOffshore swellESE 0.5 ft @ 7s

11 AMUnavailable

WindSW 11.5 ktoffshoreTideUnavailableunavailableOffshore swellESE 0.5 ft @ 5s

NoonUnavailable

WindSSW 12.3 ktoffshoreTideUnavailableunavailableOffshore swellSE 0.5 ft @ 4s

1 PMUnavailable

WindSSW 12.4 ktoffshoreTideUnavailableunavailableOffshore swellSE 0.5 ft @ 4s

2 PMUnavailable

WindSSW 12 ktoffshoreTideUnavailableunavailableOffshore swellSE 0.5 ft @ 5s

3 PMUnavailable

WindSSW 11.3 ktoffshoreTideUnavailableunavailableOffshore swellSE 0.5 ft @ 5s

4 PMUnavailable

WindSSW 10.2 ktoffshoreTideUnavailableunavailableOffshore swellSSE 0.5 ft @ 4s

5 PMUnavailable

WindSSW 8.4 ktoffshoreTideUnavailableunavailableOffshore swellS 0.6 ft @ 3s

6 PMUnavailable

WindSW 5.8 ktoffshoreTideUnavailableunavailableOffshore swellSSW 0.7 ft @ 3s

7 PMUnavailable

WindSW 4.1 ktoffshoreTideUnavailableunavailableOffshore swellS 0.7 ft @ 3s

8 PMUnavailable

WindWSW 3.5 ktoffshoreTideUnavailableunavailableOffshore swellSSE 0.6 ft @ 4s

9 PMUnavailable

WindW 3 ktoffshoreTideUnavailableunavailableOffshore swellSE 0.6 ft @ 4s

10 PMUnavailable

WindWSW 2.6 ktoffshoreTideUnavailableunavailableOffshore swellSE 0.6 ft @ 4s

11 PMUnavailable

WindWSW 2.5 ktoffshoreTideUnavailableunavailableOffshore swellSE 0.6 ft @ 4s

Tide

Local tide station unavailable

Tide predictions are unavailable for this period.

About this spot

Model-grid forecast requested at the mapped coordinate; reef, headland, and nearshore transformations are unresolved. Beach/river bar break. Published named-break coordinate replaces the former region fallback; the source describes ENE swell and southwest offshore wind.

Mapped spot coordinate: -43.56, 172.76.

South Island · Pegasus Bay east-northeast-facing beach and Avon-Heathcote river-bar coast · Ocean-facing bearing 67.5° · Location provenance

Model request point: Sumner Beach (-43.56, 172.76). Model output times describe valid conditions; the provider does not expose the model run issue time in this response.

Forecast sources

Data coverage 2/6 sources

Source availability is not forecast accuracy. Where an empirical model passes historical testing, its error and interval coverage are shown above. Source count cannot increase that confidence.

Coverage tier B · NEW_ZEALAND · spot-level model point

MetService New Zealand Surf Forecasts
The checked MetService public marine/surf response exposes an HTML application shell but no stable named-spot payload, timestamp schema, units, or update contract; no forecast is scraped.UnavailableNo source time
New Zealand Regional Wave Buoy Pages
Environment Canterbury documents its Banks Peninsula buoy identity, units, three-hour transmission cadence, and 76 m depth, but the direct anonymous response available to the product is a 212-byte Incapsula challenge. South Island Waves returned an empty public list and no observations, so no buoy value is connected.UnavailableNo source time
NIWA Tide Forecasting API
NIWA tide requests require an API key; no credential bypass is attempted and no station, datum, timezone, or current value is available.UnavailableNo source time
LINZ Tide Predictions and Sea-Level Data
LINZ is retained as an official tide-table reference, but no spot-specific station, distance, chart datum, timezone, and current response is connected.UnavailableNo source time
Open-Meteo Marine API
1 of 1 configured model points availableCurrentSep 23, 11:45 AM GMT+12
Open-Meteo Weather API
1 of 1 configured model points availableCurrentSep 23, 11:45 AM GMT+12
Surf-Forecast public pages
Spot discovery and break-specific HTML fallbackNot applicableNo source time
Surfline public spot pages
Break-specific comparison, cams, and metadataNot applicableNo source time

How best guesses are made

Best guesses combine usable wave and wind evidence, with qualitative confidence and specific limitations. A missing tide or local surf-height model does not prevent useful guidance. Tide levels use the named station datum; their effect at this break remains uncertain. Wind direction is relative to the mapped beach orientation, without calibrated terrain or shelter effects. The comparison is a heuristic, not a measured quality rating.