Greenly Garden

Last and first frost dates in Sapporo

Japan

In Sapporo the last spring frost usually comes around 9 May and the first autumn frost around 17 October, which leaves about 161 frost-free days (median of 2016–2025). Tomato seedlings can go into open ground from 30 June to 8 August.

Last spring frostaround 9 May
First autumn frostaround 17 October
Frost-free days161 days

Median of 2016–2025 for the 25 km grid cell of the city: the last day at or below 0 °C in spring and the first in autumn (ERA5 reanalysis via Open-Meteo). In a cold year a frost can come a week or two later — Greenly warns 48 hours ahead.

When is the last frost in Sapporo?

The last frost in Sapporo usually comes around 9 May: 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 18 April, while corn waits until 4 June. The first autumn frost follows around 17 October, about 161 days later: harvest or cover frost-tender crops before then.

When to sow and plant

CropSow for seedlingsPlant out in a greenhouseOpen ground
Achocha20 March – 9 July29 April – 18 August20 May – 18 August
Ageratumfrom 14 April—from 30 June
Arugula——sow 18 April – 12 September
Basil19 May – 15 August26 June – 22 September17 July – 22 September
Beet——sow 18 April – 18 August
Bell Pepper27 April – 9 June26 June – 8 August17 July – 8 August
Black-eyed Susanfrom 26 February—from 20 May
Bok Choy25 March – 26 August29 April – 30 September20 May – 30 September
Borage——sow 16 May – 23 August
Broad bean——sow 18 April – 9 July
Broccoli——sow 18 April – 2 July
Brussels Sprouts11 February – 30 May28 March – 14 July18 April – 14 July
Busy Lizziefrom 21 February—from 16 May
Cabbage——sow 18 April – 9 June
Calendula——sow from 18 April
Carrot——sow 18 April – 25 July
Cauliflower14 February – 2 July28 March – 13 August18 April – 13 August
Celeriac11 February – 29 April29 April – 15 July20 May – 15 July
Celery11 February – 9 May29 April – 25 July20 May – 25 July
Celosiafrom 30 Aprilfrom 14 Junefrom 5 July
Chamomile——sow 18 April – 13 August
Chayote15 February – 22 April14 May – 19 July4 June – 19 July
Chickpea——sow 18 April – 29 June
Chicory3 March – 24 July—18 April – 18 August
Chili Pepper27 April – 4 June26 June – 3 August17 July – 3 August
China asterfrom 5 Mayfrom 26 Junefrom 17 July
Chives——sow 18 April – 4 August
Cilantro——sow 18 April – 14 August
Corn——sow 4 June – 29 June
Corn poppy——sow from 18 April
Cosmosfrom 30 Aprilfrom 14 Junefrom 5 July
Cucumber29 May – 5 July26 June – 2 August17 July – 2 August
Daikon——sow 18 April – 11 August
Delphiniumfrom 28 January—from 18 April
Dill——sow 18 April – 24 August
Edging lobeliafrom 25 February—from 20 May
Eggplant27 April – 9 June26 June – 8 August17 July – 8 August
Florence fennel15 March – 9 July29 April – 23 August20 May – 23 August
Foxglovefrom 10 January—from 18 April
Garden sorrel——sow 18 April – 12 August
Green Beans——sow 5 July – 7 July
Hollyhock——sow from 18 April
Hyssop——sow 18 April – 5 July
Kale——sow 18 April – 6 August
Kiwano8 May – 12 July9 June – 13 August30 June – 13 August
Kohlrabi——sow 18 April – 16 August
Leek17 January – 20 April28 March – 29 June18 April – 29 June
Lemon balm——sow 18 April – 8 August
Lettuce——sow 18 April – 21 August
Lisianthusfrom 31 Decemberfrom 28 Marchfrom 18 April
Lovage——sow from 18 April
Luffafrom 15 Mayfrom 26 Junefrom 17 July
Marigoldfrom 18 Marchfrom 29 Aprilfrom 20 May
Marjoram27 April – 24 July—17 July – 22 September
Melon29 May – 22 June26 June – 20 July17 July – 20 July
Microgreens——sow 5 July – 3 October
Moringa8 May – 29 July2 July – 22 September23 July – 22 September
Moss rosefrom 28 February—from 16 May
Mustard greens——sow 18 April – 2 September
Napa cabbage27 March – 3 August29 April – 5 September20 May – 5 September
Nasturtiumfrom 22 Marchfrom 29 Aprilfrom 20 May
Okra15 May – 17 July26 June – 28 August17 July – 28 August
Oregano27 January – 14 July28 March – 12 September18 April – 12 September
Pansyfrom 31 Januaryfrom 28 Marchfrom 18 April
Parsley——sow 18 April – 2 August
Parsnip——sow 18 April – 21 June
Peanut20 May – 12 June26 June – 19 July17 July – 19 July
Peas——sow 18 April – 4 August
Petuniafrom 24 Aprilfrom 26 Junefrom 17 July
Physalis25 April – 9 June9 June – 24 July30 June – 24 July
Pumpkin15 May – 22 June26 June – 3 August17 July – 3 August
Purple coneflowerfrom 25 January—from 18 April
Radish——sow 18 April – 17 September
Sage7 February – 10 July28 March – 28 August18 April – 28 August
Scarlet sagefrom 18 April—from 30 June
Snapdragonfrom 22 Januaryfrom 28 Marchfrom 18 April
Soybean——sow 17 July – 29 July
Spinach——sow 18 April – 23 August
Stevia21 April – 31 May9 June – 19 July30 June – 19 July
Stock——sow from 18 April
Sunflower——sow from 5 July
Sweet alyssum——sow from 18 April
Sweet Corn29 April – 24 July21 May – 15 August11 June – 15 August
Sweet peafrom 14 Februaryfrom 28 Marchfrom 18 April
Sweet William——sow from 18 April
Swiss Chard——sow 18 April – 18 August
Thyme——sow 18 April – 29 June
Tomato18 April – 17 June9 June – 8 August30 June – 8 August
Turnip——sow 18 April – 20 August
Watercress——sow 18 April – 31 August
Watermelon29 May – 22 July26 June – 19 August17 July – 19 August
Zinniafrom 28 Mayfrom 2 Julyfrom 23 July
Zucchini5 June – 10 July26 June – 31 July17 July – 31 July

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 Sapporo

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 11 days after the last spring frost and 15 °C 52 days after it.

SoilDateAgainst the last spring frost
5 °C6 May3 days earlier
10 °C20 May11 days later
15 °C30 June52 days later
18 °C17 July69 days later

Frost dates near Sapporo

Of the nearest cities on our list, the last spring frost ends earliest in Niigata (8 March) and latest in Yuzhno-Sakhalinsk (9 May).

CityDistanceLast spring frostFirst autumn frost
Yuzhno-Sakhalinsk446 km9 May15 October
Sendai534 km31 March23 November
Niigata604 km8 March20 December
Vladivostok768 km8 April5 November
Khabarovsk774 km30 April16 October

Seeds, seedlings and markets in Sapporo

Within 15 km of Sapporo OpenStreetMap lists 2 garden centres, 1 farm-supply shop, 2 markets and 3 farm shops (collected 28 October 2026). The nearest market to the city centre is Nijo Market, 1 km away.

Places: © OpenStreetMap contributors, ODbL.

What to grow at home in winter in Sapporo

Frosts in Sapporo usually come from about 17 October to about 9 May. These plants have indoor care in their Greenly cards and are harvested quickly, so they can be sown on a windowsill in winter.

Weather in Sapporo by month

Average weather in Sapporo over 2016–2025: the warmest month is July. Months that average 20 °C or more by day: July (22.3 °C) and August (22.1 °C). Nights average below 0 °C in November–April (-11.9–-1.8 °C). About 1410 mm of rain falls in a year, on 192 days; August is the wettest month (200 mm) and February the driest (83 mm).

MonthDay, °CNight, °CRain, mmRainy days
January-6-11.910019
February-4.9-11.18318
March0.3-6.98915
April6.7-1.88713
May14.44.99313
June17.89.613316
July22.314.815116
August22.115.220017
September18.110.613913
October10.93.312014
November3.3-3.812117
December-4.1-10.59421

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

CropWhen to plant
Bearded Irisby 17 September
Crocus17 September – 31 October
Daffodil17 September – 31 October
Garlic17 September – 31 October
Grape hyacinthby 17 September
Helleboreby 17 September
Hyacinth17 September – 31 October
Lilyby 17 September
Ornamental onionby 17 September
Peonyby 17 September
Saffronby 17 September
Snowdropby 17 September
Tulip17 September – 31 October
Wild garlicby 17 September

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).