Coleraine, MN frost dates
Last spring frostMay 17median date
First fall frostSep 24median date
Growing season130 daysfrost-free
Hardiness zone4aZone 4a
How Coleraine compares
- In 8 years out of 10, the last spring frost in Coleraine falls between May 3 and May 31, a 28-day window. The first fall frost falls between September 10 and October 7.
- The median last frost is 12 days later than the Minnesota median of May 5.
- Its 130-day growing season is longer than 7% of the 801 Minnesota places with a regular frost season (state median 151 days).
- The last frost is 5 days later than the zone 4a median of May 12. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 4a chart.
- The weather station records an average of 187 nights a year at or below 32°F.
- Compared with Duluth, MN, 113 km away, the last frost here is 3 days later than there and the growing season is 21 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 3 |
| 50% (median) | May 17 |
| 10% (safe for tender plants) | May 31 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 10 |
| 50% (median) | September 24 |
| 90% (late) | October 7 |
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 Coleraine, MN
Coleraine, MN frost dates — last frost May 17, first frost Sep 24, zone 4a. whenisthelastfrost.com
Crop
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Start indoors: Feb 22 to Mar 8Transplant outside: Apr 19 to May 3
Start indoors: Mar 8 to Mar 22Transplant outside: May 31 to Jun 14
Start indoors: Mar 8 to Mar 22Transplant outside: May 31 to Jun 14
Start indoors: Mar 22 to Apr 5Transplant outside: May 24 to Jun 7
Start indoors: Mar 22 to Apr 5Transplant outside: Apr 26 to May 10Sow outdoors: Apr 19 to May 24Plant for fall: Jul 30 to Aug 27
Start indoors: Mar 22 to Apr 5Transplant outside: Apr 19 to May 3Sow outdoors: Apr 19 to May 3Plant for fall: Jul 16 to Aug 6
Start indoors: Mar 22 to Apr 5Transplant outside: May 3 to May 17Plant for fall: Jun 18 to Jul 9
Start indoors: Mar 22 to Apr 5Transplant outside: Apr 26 to May 10Plant for fall: Jun 18 to Jul 9
Start indoors: Mar 22 to Apr 5Transplant outside: May 3 to May 17Plant for fall: Jun 18 to Jul 9
Start indoors: Apr 5 to Apr 19Transplant outside: Jun 7 to Jun 21Sow outdoors: Jun 7 to Jun 21
Start indoors: Apr 5 to Apr 19Transplant outside: May 24 to Jun 7
Sow outdoors: Apr 5 to Apr 26Plant for fall: Jul 2 to Jul 23
Sow outdoors: Apr 5 to Apr 26Plant for fall: Jul 30 to Aug 20
Sow outdoors: Apr 12 to May 24Plant for fall: Aug 13 to Sep 3
Start indoors: Apr 19 to Apr 26Transplant outside: May 31 to Jun 7Sow outdoors: May 24 to Jun 7Plant for fall: Jul 9 to Jul 23
Start indoors: Apr 19 to Apr 26Sow outdoors: May 24 to Jun 7Plant for fall: Jul 16 to Jul 30
Start indoors: Apr 19 to Apr 26Sow outdoors: May 24 to Jun 7
Start indoors: Apr 19 to Apr 26Transplant outside: May 31 to Jun 14
Sow outdoors: Apr 26 to May 24Plant for fall: Jul 2 to Jul 16
Sow outdoors: Apr 26 to May 24Plant for fall: Jul 16 to Jul 30
Sow outdoors: Apr 26 to May 17
Sow outdoors: May 3 to May 31Plant for fall: Jul 16 to Jul 30
Sow outdoors: May 3 to May 24Plant for fall: Jul 30 to Aug 20
Sow outdoors: May 24 to Jun 14Plant for fall: Jul 9 to Jul 23
Sow outdoors: May 24 to Jun 7
Transplant outside: May 31 to Jun 21
Plant for fall: Sep 10 to Oct 15
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Coleraine, MN
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 22 – Mar 8 | Apr 19 – May 3 | — | — |
| Peppers | Mar 8 – Mar 22 | May 31 – Jun 14 | — | — |
| Eggplant | Mar 8 – Mar 22 | May 31 – Jun 14 | — | — |
| Tomatoes | Mar 22 – Apr 5 | May 24 – Jun 7 | — | — |
| Lettuce | Mar 22 – Apr 5 | Apr 26 – May 10 | Apr 19 – May 24 | Jul 30 – Aug 27 |
| Kale | Mar 22 – Apr 5 | Apr 19 – May 3 | Apr 19 – May 3 | Jul 16 – Aug 6 |
| Broccoli | Mar 22 – Apr 5 | May 3 – May 17 | — | Jun 18 – Jul 9 |
| Cabbage | Mar 22 – Apr 5 | Apr 26 – May 10 | — | Jun 18 – Jul 9 |
| Cauliflower | Mar 22 – Apr 5 | May 3 – May 17 | — | Jun 18 – Jul 9 |
| Okra | Apr 5 – Apr 19 | Jun 7 – Jun 21 | Jun 7 – Jun 21 | — |
| Basil | Apr 5 – Apr 19 | May 24 – Jun 7 | — | — |
| Peas | — | — | Apr 5 – Apr 26 | Jul 2 – Jul 23 |
| Spinach | — | — | Apr 5 – Apr 26 | Jul 30 – Aug 20 |
| Radishes | — | — | Apr 12 – May 24 | Aug 13 – Sep 3 |
| Cucumbers | Apr 19 – Apr 26 | May 31 – Jun 7 | May 24 – Jun 7 | Jul 9 – Jul 23 |
| Zucchini & Summer Squash | Apr 19 – Apr 26 | — | May 24 – Jun 7 | Jul 16 – Jul 30 |
| Winter Squash & Pumpkins | Apr 19 – Apr 26 | — | May 24 – Jun 7 | — |
| Melons & Watermelon | Apr 19 – Apr 26 | May 31 – Jun 14 | — | — |
| Carrots | — | — | Apr 26 – May 24 | Jul 2 – Jul 16 |
| Beets | — | — | Apr 26 – May 24 | Jul 16 – Jul 30 |
| Potatoes | — | — | Apr 26 – May 17 | — |
| Swiss Chard | — | — | May 3 – May 31 | Jul 16 – Jul 30 |
| Cilantro | — | — | May 3 – May 24 | Jul 30 – Aug 20 |
| Green Beans | — | — | May 24 – Jun 14 | Jul 9 – Jul 23 |
| Sweet Corn | — | — | May 24 – Jun 7 | — |
| Sweet Potatoes | — | May 31 – Jun 21 | — | — |
| Garlic | — | — | — | Sep 10 – Oct 15 |
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 Grand Rpds Forest Lab, MN weather station, 7 km away (elevation 1,309 ft (399 m)).
Frost dates near Coleraine
- Taconite May 17 · Sep 24
- Bovey May 17 · Sep 24
- Grand Rapids May 17 · Sep 24
- Marble May 17 · Sep 24
- Calumet May 17 · Sep 24
- Cohasset May 16 · Oct 1
- Pengilly May 17 · Sep 24
- Warba May 17 · Sep 24
- Nashwauk Jun 5 · Sep 8
- Goodland May 17 · Sep 24
Frequently asked questions
When is the last frost in Coleraine, MN?
The median last spring frost in Coleraine, MN is May 17. There is still about a 10% chance of frost after May 31, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Coleraine, MN?
The median first fall frost is September 24, with about a 10% chance of frost before September 10.
How long is the growing season in Coleraine, MN?
About 130 days between the median last spring frost and first fall frost.
What planting zone is Coleraine, MN?
Coleraine, MN is in USDA hardiness zone 4a.