Frost dates for 55811 — Duluth, MN
Last spring frostMay 13median date
First fall frostOct 1median date
Growing season141 daysfrost-free
Hardiness zone4bZone 4b
How Duluth compares
- In 8 years out of 10, the last spring frost in Duluth falls between April 29 and May 29, a 30-day window. The first fall frost falls between September 18 and October 16.
- The median last frost is 8 days later than the Minnesota median of May 5.
- Its 141-day growing season is longer than 22% of the 801 Minnesota places with a regular frost season (state median 151 days).
- The last frost is 5 days later than the zone 4b median of May 8. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 4b chart.
- The weather station records an average of 177 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 29 |
| 50% (median) | May 13 |
| 10% (safe for tender plants) | May 29 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 18 |
| 50% (median) | October 1 |
| 90% (late) | October 16 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Duluth, MN
Frost dates for 55811 — Duluth, MN — last frost May 13, first frost Oct 1, zone 4b. whenisthelastfrost.com
Crop
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Start indoors: Feb 18 to Mar 4Transplant outside: Apr 15 to Apr 29
Start indoors: Mar 4 to Mar 18Transplant outside: May 27 to Jun 10
Start indoors: Mar 4 to Mar 18Transplant outside: May 27 to Jun 10
Start indoors: Mar 18 to Apr 1Transplant outside: May 20 to Jun 3
Start indoors: Mar 18 to Apr 1Transplant outside: Apr 22 to May 6Sow outdoors: Apr 15 to May 20Plant for fall: Aug 6 to Sep 3
Start indoors: Mar 18 to Apr 1Transplant outside: Apr 15 to Apr 29Sow outdoors: Apr 15 to Apr 29Plant for fall: Jul 23 to Aug 13
Start indoors: Mar 18 to Apr 1Transplant outside: Apr 29 to May 13Plant for fall: Jun 25 to Jul 16
Start indoors: Mar 18 to Apr 1Transplant outside: Apr 22 to May 6Plant for fall: Jun 25 to Jul 16
Start indoors: Mar 18 to Apr 1Transplant outside: Apr 29 to May 13Plant for fall: Jun 25 to Jul 16
Start indoors: Apr 1 to Apr 15Transplant outside: Jun 3 to Jun 17Sow outdoors: Jun 3 to Jun 17
Start indoors: Apr 1 to Apr 15Transplant outside: May 20 to Jun 3
Sow outdoors: Apr 1 to Apr 22Plant for fall: Jul 9 to Jul 30
Sow outdoors: Apr 1 to Apr 22Plant for fall: Aug 6 to Aug 27
Sow outdoors: Apr 8 to May 20Plant for fall: Aug 20 to Sep 10
Start indoors: Apr 15 to Apr 22Transplant outside: May 27 to Jun 3Sow outdoors: May 20 to Jun 3Plant for fall: Jul 16 to Jul 30
Start indoors: Apr 15 to Apr 22Sow outdoors: May 20 to Jun 3Plant for fall: Jul 23 to Aug 6
Start indoors: Apr 15 to Apr 22Sow outdoors: May 20 to Jun 3
Start indoors: Apr 15 to Apr 22Transplant outside: May 27 to Jun 10
Sow outdoors: Apr 22 to May 20Plant for fall: Jul 9 to Jul 23
Sow outdoors: Apr 22 to May 20Plant for fall: Jul 23 to Aug 6
Sow outdoors: Apr 22 to May 13
Sow outdoors: Apr 29 to May 27Plant for fall: Jul 23 to Aug 6
Sow outdoors: Apr 29 to May 20Plant for fall: Aug 6 to Aug 27
Sow outdoors: May 20 to Jun 10Plant for fall: Jul 16 to Jul 30
Sow outdoors: May 20 to Jun 3
Transplant outside: May 27 to Jun 17
Plant for fall: Sep 17 to Oct 22
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Duluth, MN
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 18 – Mar 4 | Apr 15 – Apr 29 | — | — |
| Peppers | Mar 4 – Mar 18 | May 27 – Jun 10 | — | — |
| Eggplant | Mar 4 – Mar 18 | May 27 – Jun 10 | — | — |
| Tomatoes | Mar 18 – Apr 1 | May 20 – Jun 3 | — | — |
| Lettuce | Mar 18 – Apr 1 | Apr 22 – May 6 | Apr 15 – May 20 | Aug 6 – Sep 3 |
| Kale | Mar 18 – Apr 1 | Apr 15 – Apr 29 | Apr 15 – Apr 29 | Jul 23 – Aug 13 |
| Broccoli | Mar 18 – Apr 1 | Apr 29 – May 13 | — | Jun 25 – Jul 16 |
| Cabbage | Mar 18 – Apr 1 | Apr 22 – May 6 | — | Jun 25 – Jul 16 |
| Cauliflower | Mar 18 – Apr 1 | Apr 29 – May 13 | — | Jun 25 – Jul 16 |
| Okra | Apr 1 – Apr 15 | Jun 3 – Jun 17 | Jun 3 – Jun 17 | — |
| Basil | Apr 1 – Apr 15 | May 20 – Jun 3 | — | — |
| Peas | — | — | Apr 1 – Apr 22 | Jul 9 – Jul 30 |
| Spinach | — | — | Apr 1 – Apr 22 | Aug 6 – Aug 27 |
| Radishes | — | — | Apr 8 – May 20 | Aug 20 – Sep 10 |
| Cucumbers | Apr 15 – Apr 22 | May 27 – Jun 3 | May 20 – Jun 3 | Jul 16 – Jul 30 |
| Zucchini & Summer Squash | Apr 15 – Apr 22 | — | May 20 – Jun 3 | Jul 23 – Aug 6 |
| Winter Squash & Pumpkins | Apr 15 – Apr 22 | — | May 20 – Jun 3 | — |
| Melons & Watermelon | Apr 15 – Apr 22 | May 27 – Jun 10 | — | — |
| Carrots | — | — | Apr 22 – May 20 | Jul 9 – Jul 23 |
| Beets | — | — | Apr 22 – May 20 | Jul 23 – Aug 6 |
| Potatoes | — | — | Apr 22 – May 13 | — |
| Swiss Chard | — | — | Apr 29 – May 27 | Jul 23 – Aug 6 |
| Cilantro | — | — | Apr 29 – May 20 | Aug 6 – Aug 27 |
| Green Beans | — | — | May 20 – Jun 10 | Jul 16 – Jul 30 |
| Sweet Corn | — | — | May 20 – Jun 3 | — |
| Sweet Potatoes | — | May 27 – Jun 17 | — | — |
| Garlic | — | — | — | Sep 17 – Oct 22 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Duluth, MN weather station, 3 km away (elevation 1,427 ft (435 m)).
ZIP codes in Duluth: 55801 55802 55803 55804 55805 55806 55807 55808 55810 55811 55812 55814 55815 55816
Frost dates near Duluth
- Twig May 18 · Oct 1
- Saginaw May 18 · Oct 1
- Esko May 26 · Sep 23
- Cloquet May 26 · Sep 23
- Carlton May 26 · Sep 23
- Wrenshall Jun 1 · Sep 22
- Alborn May 27 · Sep 20
- Brookston May 26 · Sep 23
Frequently asked questions
When is the last frost in Duluth, MN?
The median last spring frost in Duluth, MN is May 13. There is still about a 10% chance of frost after May 29, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Duluth, MN?
The median first fall frost is October 1, with about a 10% chance of frost before September 18.
How long is the growing season in Duluth, MN?
About 141 days between the median last spring frost and first fall frost.
What planting zone is Duluth, MN?
Duluth, MN is in USDA hardiness zone 4b.