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Last and first frost dates in Grand Junction

United States

In Grand Junction the last spring frost usually comes around 18 April and the first autumn frost around 27 October, which leaves about 192 frost-free days (median of 2016–2025). Tomato seedlings can go into open ground from 25 April to 7 July.

Last spring frostaround 18 April
First autumn frostaround 27 October
Frost-free days192 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 Grand Junction?

The last frost in Grand Junction usually comes around 18 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 28 March, while corn waits until 25 April. The first autumn frost follows around 27 October, about 192 days later: harvest or cover frost-tender crops before then.

When to sow and plant

CropSow for seedlingsPlant out in a greenhouseOpen ground
Achocha23 February – 19 July4 April – 28 August25 April – 28 August
Ageratumfrom 7 February—from 25 April
Arugula——sow 28 March – 22 September
Basil8 March – 25 August15 April – 2 October6 May – 2 October
Beet——sow 28 March – 28 August
Bell Pepper14 February – 8 May15 April – 7 July6 May – 7 July
Black-eyed Susanfrom 1 February—from 25 April
Bok Choy28 February – 5 September4 April – 10 October25 April – 10 October
Borage——sow 25 April – 2 September
Broad bean——sow 28 March – 19 July
Broccoli——sow 28 March – 12 July
Brussels Sprouts21 January – 9 June7 March – 24 July28 March – 24 July
Busy Lizziefrom 31 January—from 25 April
Cabbage——sow 28 March – 19 June
Calendula——sow from 28 March
Carrot——sow 28 March – 4 August
Cauliflower24 January – 12 July7 March – 23 August28 March – 23 August
Celeriac17 January – 9 May4 April – 25 July25 April – 25 July
Celery17 January – 19 May4 April – 4 August25 April – 4 August
Celosiafrom 21 Februaryfrom 7 Aprilfrom 28 April
Chamomile——sow 28 March – 23 August
Chayote6 January – 2 May4 April – 29 July25 April – 29 July
Chickpea——sow 28 March – 9 July
Chicory10 February – 3 August—28 March – 28 August
Chili Pepper14 February – 14 June15 April – 13 August6 May – 13 August
China asterfrom 22 Februaryfrom 15 Aprilfrom 6 May
Chives——sow 28 March – 14 August
Cilantro——sow 28 March – 24 August
Corn——sow 25 April – 9 July
Corn poppy——sow from 28 March
Cosmosfrom 21 Februaryfrom 7 Aprilfrom 28 April
Cucumber18 March – 15 July15 April – 12 August6 May – 12 August
Daikon——sow 28 March – 21 August
Delphiniumfrom 7 January—from 28 March
Dill——sow 28 March – 3 September
Edging lobeliafrom 31 January—from 25 April
Eggplant14 February – 8 May15 April – 7 July6 May – 7 July
Florence fennel18 February – 19 July4 April – 2 September25 April – 2 September
Foxglovefrom 20 December—from 28 March
Garden sorrel——sow 28 March – 22 August
Green Beans——sow 28 April – 17 July
Hollyhock——sow from 28 March
Hyssop——sow 28 March – 15 July
Kale——sow 28 March – 16 August
Kiwano3 March – 22 July4 April – 23 August25 April – 23 August
Kohlrabi——sow 28 March – 26 August
Leek27 December – 30 April7 March – 9 July28 March – 9 July
Lemon balm——sow 28 March – 18 August
Lettuce——sow 28 March – 31 August
Lisianthusfrom 10 Decemberfrom 7 Marchfrom 28 March
Lovage——sow from 28 March
Luffa4 March – 16 May15 April – 27 June6 May – 27 June
Marigoldfrom 21 Februaryfrom 4 Aprilfrom 25 April
Marjoram14 February – 3 August—6 May – 2 October
Melon18 March – 2 July15 April – 30 July6 May – 30 July
Microgreens——sow 28 April – 13 October
Moringa26 February – 8 August22 April – 2 October13 May – 2 October
Moss rosefrom 7 February—from 25 April
Mustard greens——sow 28 March – 12 September
Napa cabbage2 March – 13 August4 April – 15 September25 April – 15 September
Nasturtiumfrom 25 Februaryfrom 4 Aprilfrom 25 April
Okra4 March – 27 July15 April – 7 September6 May – 7 September
Oregano6 January – 24 July7 March – 22 September28 March – 22 September
Pansyfrom 10 Januaryfrom 7 Marchfrom 28 March
Parsley——sow 28 March – 12 August
Parsnip——sow 28 March – 1 July
Peanut9 March – 22 June15 April – 29 July6 May – 29 July
Peas——sow 28 March – 14 August
Petuniafrom 11 Februaryfrom 15 Aprilfrom 6 May
Physalis18 February – 19 June4 April – 3 August25 April – 3 August
Pumpkin4 March – 21 May15 April – 2 July6 May – 2 July
Purple coneflowerfrom 4 January—from 28 March
Radish——sow 28 March – 27 September
Sage17 January – 20 July7 March – 7 September28 March – 7 September
Scarlet sagefrom 11 February—from 25 April
Snapdragonfrom 1 Januaryfrom 7 Marchfrom 28 March
Soybean——sow 6 May – 8 August
Spinach——sow 28 March – 2 September
Stevia14 February – 10 June4 April – 29 July25 April – 29 July
Stock——sow from 28 March
Sunflower——sow from 28 April
Sweet alyssum——sow from 28 March
Sweet Corn13 March – 3 August4 April – 25 August25 April – 25 August
Sweet peafrom 24 Januaryfrom 7 Marchfrom 28 March
Sweet William——sow from 28 March
Swiss Chard——sow 28 March – 28 August
Thyme——sow 28 March – 9 July
Tomato11 February – 16 May4 April – 7 July25 April – 7 July
Turnip——sow 28 March – 30 August
Watercress——sow 28 March – 10 September
Watermelon18 March – 20 June15 April – 18 July6 May – 18 July
Zinniafrom 18 Marchfrom 22 Aprilfrom 13 May
Zucchini25 March – 20 July15 April – 10 August6 May – 10 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 Grand Junction

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 10 days before the last spring frost and 15 °C 6 days after it.

SoilDateAgainst the last spring frost
5 °C12 March37 days earlier
10 °C8 April10 days earlier
15 °C24 April6 days later
18 °C6 May18 days later

Frost dates near Grand Junction

Of the nearest cities on our list, the last spring frost ends earliest in Provo (6 April) and latest in Colorado Springs (3 May).

CityDistanceLast spring frostFirst autumn frost
Provo293 km6 April7 November
Denver316 km1 May15 October
Colorado Springs326 km3 May15 October
Salt Lake City339 km24 April26 October
Fort Collins340 km25 April21 October

Seeds, seedlings and markets in Grand Junction

Within 15 km of Grand Junction OpenStreetMap lists 5 garden centres, 1 farm-supply shop, 1 market and 1 farm shop (collected 28 October 2026). The nearest garden centre to the city centre is Bookcliff Gardens, 3 km away.

Places: © OpenStreetMap contributors, ODbL.

What to grow at home in winter in Grand Junction

Frosts in Grand Junction usually come from about 27 October to about 18 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 Grand Junction by month

Average weather in Grand Junction over 2016–2025: the warmest month is July. Months that average 20 °C or more by day: May–September (25.4–35.1 °C). Months that average 30 °C or more by day: June (32.8 °C), July (35.1 °C) and August (33.3 °C). Nights average below 0 °C in January (-6.3 °C), February (-4.2 °C) and December (-4.3 °C). About 401 mm of rain falls in a year, on 73 days; March is the wettest month (57 mm) and June the driest (13 mm).

MonthDay, °CNight, °CRain, mmRainy days
January3-6.3357
February7-4.2408
March13.10.25711
April19.94.6357
May25.49.7306
June32.816.4133
July35.119.8152
August33.318.3245
September28.913.8285
October19.66.1547
November11.50.3366
December5-4.3346

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 27 September
Crocus27 September – 7 December
Daffodil27 September – 7 December
Garlic27 September – 7 December
Grape hyacinthby 27 September
Helleboreby 27 September
Hyacinth27 September – 7 December
Lilyby 27 September
Ornamental onionby 27 September
Peonyby 27 September
Saffronby 27 September
Snowdropby 27 September
Tulip27 September – 7 December
Wild garlicby 27 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).