Frost Dates by NZ Region — A Practical Guide
Published June 27, 2026
Frost dates are the anchor of a NZ vegetable garden calendar. They tell you when it's safe to transplant frost-tender crops in spring, and when to expect the season to end in autumn. Getting this wrong — transplanting a week too early, or pushing summer crops too late into autumn — is the most common cause of crop losses that gardeners blame on pests or disease.
This guide gives practical frost date ranges for NZ's main growing regions, explains what the numbers mean for your garden, and tells you what to do with the information.
How Frost Dates Work
A "last spring frost" date is the average date after which frost is unlikely — not the absolute last possible frost. It's typically expressed as the date with a 50% or 90% probability of no further frosts. Gardening guides usually give you the 50% date.
What this means: If the last spring frost date for your area is October 15, there's roughly a 50% chance that frosts are over by then. A more cautious 90% probability date might be November 1.
For frost-tender crops (tomatoes, capsicums, courgettes, basil, cucumbers), most gardeners in frost-prone areas should work to the more conservative date, not the average. The risk of losing established transplants to a late frost is higher than the cost of waiting an extra two weeks.
NZ Frost Dates by Region
These are approximate average dates, based on NIWA climate data and regional gardening records. Microclimates vary significantly within regions — see notes below.
Northland and Auckland
| Location | Last spring frost | First autumn frost |
|---|---|---|
| Northland (most areas) | Effectively frost-free | Effectively frost-free |
| Auckland city / North Shore / Waitematā | Effectively frost-free | Effectively frost-free |
| South Auckland (Pukekohe, Waiuku) | Sept 15 | May 15 |
| Waiheke, Coromandel coast | Effectively frost-free | Effectively frost-free |
Notes: Most of Auckland and Northland is essentially frost-free. The exception is inland South Auckland (Pukekohe is notable as a vegetable-growing area with genuine frosts) and valley floors in the Waitākere and Hunua ranges. If you're in a valley in West Auckland, check your local conditions — they can differ significantly from general Auckland averages.
Waikato and Bay of Plenty
| Location | Last spring frost | First autumn frost |
|---|---|---|
| Hamilton | Oct 1 | May 1 |
| Tauranga | Effectively frost-free | Effectively frost-free |
| Rotorua | Oct 15 | Apr 15 |
| Taupō | Oct 20 – Nov 1 | Apr 1 – Apr 15 |
Notes: Hamilton has a frost history that surprises people given its latitude — it sits in a basin that collects cold air. Taupō, at altitude (357m), has noticeably earlier autumn frosts and later spring frosts than coastal Bay of Plenty.
Hawke's Bay and Gisborne
| Location | Last spring frost | First autumn frost |
|---|---|---|
| Napier / Hastings (flatland) | Sept 15 – Oct 1 | May 1 – May 15 |
| Inland Hawke's Bay (Central Hawke's Bay) | Oct 1 – Oct 15 | Apr 15 – May 1 |
| Gisborne | Sept 15 | May 1 |
Notes: Napier and Hastings have some of the best growing conditions in NZ — warm, dry, long season. Frosts are relatively light. Inland Central Hawke's Bay (Waipawa, Waipukurau) is cooler with more frost exposure.
Manawatū, Whanganui, and Taranaki
| Location | Last spring frost | First autumn frost |
|---|---|---|
| Palmerston North | Oct 1 – Oct 15 | Apr 15 – May 1 |
| Whanganui | Sept 15 – Oct 1 | May 1 |
| New Plymouth | Effectively frost-free to light frosts | Effectively frost-free to light frosts |
| Inland Manawatū (hill country) | Oct 15 – Nov 1 | Apr 1 – Apr 15 |
Notes: New Plymouth's coastal position makes it almost frost-free. Inland Manawatū hill country is meaningfully colder — treat it more like a cool/mountain zone than the coastal region.
Wellington and Wairarapa
| Location | Last spring frost | First autumn frost |
|---|---|---|
| Wellington city (coastal suburbs) | Effectively frost-free | Effectively frost-free |
| Wellington (inland/valley suburbs) | Oct 1 | May 1 |
| Wairarapa (Masterton, Carterton) | Oct 15 | Apr 15 |
| Martinborough | Oct 1 – Oct 15 | Apr 15 – May 1 |
Notes: Wellington's famously windy climate protects coastal suburbs from frost — wind prevents the still cold air that causes frost. Sheltered valley suburbs (Johnsonville, Ngaio, Brooklyn) get meaningful frosts. The Wairarapa, separated from the coast by the Remutaka Range, has genuine mid-continental frosts and a shorter effective season.
Nelson and Marlborough
| Location | Last spring frost | First autumn frost |
|---|---|---|
| Nelson city | Sept 15 – Oct 1 | May 1 – May 15 |
| Motueka | Sept 15 – Oct 1 | May 1 |
| Marlborough (Blenheim flatland) | Sept 15 – Oct 1 | May 1 |
| Marlborough high country | Oct 15 – Nov 1 | Apr 1 – Apr 15 |
Notes: Nelson and Blenheim enjoy long, warm, dry seasons — some of the best growing conditions in the South Island. The Marlborough high country (Rainbow Valley, Rai Valley) is significantly colder.
Canterbury
| Location | Last spring frost | First autumn frost |
|---|---|---|
| Christchurch city | Oct 1 – Oct 15 | Apr 15 – May 1 |
| Canterbury Plains (Selwyn, Waimakariri) | Oct 15 – Nov 1 | Apr 1 – Apr 15 |
| Inland Canterbury (Oxford, Darfield, Geraldine) | Oct 15 – Nov 1 | Apr 1 |
| Mackenzie Basin (Fairlie, Twizel, Tekapo) | Nov 1 – Nov 15 | Mar 15 – Apr 1 |
| Kaikōura coast | Oct 1 | May 1 |
Notes: Christchurch city is often confused with Canterbury's frost dates — the city itself is warmer and more protected than the surrounding plains. The Canterbury Plains have some of the most damaging frosts in NZ (cold, clear, still nights with high radiation frost risk). The Mackenzie Basin has an extremely compressed growing season.
Otago
| Location | Last spring frost | First autumn frost |
|---|---|---|
| Dunedin city | Oct 1 – Oct 15 | May 1 |
| Taieri Plain | Oct 15 – Nov 1 | Apr 15 |
| Central Otago (Alexandra, Cromwell, Clyde) | Oct 15 – Nov 1 | Apr 1 – Apr 15 |
| Queenstown / Wanaka | Nov 1 – Nov 15 | Mar 15 – Apr 1 |
| Maniototo (Ranfurly, Naseby) | Nov 1 – Nov 15 | Mar 15 |
Notes: Central Otago's continental climate delivers NZ's most extreme frosts — Alexandra regularly records the coldest temperatures in the country. Queenstown and Wanaka, despite their reputation, have meaningfully shorter effective growing seasons than many people expect. The Maniototo is one of NZ's harshest growing environments.
Southland
| Location | Last spring frost | First autumn frost |
|---|---|---|
| Invercargill | Oct 15 – Nov 1 | Apr 1 – Apr 15 |
| Gore | Oct 15 – Nov 1 | Apr 1 |
| Southland rural | Nov 1 – Nov 15 | Mar 15 – Apr 1 |
Notes: Southland's frosts are compounded by high rainfall and limited summer heat. Even in the frost-free window, cool daytime temperatures limit what warm-season crops can achieve without protection.
The Microclimate Caveat
Regional averages are a starting point, not a final answer. Your specific garden site can differ from the regional average by weeks in either direction due to:
- Valley floors and frost hollows — cold air drains downhill and pools in low areas. A frost hollow can experience frosts 3–4 weeks longer than a hillside 50 metres above it.
- North-facing slopes — receive more sun, warm faster in spring, and are often 2–3°C warmer than flat ground
- Urban heat — city gardens are often meaningfully warmer than the regional average, particularly overnight
- Proximity to water — coastal and lakeside sites have moderated temperatures
The only reliable way to know your microclimate is to observe it over several seasons. Keep records. A simple min/max thermometer in your garden is more useful than any regional frost table.
Using Frost Dates in Practice
For spring transplanting of frost-tender crops (tomatoes, capsicums, courgettes, basil): Add 2 weeks to your last spring frost date as a conservative transplant date. If your last frost date is October 15, plan to transplant no earlier than November 1. Use frost cloth for the first 2–3 weeks as insurance.
For timing indoor seed starting: Count back from your transplant date. Tomatoes need 6–8 weeks of indoor growing before transplant. If transplant date is November 1, start seeds by mid-September.
For autumn: Watch your first autumn frost date as the end point for frost-tender crops. Have frost cloth ready from 2 weeks before. Pick green tomatoes to ripen indoors when the first forecast frost arrives.
Frost dates are the foundation of the planting calendar. Find the full calendar for your zone →