Last and first frost dates in Billings

When is the last frost in Billings?

The last frost in Billings usually comes around 25 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 4 April, while corn waits until 2 May. The first autumn frost follows around 14 October, about 172 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.

What planting zone is Billings?

The official USDA map (2023, 1991–2020 data) puts the centre of Billings (ZIP 59101) in zone 5a. Zone 5a stands for an average coldest night of -20 to -15 °F (-28.9 to -26.1 °C), so perennials hardy to zone 5a or a colder zone should come through a typical winter here.

Check the official USDA map for Billings: USDA Plant Hardiness Zone Map.

When the soil warms up in Billings

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 6 days before the last spring frost and 15 °C 16 days after it.

Frost dates near Billings

Of the nearest cities on our list, the last spring frost ends earliest in Rapid City (7 May) and latest in Casper (26 May).

Seeds, seedlings and markets in Billings

Within 15 km of Billings OpenStreetMap lists 7 garden centres, 11 farm-supply shops, 3 plant nurseries and 4 markets (collected 20 October 2026). The nearest garden centre to the city centre is Roots Garden Center, 6 km away.

• Roots Garden Center — garden centre
  Poly Drive 2147, Billings · Mon–Sun 09:00–17:00 · 6 km
• Walmart Garden Center — garden centre
  King Avenue West 2525, 59102 Billings · Mon–Sun 06:00–23:00 · 7 km · walmart.com

• Where to buy seeds and seedlings in Billings
• Selling your own harvest in the United States

Places: © OpenStreetMap contributors, ODbL.

Weather in Billings by month

Average weather in Billings over 2016–2025: the warmest month is July. Months that average 20 °C or more by day: May–September (20.3–31.9 °C). Months that average 30 °C or more by day: July (31.9 °C) and August (31 °C). Nights average below 0 °C in November–March (-9.8–-1.6 °C). About 460 mm of rain falls in a year, on 84 days; May is the wettest month (76 mm) and July the driest (18 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).