Last and first frost dates in Invercargill

When is the last frost in Invercargill?

The last frost in Invercargill usually comes around 11 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 21 July, while corn waits until 17 October. The first autumn frost follows around 8 June, about 301 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 Invercargill

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 42 days after the last spring frost and 15 °C 109 days after it.

Frost dates near Invercargill

Of the nearest cities on our list, the last spring frost ends earliest in Nelson (4 August) and latest in Dunedin (26 October).

Weather in Invercargill by month

Average weather in Invercargill over 2016–2025: the warmest month is January. No month averages 20 °C by day; the warmest, January, reaches 18.4 °C. No month averages below 0 °C at night; the coldest nights, in July, average 5 °C. About 1303 mm of rain falls in a year, on 193 days; October is the wettest month (133 mm) and August the driest (82 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).