First Frost Date Windsor — October 28 (Zone 7a)
First frost date Windsor: October 28 for the city average (Zone 7a) — Canada’s warmest inland city. The riverfront, Lake Erie shore, and Pelee Island hold out longest; the rural Essex interior frosts about a week earlier. Harvest deadlines, area breakdown, season extension.
Updated June 2026 · Environment and Climate Change Canada normals (1991–2020)
First frost date Windsor 2026: October 28 for the city average (Zone 7a) — Canada’s warmest inland city. The Detroit River riverfront, Lake Erie shore, and Pelee Island hold out latest, into mid-November; the rural interior of Essex County frosts about a week earlier. Harvest tomatoes, peppers, and basil before mid-October frost watches begin; kale, carrots, and Brussels sprouts improve after frost and can stay in. Source: Environment and Climate Change Canada climate normals (1991–2020).
Mid-season maintenance in Windsor
- Succession sow lettuce, bush beans, and radishes every 2–3 weeks for continuous harvest.
- Water deeply (2.5 cm/week) at the base of plants — mulch helps retain moisture.
- Stake tomatoes and watch for early blight on the lower leaves; remove affected foliage promptly.
Come back next week: Around July 30 it's time to sow fall crops (kale, spinach, cilantro) for autumn harvest.
🍂 Windsor Frost Dates at a Glance
Historical Average and Range
The first frost date for Windsor — October 28 — is the 50th-percentile historical average from Environment and Climate Change Canada climate normals (1991–2020). Half of recent autumns stayed frost-free past October 28, half frosted before. The range runs from about October 14 (earliest, in the rural interior) to November 12 (latest, on the lake and river shores).
Windsor is wrapped by water — Lake Erie to the south, Lake St. Clair to the north, and the Detroit River between — which makes it Canada’s warmest inland city and gives it a Zone 7a climate found nowhere else away from the coasts. The lakeshore strip and Pelee Island, Canada’s southernmost point, hold out longest; the rural interior of Essex County, a step removed from the water, frosts about a week earlier.
Windsor’s growing season is the longest of any inland Canadian city, and the gap between the first light frost and the first hard freeze (−4°C or colder) usually stretches into mid-to-late November. That long, warm tail makes the area Canada’s best for long-season heat-loving crops, and keeps tomatoes, peppers, and hardy greens producing deep into the fall.
First Frost Across Windsor and Essex County
Proximity to Lake Erie, Lake St. Clair, and the Detroit River sets the date. The shorelines hold out longest; the rural interior of Essex County frosts first as cold air drains across open farmland on clear nights.
| Area / Community | Avg. First Frost | Zone | Notes |
|---|---|---|---|
| Pelee Island | Oct 30–Nov 12 | 7b | Surrounded by Lake Erie; warmest, latest |
| Leamington, Kingsville (Lake Erie shore) | Oct 28–Nov 8 | 7a | Lake-moderated; greenhouse belt |
| Downtown, Detroit River, Walkerville | Oct 28–Nov 6 | 7a | River-moderated core |
| Riverside, east riverfront | Oct 26–Nov 3 | 7a | River shoreline; mild |
| Tecumseh, Lakeshore, Forest Glade | Oct 24–30 | 6b/7a | Lake St. Clair shore; mild |
| LaSalle, South Windsor | Oct 22–28 | 7a | Slightly inland; mixed |
| Amherstburg | Oct 24–30 | 7a | Detroit River mouth; moderated |
| Rural interior Essex County | Oct 14–22 | 6b | Open farmland radiates fast; earliest |
Dates derived from ECCC climate normals (1991–2020) and station-level observations from Windsor Airport (YQG, inland and cooler than the shorelines). Treat as historical averages; shoreline vs interior timing varies year to year.
What to Harvest Before Windsor's First Frost — and What to Leave In
The October 28 first frost splits the Windsor garden into two lists. Tender crops are finished by the first frost of any intensity — wrap up that harvest as frost watches begin in mid-October inland. Hardy crops shrug off light frost and improve with it, and Windsor’s long, warm fall keeps them producing well into November.
⚠️ Harvest before first frost
- Tomatoes: pick all fruit, even green — ripen indoors at 18–21°C
- Basil: before nights hit 5°C — cold damages it pre-frost
- Peppers, eggplant: killed by the lightest frost
- Cucumbers, zucchini, beans: final picking on a frost forecast
- Winter squash, pumpkins: cut with 5–8 cm stem, cure 10 days warm
- Potatoes: dig after tops die back, before a hard freeze
❄️ Leave in — improves after frost
- Kale, Brussels sprouts: sweeter after 2–3 frosts
- Carrots, parsnips: mulch heavily and dig until the ground freezes
- Leeks, cabbage: stand through repeated light frosts
- Spinach, arugula: keep producing under row cover
- Swiss chard: survives to about −4°C uncovered
- Garlic: plant it now — mid-to-late October, before the ground freezes
How to Extend the Season Past Windsor's First Frost
Windsor’s first frost is usually one or two clear, calm nights followed by milder weather, and the area’s warmth gives season extension a long runway. Protecting tender crops through those first nights is the highest-return move.
Row cover on frost-watch nights
Spun-bonded fabric (Reemay, Agribon) draped over tomatoes, peppers, and greens before sunset traps ground heat and protects to about −3°C — more than the typical first frost delivers. Cover for the first 2–3 cold nights and the harvest usually continues for weeks. Weight the edges; remove once morning temperatures clear 5°C.
Exploit Canada’s warmest inland microclimate
Windsor’s wrap of warm water gives it the longest runway for season extension of any inland Canadian city. Shoreline and riverfront gardens routinely run two weeks longer than the rural interior; with row cover on the first frost nights, lakeshore tomatoes ripen into November. If you garden in open Essex farmland you frost a week earlier and should act sooner — the warmest spot on any property is against the house, not the open field edge.
Cold frames and low tunnels for fall greens
A cold frame or low tunnel keeps spinach, lettuce, mâche, and Asian greens producing well past first frost in most Windsor years. Sow hardy greens in mid-to-late August so plants reach full size before the light fades; overwintered spinach under cover restarts in spring weeks ahead of anything direct-sown.
Know when to stop
The real season-ender is the first hard freeze (−4°C or colder) plus fading daylight — below about 10 hours, growth stops regardless of temperature. Harvest what is mature, tuck covered greens in for winter picking, and switch energy to planting garlic and spring bulbs.
A lightweight floating row cover you drape over beds on the first clear frost nights — in Canada’s warmest inland city it routinely adds weeks of harvest at the fall end of the season.
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How Windsor's First Frost Compares to Other Canadian Cities
Windsor’s October 28 first frost is among the latest in Canada — Canada’s warmest inland city, behind only the BC coast.
| City | First Frost | Zone | Season | vs. Windsor |
|---|---|---|---|---|
| Victoria | Dec 15 | 8b | ~280 days | 48 days later |
| Vancouver | Nov 30 | 8b | ~260 days | 33 days later |
| Toronto | Nov 1 | 6b | ~197 days | 4 days later |
| Windsor | Oct 28 | 7a | ~191 days | — |
| Halifax | Oct 18 | 6a | ~161 days | 10 days earlier |
| Ottawa | Oct 12 | 5a | ~155 days | 16 days earlier |
| Montreal | Oct 7 | 5b | ~150 days | 21 days earlier |
| Edmonton | Sept 23 | 4a | ~132 days | 35 days earlier |
| Calgary | Sept 21 | 3b | ~120 days | 37 days earlier |
| Saskatoon | Sept 12 | 3b | ~110 days | 46 days earlier |
Common Questions about Windsor's First Frost
When should I pick my green tomatoes in Windsor?
When the forecast shows an overnight low of 4°C or below under clear skies — mid-October in the rural interior, late October to early November on the lake and river shores. Pick everything showing colour plus full-size green fruit and ripen indoors, or cover the plants through the first frost nights; Windsor’s long, warm fall often rewards covering with several more weeks of on-vine ripening.
Why is Windsor warmer in fall than the rest of inland Canada?
Water and latitude. Windsor is Canada’s southernmost mainland city, wrapped by Lake Erie, Lake St. Clair, and the Detroit River. All that water holds summer heat far into the fall and lifts overnight lows, giving Windsor a Zone 7a climate found nowhere else inland. Pelee Island, fully surrounded by Lake Erie, is warmer still. Only the rural interior of Essex County, a step removed from the water, frosts on a more typical inland schedule.
When should I plant garlic in Windsor?
Mid-to-late October — roughly 2–3 weeks before the ground freezes solid, which gives cloves time to root without sprouting above ground. The first frost is a useful planting signal. Hardneck varieties (Music, Russian Red) overwinter reliably under 10 cm of straw or shredded-leaf mulch. See the when to plant garlic guide for depth and spacing.
When is Windsor's last spring frost?
April 20 for the riverfront and Lake Erie shore. Together with the October 28 first fall frost, Windsor gets roughly 191 frost-free days. The full spring breakdown — area dates, microclimate, what to plant when — is on the Last Frost Date Windsor page.
Where does this frost date data come from?
Environment and Climate Change Canada (ECCC) climate normals for the 1991–2020 reference period, supplemented by station-level observations from Windsor Airport (YQG). The October 28 average reflects the primary urban station; area dates are adjusted for elevation, water proximity, and cold-air drainage.
📍 Related Windsor Garden Guides
Plan the Whole Windsor Season
The Windsor planting guide turns the April 20 – October 28 frost-free window into a month-by-month schedule for 25+ vegetables — including the long-season heat-lovers Windsor grows better than anywhere inland in Canada.