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Warmest sea in New Zealand in September

245 coastal locations in New Zealand ranked by their typical September sea temperature. Region-wide average in September: 13.7°C. The top of the list is where to find the warmest swimming this month.

Warmest in September

Fishing Rock

19.2°C September mean in New Zealand

Regional September average

13.7°C

across all 245 coastal locations in New Zealand

Vs annual mean

-2.6°C

below the year-round regional average

What the New Zealand sea feels like in September

Water at this temperature is cold and will feel very cold initially, but the body will get used to it and longer swims are possible. Experienced swimmers can manage several hours of swimming, however hypothermia is still a real risk.

New Zealand monthly average 13.6°C to 19.3°C
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  • Warmest month February 19.3°C
  • Coldest month August 13.6°C
  • Annual mean 16.3°C
  • Months above 20°C 0 of 12

Where September fits in the year

September sits inside the regional pattern shown on the left. Pick a different month to see how the ranking shifts.

All twelve New Zealand month rankings:

New Zealand sea temperature map (live)

The map shows today's latest reading at every New Zealand location. The list below is based on the typical September mean, useful for trip planning weeks or months ahead.

Zoom in to see individual locations. Click a pin for water temperatures. View list →
°C -2 0 1 3 5 7 9 11 13 15 17 19 21 24 27 30 35

Top 50 warmest New Zealand locations in September

Sorted by the typical September mean built from a decade of daily readings at each location. Click any place for its 30-day chart, monthly profile, and full 10-year history.

# Location September mean
1 Fishing Rock Sugar Loaf Islands 19.2°C
2 Coopers Beach 16.4°C
3 Bay of Islands 16.4°C
4 Waiiti Bay Northland 16.3°C
5 Kerikeri 16.3°C
6 Whangamumu Harbour Northland 16.3°C
7 North Cape (Otou) Northland 16.2°C
8 Paihia 16.2°C
9 Russell 16.2°C
10 Waitangi (Northland) 16.2°C
11 Waitangi 16.2°C
12 Whangaroa Northland 16.2°C
13 Doubtless Bay 16.2°C
14 Karikari Peninsula 16.2°C
15 Taipa 16.2°C
16 Doves Bay Northland 16.1°C
17 Mangonui 16.1°C
18 Opua Northland 16.1°C
19 Matapouri 16.0°C
20 Ngunguru 16.0°C
21 Tutukaka 16.0°C
22 Manawatāwhi/Great Island - North West Bay Area Outside Territorial Authority 16.0°C
23 Kotiatia Point Northland 15.9°C
24 Kaitaia 15.9°C
25 Bay of Plenty 15.8°C
Show 25 more ▸
26 Cape Reinga 15.8°C
27 Lottin Point Gisborne 15.6°C
28 Houhora Harbour Entrance Northland 15.6°C
29 Pukenui Wharf Northland 15.6°C
30 Whangarei 15.6°C
31 Cape Maria van Diemen Te Tai-tokerau 15.6°C
32 Burgess Island (Pokohinu) Auckland 15.6°C
33 Ngatehe Point Northland 15.5°C
34 Ahipara 15.5°C
35 Slipper Island (Whakahau) Waikato 15.4°C
36 Tapuaetahi Bay (Boat Harbour) Waikato 15.4°C
37 Pauanui 15.4°C
38 Tairua 15.4°C
39 Whangamata 15.4°C
40 Ahipara Bay Northland 15.4°C
41 Huruhi Harbour Waikato 15.3°C
42 Marsden Point Northland 15.3°C
43 Portland Wharf Northland 15.3°C
44 Cathedral Cove 15.3°C
45 Hahei 15.3°C
46 Hot Water Beach 15.3°C
47 Papamoa 15.3°C
48 Kohukohu Northland 15.3°C
49 Opononi Northland 15.3°C
50 Rawene Northland 15.3°C

Coldest 10 in New Zealand in September

Same data the other way. Helpful if you want to know which New Zealand coasts to avoid for swimming in September.

# Location September mean
1 Campbell Island/Motu Ihupuku - Perseverance Harbour New Zealand Outlying Islands 7.4°C
2 Auckland Island - Carnley Harbour Auckland 8.6°C
3 Dunedin 10.4°C
4 Portobello 10.4°C
5 Timaru 10.4°C
6 Sumner 10.5°C
7 Kaka Point 10.5°C
8 Akaroa 10.5°C
9 Christchurch 10.5°C
10 Lyttelton 10.5°C

More on this region