When the snapper come in 2026, what 41 springs of sea temperature say

The snapper are coming, but not yet. In the second week of September the water in the Motuihe Channel, the closest of the six spots on our live conditions tool to downtown Auckland, sat around 14.4 degrees on the NASA satellite analysis. Snapper start feeding properly at 16 degrees and spawn once the water holds 18, the thresholds our guides use. On the full 41 year record the inner Gulf reaches 16 degrees around 1 November and 18 degrees around 2 December. In the last ten springs it has got there around 24 October and 17 November, and this year the water is running about 0.9 degrees warmer than average for the date, so the recent dates are the ones to plan on.

The temperatures on the tool come from the NASA Jet Propulsion Laboratory’s MUR analysis, which blends satellite and buoy readings onto a 1 kilometre grid every day. For history we needed something that reaches back further, so we used NOAA’s Coral Reef Watch analysis, a 5 kilometre daily product that runs from 1985, and pulled every day of it for the six tool spots. For each spring since 1985 we then found the first day the seven day average reached 16, 17 and 18 degrees, and compared this year’s reading on 11 September with the same date in every earlier year. That gives 41 completed springs plus this one, so today’s reading is ranked among 42 years. The two products differ slightly in the shallow inner Gulf, so the table below compares like with like inside the 41 year record, and the tool gives you the live 1 kilometre number for today.

Spot	Water on 11 Sep 2026	Average for the date, 1985 to 2025	Rank of 2026 in 42 years
Bay of Islands	16.0°C	15.2°C	3rd warmest of 42
Whangaparaoa	14.7°C	13.8°C	3rd warmest of 42
Motuihe Channel	14.6°C	13.7°C	4th warmest of 42
Great Barrier Island	15.3°C	14.7°C	7th warmest of 42
Whitianga	15.1°C	14.5°C	4th warmest of 42
Kaipara Harbour entrance	14.8°C	14.2°C	5th warmest of 42

On 11 September the seven day mean in the Coral Reef Watch record was above the 41 year average for the date at all six spots, by between 0.6 and 0.9 degrees. The Bay of Islands read 16.0 against an average of 15.2, the third warmest 11 September in the 42 years. Whangaparaoa read 14.7 against 13.8, also third warmest. Motuihe read 14.6 against 13.7, fourth warmest, and only 2024, 2022 and 2005 were warmer on the date. Great Barrier, Whitianga and the Kaipara entrance were all between 0.6 and 0.7 of a degree above average. That is in line with the NIWA figure of about half a degree above average for the north of the North Island. It is a warm start, not a freak one.

Spot	Average first day at 16°C	Average first day at 18°C	Earliest and latest 18°C, 1985 to 2025
Bay of Islands	19 October	11 December	5 November to 24 January
Whangaparaoa	1 November	4 December	6 November to 11 January
Motuihe Channel	1 November	2 December	1 November to 10 January
Great Barrier Island	30 October	10 December	11 November to 12 January
Whitianga	6 November	14 December	17 November to 14 January
Kaipara Harbour entrance	30 October	7 December	31 October to 9 January

The crossing dates are the part that changes how you plan. Averaged over all 41 springs, the Motuihe Channel reaches 16 degrees around 1 November and 18 degrees around 2 December. Whangaparaoa is level at 16 and a day behind at 18. Great Barrier reaches 18 around 10 December, the Bay of Islands around 11 December, Whitianga around 14 December and the Kaipara entrance around 7 December. Those dates are later than most guides assume, including our own, which have tended to say the inner Gulf crosses 18 in early November. On the satellite record the shallow inner Gulf does reach 18 degrees first, but the seven day mean has not held 18 degrees before November in any of the 41 years, and the earliest was 1 November 2020 and the latest 10 January 2005, in the spring of 2004.

The Bay of Islands is the odd one out. It is often already close to 16 degrees by early September, so it rarely gets the full winter slowdown the inner Gulf does, but it reaches 18 later than the inner Gulf, probably because deep, well mixed water warms slowly.

Does a warm September mean an early season? More than we expected. Across the 41 springs at Motuihe the correlation between the water temperature on 11 September and the date the water later held 18 degrees is minus 0.6, and each degree of September warmth brings the 18 degree date forward by about 15 days on average. The relationship is loose, September explains only about a third of the year to year variation, but the direction is consistent. This year’s reading is 0.9 degrees above average, which on that relationship points to an inner Gulf crossing in the second half of November rather than early December.

That is also simply what the last decade looks like. In the first eleven springs of the record, 1985 to 1995, the Motuihe Channel reached 16 degrees around 7 November and 18 degrees around 9 December. In the last ten, 2016 to 2025, it reached them around 24 October and 17 November. The last five inner Gulf crossings of 18 degrees were 12 November in 2021, 4 November in 2022, 23 November in 2023, 14 November in 2024, 9 November in 2025.

The summer peak has moved too, from an average seven day high of 21.6 degrees in the first eleven years to 22.7 in the last ten, which is the change our twenty year Gulf temperature piece charted with a different dataset. The season now starts about three weeks earlier than it did when the record began, and this spring is starting on the warm side of that newer normal.

What the forecasters expect is a warm but jumpy spring. NIWA’s seasonal climate outlook for September to November, published on 2 September, says above average temperatures are most likely for the east and north of the North Island, and rainfall is most likely to be below normal there. It puts the 30 day coastal sea surface temperature anomaly to 30 August at 0.52 degrees above average for the north of the North Island and 0.42 above for the west, with the east of the North Island slightly below.

The catch is El Niño, which the outlook describes as already comparable to 1997 and likely to peak as one of the strongest in recent history. “El Niño is expected to influence spring weather patterns, favouring periods of active westerlies, unusually windy conditions, and greater temperature variability,” the outlook says, with the greatest risk of nationwide unsettled weather expected during mid to late spring. For anglers that means the water will probably cross 18 degrees on or a little before its usual date, and the problem will be finding a day calm enough to be on it.

The fish themselves are behaving oddly, at least close to the city. Bruce Duncan, who has fished the inner Gulf for decades and writes its report for The Fishing Website, opened his 3 September report by saying that he had seen many changes in the weather and movement of snapper in the Gulf, “but this year is something I have never seen before.” He wrote that “This winter so far has been incredibly frustrating for most,” that the fish were soft on the bite even with berley, and that the size mix had changed. “Again, different to years past is the size of the snapper; very few in the pannie size 34-38 cm, most in the 45-50 cm.” His advice was to fish one spot through the whole tide, prospect with casts at different angles, and put the effort into catching fresh bait.

Further out, George Bourke’s outer Gulf report the same day said, “Spring is starting to show its hand in the outer Hauraki Gulf, with some very encouraging pilchard workups developing and quality fish underneath them,” with the best of it well offshore around Cape Colville and Anchorite Rock and the bait only beginning to push in towards the closer islands.

Behind the daily reports the stock is in good shape. Fisheries New Zealand’s May 2026 stock assessment plenary says the Hauraki Gulf and Bay of Plenty snapper stock has been steadily increasing since the late 1990s, that fishing intensity has been below the overfishing threshold since 2021, and that it is very unlikely to fall below its limits at current catch levels. The East Northland stock rose from near its soft limit in 2010 to its target by 2023.

The snapper chapter’s introduction describes what happens next in the calendar. Large schools of snapper congregate before spawning and move on to the spawning grounds, usually in November and December, and in some areas and years the season runs on into March. Water temperature, it says, appears to play an important part in the success of recruitment, which is why a warm summer tends to show up as good fishing about five years later.

The recreational catch estimate in that report has halved. The plenary’s table of recreational catch estimates for SNA 1 shows the National Panel Survey estimate falling from about 2.6 million snapper and 3,127 tonnes in 2017-18 to about 1.3 million fish and 1,514 tonnes in 2022-23. For the Hauraki Gulf alone the estimate went from 1,684 tonnes to 629 tonnes. The survey is run every five or six years and the plenary treats it as broadly reliable rather than precise, so the halving is an indication rather than an exact count, but it is the official measure. The commercial catch limit for the whole of SNA 1 sits at 4,500 tonnes alongside a recreational allowance of 3,050. Whatever the cause, the recreational take measured in that survey was the lowest since the panel survey began in 2011-12, when the estimate was 3,981 tonnes.

The rules for the coming season are unchanged. The Ministry for Primary Industries rules for the Auckland and Kermadec area, last reviewed on 3 August 2026, set the east coast snapper limit at seven fish per person per day with a minimum length of 30 centimetres, inside a combined daily limit of 20 finfish. The west coast, including the Kaipara, allows 10 fish at 27 centimetres. The October 2026 sustainability round that Fisheries New Zealand consulted on in June and July, with submissions closed on 24 July, proposes changes to snapper in area two, the East Cape to Wellington stock, and to tarakihi, including recreational changes, ling, trevally and several South Island stocks. It does not touch SNA 1 or SNA 8, so the upper North Island snapper rules are not part of this year’s round.

So when do the snapper come in this year? Watch the tool. When the spot you fish holds 16 degrees for a week the fish will be feeding on the change of the tide, and our month by month Gulf guide covers the tactics for each stage from there. When it holds 18 the schools are gathering to spawn, and our spawning guide explains why the biggest fish of the year come in the fortnight either side. On the full 41 year record that second date falls in early December for the inner Gulf, in the last decade it has fallen in the second half of November, and this year the water is running ahead of both. We will publish the west coast picture for the Kaipara on 26 September, and a kingfish and gurnard piece on 3 October.

When does your first real snapper session of the spring usually happen, and what does the water read on the day? Tell us in the comments.

This article was written by AI, briefed to report the facts, hopefully without some of the bias people bring to the job 🙂