Last and first frost dates in Blenheim

When is the last frost in Blenheim?

The last frost in Blenheim usually comes around 10 August: that is the median of 2016–2025, so in about half of those years the last night at or below 0 °C came later. Hardy crops start before it and frost-tender ones only after it: in the table below arugula can go into open ground from 20 July, while corn waits until 20 September. The first autumn frost follows around 31 May, about 294 days later: harvest or cover frost-tender crops before then.

When to sow and plant

Planting out: a week after the last frost once the soil is warm enough for the crop; frost-hardy crops three weeks before it; an unheated greenhouse three weeks earlier. Seedlings are sown so they are ready on that day. 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.

When the soil warms up in Blenheim

The day the top 7 cm of soil first averages each temperature over a week, median of 2016–2025 (ERA5 via Open-Meteo). The soil reaches 10 °C 21 days after the last spring frost and 15 °C 81 days after it.

Frost dates near Blenheim

Of the nearest cities on our list, the last spring frost ends earliest in Nelson (4 August) and latest in Wellington (17 August).

Seeds, seedlings and markets in Blenheim

Within 15 km of Blenheim OpenStreetMap lists 1 market and 1 farm shop (collected 28 October 2026). The nearest market to the city centre is Marlborough Farmers' Market, 2 km away.

• Marlborough Farmers' Market — market
  Maxwell Road · Sun 09:00–12:00 · 2 km
• Golden Mile Produce — farm shop
  Sat 14:00–18:00 · 6 km

• Where to buy seeds and seedlings in Blenheim
• Selling your own harvest in New Zealand

Places: © OpenStreetMap contributors, ODbL.

Weather in Blenheim by month

Average weather in Blenheim over 2016–2025: the warmest month is January. Months that average 20 °C or more by day: December–March (21.1–23.3 °C). No month averages below 0 °C at night; the coldest nights, in July, average 5.3 °C. About 857 mm of rain falls in a year, on 110 days; July is the wettest month (92 mm) and January the driest (50 mm).

Average of the daily highs and lows, rain per month and days with at least 1 mm (ERA5 via Open-Meteo, the same grid cell as the frost dates).

Planted in autumn

From a month before the first autumn frost, so the roots grow before winter, to the late-planting limit on each crop’s page (about two weeks before the ground freezes, by ten years of weather).