Last and first frost dates in Windsor

When is the last frost in Windsor?

The last frost in Windsor usually comes around 24 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 3 April, while corn waits until 1 May. The first autumn frost follows around 7 November, about 197 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.

When the soil warms up in Windsor

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 20 days after it.

Frost dates near Windsor

Of the nearest cities on our list, the last spring frost ends earliest in Cleveland (9 April) and latest in Lansing (28 April).

Seeds, seedlings and markets in Windsor

Within 15 km of Windsor OpenStreetMap lists 3 garden centres, 1 farm-supply shop, 11 plant nurseries, 8 markets and 3 farm shops (collected 20 October 2026). The nearest garden centre to the city centre is Fairlane Gardens Landscape Supply, 15 km away.

• Fairlane Gardens Landscape Supply — garden centre
  Greenfield Road 4768, Dearborn · 15 km
• Key Foods — farm supply
  Russell Street 1352, 48207 Detroit · 6 km
• The Downtown Windsor Farmers Market — market
  Pelissier Street 505, N9A 4L2 Windsor · 2 km
• Oakland Avenue Farmers Market — farm shop
  Oakland Avenue 9354, 48211 Detroit · Sat 11:00–16:30 · 11 km
• Grand Food Liquor — market
  East Jefferson Avenue 7225, 48214 Detroit · 6 km
• Bert's Market Place — market
  Russell Street 2727-2739;2727, 48207 Detroit · 6 km

• Where to buy seeds and seedlings in Windsor
• Selling your own harvest in Canada

Places: © OpenStreetMap contributors, ODbL.

Weather in Windsor by month

Average weather in Windsor over 2016–2025: the warmest month is July. Months that average 20 °C or more by day: May–September (20.7–28.6 °C). Nights average below 0 °C in December–March (-5.9–-0.6 °C). About 942 mm of rain falls in a year, on 132 days; July is the wettest month (92 mm) and February the driest (60 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).