Greenly Garden

Last and first frost dates in Olomouc

Czechia

In Olomouc the last spring frost usually comes around 21 April and the first autumn frost around 6 November, which leaves about 199 frost-free days (median of 2016–2025). Tomato seedlings can go into open ground from 17 May to 17 July.

Last spring frostaround 21 April
First autumn frostaround 6 November
Frost-free days199 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 Olomouc?

The last frost in Olomouc usually comes around 21 April: 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 31 March, while corn waits until 28 April. The first autumn frost follows around 6 November, about 199 days later: harvest or cover frost-tender crops before then.

When to sow and plant

CropSow for seedlingsPlant out in a greenhouseOpen ground
Achocha26 February – 29 July7 April – 7 September28 April – 7 September
Ageratumfrom 1 March—from 17 May
Arugula——sow 31 March – 2 October
Basil5 April – 4 September13 May – 12 October3 June – 12 October
Beet——sow 31 March – 7 September
Bell Pepper14 March – 18 May13 May – 17 July3 June – 17 July
Black-eyed Susanfrom 4 February—from 28 April
Bok Choy3 March – 15 September7 April – 20 October28 April – 20 October
Borage——sow 28 April – 12 September
Broad bean——sow 31 March – 29 July
Broccoli——sow 31 March – 22 July
Brussels Sprouts24 January – 19 June10 March – 3 August31 March – 3 August
Busy Lizziefrom 3 February—from 28 April
Cabbage——sow 31 March – 29 June
Calendula——sow from 31 March
Carrot——sow 31 March – 14 August
Cauliflower27 January – 22 July10 March – 2 September31 March – 2 September
Celeriac20 January – 19 May7 April – 4 August28 April – 4 August
Celery20 January – 29 May7 April – 14 August28 April – 14 August
Celosiafrom 18 Marchfrom 2 Mayfrom 23 May
Chamomile——sow 31 March – 2 September
Chayote9 January – 12 May7 April – 8 August28 April – 8 August
Chickpea——sow 31 March – 19 July
Chicory13 February – 13 August—31 March – 7 September
Chili Pepper14 March – 24 June13 May – 23 August3 June – 23 August
China asterfrom 22 Marchfrom 13 Mayfrom 3 June
Chives——sow 31 March – 24 August
Cilantro——sow 31 March – 3 September
Corn——sow 28 April – 19 July
Corn poppy——sow from 31 March
Cosmosfrom 18 Marchfrom 2 Mayfrom 23 May
Cucumber15 April – 25 July13 May – 22 August3 June – 22 August
Daikon——sow 31 March – 31 August
Delphiniumfrom 10 January—from 31 March
Dill——sow 31 March – 13 September
Edging lobeliafrom 3 February—from 28 April
Eggplant14 March – 18 May13 May – 17 July3 June – 17 July
Florence fennel21 February – 29 July7 April – 12 September28 April – 12 September
Foxglovefrom 23 December—from 31 March
Garden sorrel——sow 31 March – 1 September
Green Beans——sow 23 May – 27 July
Hollyhock——sow from 31 March
Hyssop——sow 31 March – 25 July
Kale——sow 31 March – 26 August
Kiwano25 March – 1 August26 April – 2 September17 May – 2 September
Kohlrabi——sow 31 March – 5 September
Leek30 December – 10 May10 March – 19 July31 March – 19 July
Lemon balm——sow 31 March – 28 August
Lettuce——sow 31 March – 10 September
Lisianthusfrom 13 Decemberfrom 10 Marchfrom 31 March
Lovage——sow from 31 March
Luffa1 April – 26 May13 May – 7 July3 June – 7 July
Marigoldfrom 24 Februaryfrom 7 Aprilfrom 28 April
Marjoram14 March – 13 August—3 June – 12 October
Melon15 April – 12 July13 May – 9 August3 June – 9 August
Microgreens——sow 23 May – 23 October
Moringa7 April – 18 August1 June – 12 October22 June – 12 October
Moss rosefrom 10 February—from 28 April
Mustard greens——sow 31 March – 22 September
Napa cabbage5 March – 23 August7 April – 25 September28 April – 25 September
Nasturtiumfrom 28 Februaryfrom 7 Aprilfrom 28 April
Okra1 April – 6 August13 May – 17 September3 June – 17 September
Oregano9 January – 3 August10 March – 2 October31 March – 2 October
Pansyfrom 13 Januaryfrom 10 Marchfrom 31 March
Parsley——sow 31 March – 22 August
Parsnip——sow 31 March – 11 July
Peanut6 April – 2 July13 May – 8 August3 June – 8 August
Peas——sow 31 March – 24 August
Petuniafrom 11 Marchfrom 13 Mayfrom 3 June
Physalis12 March – 29 June26 April – 13 August17 May – 13 August
Pumpkin1 April – 31 May13 May – 12 July3 June – 12 July
Purple coneflowerfrom 7 January—from 31 March
Radish——sow 31 March – 7 October
Sage20 January – 30 July10 March – 17 September31 March – 17 September
Scarlet sagefrom 5 March—from 17 May
Snapdragonfrom 4 Januaryfrom 10 Marchfrom 31 March
Soybean——sow 3 June – 18 August
Spinach——sow 31 March – 12 September
Stevia8 March – 20 June26 April – 8 August17 May – 8 August
Stock——sow from 31 March
Sunflower——sow from 23 May
Sweet alyssum——sow from 31 March
Sweet Corn21 March – 13 August12 April – 4 September3 May – 4 September
Sweet peafrom 27 Januaryfrom 10 Marchfrom 31 March
Sweet William——sow from 31 March
Swiss Chard——sow 31 March – 7 September
Thyme——sow 31 March – 19 July
Tomato5 March – 26 May26 April – 17 July17 May – 17 July
Turnip——sow 31 March – 9 September
Watercress——sow 31 March – 20 September
Watermelon15 April – 30 June13 May – 28 July3 June – 28 July
Zinniafrom 27 Aprilfrom 1 Junefrom 22 June
Zucchini22 April – 30 July13 May – 20 August3 June – 20 August

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 Olomouc

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 7 days before the last spring frost and 15 °C 26 days after it.

SoilDateAgainst the last spring frost
5 °C5 March47 days earlier
10 °C14 April7 days earlier
15 °C17 May26 days later
18 °C3 June43 days later

Frost dates near Olomouc

Of the nearest cities on our list, the last spring frost ends earliest in Opava (18 April) and latest in Brno (24 April).

CityDistanceLast spring frostFirst autumn frost
Zlín51 km19 April6 November
Opava61 km18 April4 November
Brno63 km24 April6 November
Ostrava77 km19 April9 November
Frýdek-Místek80 km19 April9 November

Seeds, seedlings and markets in Olomouc

Within 15 km of Olomouc OpenStreetMap lists 5 garden centres, 1 farm-supply shop, 1 plant nursery and 1 market (collected 28 October 2026). The nearest garden centre to the city centre is Okrasná školka Droždín, 7 km away.

Places: © OpenStreetMap contributors, ODbL.

What to grow at home in winter in Olomouc

Frosts in Olomouc usually come from about 6 November to about 21 April. 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 Olomouc by month

Average weather in Olomouc over 2016–2025: the warmest month is August. Months that average 20 °C or more by day: June–September (21.2–26.3 °C). Nights average below 0 °C in January (-2.9 °C), February (-1.5 °C) and December (-1 °C). About 726 mm of rain falls in a year, on 122 days; September is the wettest month (93 mm) and January the driest (38 mm).

MonthDay, °CNight, °CRain, mmRainy days
January3.1-2.9389
February6.2-1.5419
March10.50.4399
April15.14.4459
May19.38.87113
June2513.98012
July26.115.27612
August26.315.38510
September21.211.29310
October156.66010
November8.21.9539
December4.1-14510

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 7 October
Crocus7 October – end of December
Daffodil7 October – end of December
Garlic7 October – end of December
Grape hyacinthby 7 October
Helleboreby 7 October
Hyacinth7 October – end of December
Lilyby 7 October
Ornamental onionby 7 October
Peonyby 7 October
Saffronby 7 October
Snowdropby 7 October
Tulip7 October – end of December
Wild garlicby 7 October

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).