GreenlyGardening in New Zealand: climate, frost dates and crops by region
We worked out the season of 17 cities of New Zealand from ten years of weather: the frost-free season lasts from 208 days in Dunedin to 321 days in Nelson. The last spring frost comes first in Gisborne (around 4 July) and last in Dunedin (around 26 October). 3 of the cities had no frost at all.
Climate zones of New Zealand
By the days between the last spring frost and the first autumn frost.
| Zone | Cities | Frost-free days | Last spring frost | First autumn frost |
|---|---|---|---|---|
| 270 frost-free days or more | Hamilton (New Zealand), Palmerston North, Nelson, Blenheim, Christchurch, Invercargill | 294 – 321 | 4 August – 11 August | 31 May – 21 June |
| 210–269 frost-free days | Rotorua, Timaru, Queenstown | 218 – 258 | 10 September – 14 October | 20 May – 4 June |
| 150–209 frost-free days | Dunedin | 208 | 26 October | 22 May |
| Frost without a regular season | Tauranga, Gisborne, Napier, Wellington | — | 4 July – 18 August | — |
| No frost in ten years | Whangarei, Auckland, New Plymouth | — | — | — |
How the regions of New Zealand differ
Splitting the cities in two — north (Whangarei, Auckland, Tauranga and 5 more) and south (Nelson, Wellington, Blenheim and 5 more): the last spring frost comes about 8 days later in the south; the warmest month averages 23.8 °C by day in the north and 21.2 °C in the south; the north gets about 1,295 mm of rain a year and the south about 1,073 mm.
The gap between the warmest month’s days and the coldest month’s nights is widest in Queenstown (19.8 °C) and smallest in New Plymouth (9.4 °C): the smaller it is, the milder both winter and summer. Tauranga is the wettest of these cities with 1,769 mm a year, Christchurch the driest with 703 mm. The hottest summer days are in Hamilton (New Zealand) (24.8 °C on average in the warmest month), the coolest in Invercargill (18.4 °C). In none of these cities does a month average below 0 °C at night.
Which crops suit which part of New Zealand
Season long enough: the days from planting to the first autumn frost cover the days to the first harvest on the plant card. Each window starts on the Greenly calendar date and ends on the last day that still leaves the crop’s days to harvest (from its card) before the average first autumn frost, plus six weeks of picking for crops harvested over weeks (tomatoes, peppers, aubergines, cucumbers, courgettes, pumpkins, watermelons, beans) — our rule; earlier in the window is safer.
| Crop | Planting out or sowing | Season long enough | Tight or too short |
|---|---|---|---|
| Tomato | 26 October (Hamilton (New Zealand)) – 29 February (Palmerston North) | all 14 | — |
| Cucumber | 1 December (Christchurch) – 5 April (Palmerston North) | all 14 | — |
| Bell Pepper, Eggplant | 1 December (Christchurch) – 29 February (Palmerston North) | all 14 | — |
| Zucchini | 1 December (Christchurch) – 3 April (Palmerston North) | all 14 | — |
| Pumpkin | 1 December (Christchurch) – 24 February (Palmerston North) | all 14 | — |
| Watermelon | 1 December (Christchurch) – 11 March (Palmerston North) | all 14 | — |
| Peas | 14 July (Nelson) – 7 April (Palmerston North) | all 14 | — |
| Garlic | Autumn planting: 20 April (Queenstown) – end of June (Rotorua) | — | — |
| Tulip, Daffodil, Crocus, Hyacinth | Autumn planting: 20 April (Queenstown) – end of June (Queenstown) | — | — |
Cities without a spring frost: months that suit each crop
Months whose average day is not above the highest temperature on the plant card and whose average night is not below its lowest.
| City | Tomato | Cucumber | Bell Pepper | Eggplant | Watermelon |
|---|---|---|---|---|---|
| Whangarei | January, February | none | January, February | none | none |
| Auckland | January, February | none | December–March | none | none |
| New Plymouth | December–March | February | December–April | none | February |
Cities of New Zealand: weather in numbers
| City | Frost-free days | Warmest month, day | Coldest month, night | Rain a year | Driest month | Places to buy |
|---|---|---|---|---|---|---|
| Whangarei | no frost | February, 24 °C | August, 8.7 °C | 1,174 mm | March | 13 |
| Auckland | no frost | February, 23.6 °C | August, 9.2 °C | 1,292 mm | March | 33 |
| Tauranga | — | January, 23.5 °C | August, 6.7 °C | 1,769 mm | August | 6 |
| Hamilton (New Zealand) | 313 | February, 24.8 °C | August, 6.6 °C | 1,297 mm | March | 12 |
| Rotorua | 258 | February, 22.8 °C | August, 3.8 °C | 1,306 mm | January | 12 |
| Gisborne | — | January, 24.6 °C | July, 6.9 °C | 1,137 mm | May | 2 |
| New Plymouth | no frost | February, 20.6 °C | August, 11.2 °C | 1,726 mm | February | 2 |
| Napier | — | January, 24.3 °C | August, 7.1 °C | 1,002 mm | May | 7 |
| Palmerston North | 314 | February, 23.3 °C | August, 6.1 °C | 1,178 mm | January | 5 |
| Nelson | 321 | January, 22.8 °C | July, 5.5 °C | 1,252 mm | January | 5 |
| Wellington | — | January, 18.7 °C | July, 6.2 °C | 1,123 mm | January | 8 |
| Blenheim | 294 | January, 23.3 °C | July, 5.3 °C | 857 mm | January | 2 |
| Christchurch | 299 | February, 21.8 °C | July, 4.4 °C | 703 mm | August | 35 |
| Timaru | 255 | February, 21.4 °C | July, 2.4 °C | 829 mm | June | — |
| Queenstown | 218 | January, 21 °C | July, 1.2 °C | 1,488 mm | August | 2 |
| Dunedin | 208 | February, 18.9 °C | July, 2.3 °C | 1,022 mm | August | 3 |
| Invercargill | 301 | January, 18.4 °C | July, 5 °C | 1,303 mm | August | — |
ERA5 2016–2025 via Open-Meteo, 25 km grid cell of each city; dates by the Greenly calendar and the plant cards.
New Zealand by region: frost dates and planting windows
Each region’s page sets its cities side by side: frost dates, planting windows and weather by month.
