USDA Hardiness Zone 3b
Frost Dates for 56671 — Red Lake, Minnesota
Averages from Red Lake Indian Agcy, Mn US, the nearest reporting station, 5.9 miles away.
Plant tender crops after May 12, and expect the first autumn freeze around October 4. That leaves about 142 frost-free days.
- Last spring frost
- May 12
- First fall frost
- October 4
- Growing season
- 142 days
- Hardiness zone
- 3b
50% probability
50% probability
frost-free
-35 to -30°F annual low
Planting calendar for 56671
| When | What to do |
|---|---|
| March 3 – March 17 | Start peppers and aubergines indoors They need eight to ten weeks under lights before they can go out. |
| March 17 – March 31 | Start tomatoes indoors Six to eight weeks gives a transplant big enough to set fruit early. |
| April 14 – April 28 | Sow peas, spinach, lettuce, radish outdoors These tolerate light frost and prefer to germinate in cool soil. |
| May 12 onward | Transplant tomatoes, peppers, basil, squash, cucumbers The average last freeze has passed — still watch the actual forecast. |
| by July 12 | Sow the autumn crop of carrots, beets and brassicas They need about twelve weeks to size up before growth stops. |
| by September 20 | Harvest tender crops, or be ready to cover them A first freeze two weeks early is well within normal variation. |
| October 4 onward | Plant garlic, mulch beds, lift tender bulbs Garlic wants a cold spell; bare soil loses structure over winter. |
What these dates mean
Wait until after May 12 to put tender plants — tomatoes, peppers, basil, squash — in the ground. That is the date by which half of years in Red Lake, Minnesota are past their last freeze. Harvest before October 4, which leaves roughly 142 frost-free days.
ZIP 56671 sits in USDA hardiness zone 3b, meaning the average coldest night of the year falls between -35 to -30°F. Zone decides what survives the winter; frost dates decide when to plant each spring. They are different questions, and a plant can pass one and fail the other.
These are thirty-year NOAA averages for 1991–2020, not a forecast. Any individual year can frost two to three weeks either side of these dates, so check the actual forecast before planting out.