Last and first frost dates in Green Bay

When is the last frost in Green Bay?

The last frost in Green Bay usually comes around 29 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 8 April, while corn waits until 10 May. The first autumn frost follows around 30 October, about 184 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 Green Bay?

The official USDA map (2023, 1991–2020 data) puts the centre of Green Bay (ZIP 54303) in zone 5b. Zone 5b stands for an average coldest night of -15 to -10 °F (-26.1 to -23.3 °C), so perennials hardy to zone 5b or a colder zone should come through a typical winter here.

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

When the soil warms up in Green Bay

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 5 days before the last spring frost and 15 °C 20 days after it.

Frost dates near Green Bay

Of the nearest cities on our list, the last spring frost ends earliest in Rockford (26 April) and latest in Traverse City (2 May).

Seeds, seedlings and markets in Green Bay

Within 15 km of Green Bay OpenStreetMap lists 6 garden centres, 1 plant nursery and 2 markets (collected 20 October 2026). The nearest market to the city centre is The Cannery Public Market, 0 km away.

• The Cannery Public Market — market
  North Broadway 320, 54303 Green Bay · 0 km
• Oneida Farmers Market — market
  Water Circle Place N7332, 54155 Oneida · Jun Thu[3]–Sept 30 Thu 12:00–18:00 · 14 km · oneida-nsn.gov

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

Places: © OpenStreetMap contributors, ODbL.

Weather in Green Bay by month

Average weather in Green Bay over 2016–2025: the warmest month is July. Months that average 20 °C or more by day: June–September (23–28 °C). Nights average below 0 °C in November–March (-9.8–-0.3 °C). About 870 mm of rain falls in a year, on 117 days; July is the wettest month (103 mm) and February the driest (37 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).