Greenly Garden

When to plant bell peppers in Thunder Bay: 8 July – 14 August

In Thunder Bay, bell pepper: sow for seedlings from 18 April to 15 June; plant into a greenhouse from 17 June to 14 August; plant out into open ground from 8 July to 14 August.

Bell Pepper in Thunder Bay: soil, season and weather

In Thunder Bay the soil, not frost, sets the date: the last frost is over around 11 May, but the top 7 cm of soil reaches 18 °C — the minimum on the bell pepper card — only around 8 July, 58 days later. 107 days separate planting out (8 July) from the first autumn frost (23 October); the card's 70 days to the first harvest leave 37 for picking, so a start 5 weeks late would still fit.

Last spring frost11 May
Top 7 cm of soil at 18 °C8 July, 58 days after the last frost
Into an unheated greenhouse17 June – 14 August; June outside: 10.4 °C at night, 19.9 °C by day; card 15–30 °C
First autumn frost23 October, 107 days after the start
Days in the bed to the first harvest (card)70
First harvest, if planted in this window16 September – 23 October
Days left for picking37
Daylight14:55 on 9 May, 15:55 on 8 July
Watering outdoors when fruiting (card)every 4 days; the driest month, August, has 11 rainy days

The same dates in Thunder Bay hold for Cucumber, Eggplant, Zucchini, Pumpkin and Watermelon.

Bell Pepper in Thunder Bay: care after planting

Planted on 8 July: in the first weeks water every 5 days.

Feeding, by the card’s schedule from that day:

  • 8 July — feed: balanced (NPK)
  • 5 August — feed: nitrogen

Pests and diseases of bell pepper to watch for:

Dates count from the first planting day of the window above; a later planting moves them by as many days.

Weather in Thunder Bay during the bell pepper season

No month of the season averages above the bell pepper card's 15–30 °C by day; the warmest, July, averages 23.6 °C. Months that stay below 15 °C even by day on average: October (10.5 °C). Nights average below 15 °C in every month of the season, from 4.2 °C to 14.4 °C.

MonthDay, °CNight, °CRain, mmRainy daysDaylight on the 15th
July23.614.4741115:44
August22.314.2631114:23
September18.210.9861112:38
October10.54.2711010:54

ERA5 2016–2025, Open-Meteo

Bell Pepper in nearby cities

All the nearest cities on our list plant bell pepper earlier than Thunder Bay; the closest date is in Duluth, 10 days earlier.

CityDistanceDateDifference
Duluth279 km28 June – 8 July10 days earlier
Green Bay439 km27 May – 10 July42 days earlier
Minneapolis487 km28 May – 4 July41 days earlier
Traverse City488 km5 June – 20 July33 days earlier
Grand Forks584 km5 June – 26 June33 days earlier
Fargo589 km31 May – 26 June38 days earlier

Where to buy bell pepper plants and seeds near Thunder Bay

Buy plants ready to set out from 8 July to 14 August (from 17 June to 14 August for an unheated greenhouse); seed for raising your own is sown from 18 April to 15 June. Within 15 km of Thunder Bay OpenStreetMap lists 2 garden centres and 1 market (collected 20 October 2026).

Places: © OpenStreetMap contributors, ODbL.

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.

Questions

When to plant bell peppers in Thunder Bay?

In Thunder Bay, bell pepper: sow for seedlings from 18 April to 15 June; plant into a greenhouse from 17 June to 14 August; plant out into open ground from 8 July to 14 August.

When to sow bell peppers for seedlings in Thunder Bay?

Sow for seedlings from 18 April to 15 June.

When is the last spring frost in Thunder Bay?

Last spring frost around 11 May, first autumn frost around 23 October.

Other crops in Thunder Bay, with their dates