Colburn, ID frost dates
Last spring frostMay 8median date
First fall frostSep 28median date
Growing season143 daysfrost-free
Hardiness zone6bZone 6b
How Colburn compares
- In 8 years out of 10, the last spring frost in Colburn falls between April 23 and May 25, a 32-day window. The first fall frost falls between September 11 and October 11.
- The median last frost is 6 days earlier than the Idaho median of May 14.
- Its 143-day growing season is longer than 54% of the 244 Idaho places with a regular frost season (state median 138 days).
- The last frost is 16 days later than the zone 6b median of Apr 22. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 6b chart.
- The weather station records an average of 156 nights a year at or below 32°F.
- Compared with Spokane, WA, 97 km away, the last frost here is 12 days later than there and the growing season is 29 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 23 |
| 50% (median) | May 8 |
| 10% (safe for tender plants) | May 25 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 11 |
| 50% (median) | September 28 |
| 90% (late) | October 11 |
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 Colburn, ID
Colburn, ID frost dates — last frost May 8, first frost Sep 28, zone 6b. whenisthelastfrost.com
Crop
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Start indoors: Feb 13 to Feb 27Transplant outside: Apr 10 to Apr 24
Start indoors: Feb 27 to Mar 13Transplant outside: May 22 to Jun 5
Start indoors: Feb 27 to Mar 13Transplant outside: May 22 to Jun 5
Start indoors: Mar 13 to Mar 27Transplant outside: May 15 to May 29
Start indoors: Mar 13 to Mar 27Transplant outside: Apr 17 to May 1Sow outdoors: Apr 10 to May 15Plant for fall: Aug 3 to Aug 31
Start indoors: Mar 13 to Mar 27Transplant outside: Apr 10 to Apr 24Sow outdoors: Apr 10 to Apr 24Plant for fall: Jul 20 to Aug 10
Start indoors: Mar 13 to Mar 27Transplant outside: Apr 24 to May 8Plant for fall: Jun 22 to Jul 13
Start indoors: Mar 13 to Mar 27Transplant outside: Apr 17 to May 1Plant for fall: Jun 22 to Jul 13
Start indoors: Mar 13 to Mar 27Transplant outside: Apr 24 to May 8Plant for fall: Jun 22 to Jul 13
Start indoors: Mar 27 to Apr 10Transplant outside: May 29 to Jun 12Sow outdoors: May 29 to Jun 12
Start indoors: Mar 27 to Apr 10Transplant outside: May 15 to May 29
Sow outdoors: Mar 27 to Apr 17Plant for fall: Jul 6 to Jul 27
Sow outdoors: Mar 27 to Apr 17Plant for fall: Aug 3 to Aug 24
Sow outdoors: Apr 3 to May 15Plant for fall: Aug 17 to Sep 7
Start indoors: Apr 10 to Apr 17Transplant outside: May 22 to May 29Sow outdoors: May 15 to May 29Plant for fall: Jul 13 to Jul 27
Start indoors: Apr 10 to Apr 17Sow outdoors: May 15 to May 29Plant for fall: Jul 20 to Aug 3
Start indoors: Apr 10 to Apr 17Sow outdoors: May 15 to May 29
Start indoors: Apr 10 to Apr 17Transplant outside: May 22 to Jun 5
Sow outdoors: Apr 17 to May 15Plant for fall: Jul 6 to Jul 20
Sow outdoors: Apr 17 to May 15Plant for fall: Jul 20 to Aug 3
Sow outdoors: Apr 17 to May 8
Sow outdoors: Apr 24 to May 22Plant for fall: Jul 20 to Aug 3
Sow outdoors: Apr 24 to May 15Plant for fall: Aug 3 to Aug 24
Sow outdoors: May 15 to Jun 5Plant for fall: Jul 13 to Jul 27
Sow outdoors: May 15 to May 29
Transplant outside: May 22 to Jun 12
Plant for fall: Sep 14 to Oct 19
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Colburn, ID
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 13 – Feb 27 | Apr 10 – Apr 24 | — | — |
| Peppers | Feb 27 – Mar 13 | May 22 – Jun 5 | — | — |
| Eggplant | Feb 27 – Mar 13 | May 22 – Jun 5 | — | — |
| Tomatoes | Mar 13 – Mar 27 | May 15 – May 29 | — | — |
| Lettuce | Mar 13 – Mar 27 | Apr 17 – May 1 | Apr 10 – May 15 | Aug 3 – Aug 31 |
| Kale | Mar 13 – Mar 27 | Apr 10 – Apr 24 | Apr 10 – Apr 24 | Jul 20 – Aug 10 |
| Broccoli | Mar 13 – Mar 27 | Apr 24 – May 8 | — | Jun 22 – Jul 13 |
| Cabbage | Mar 13 – Mar 27 | Apr 17 – May 1 | — | Jun 22 – Jul 13 |
| Cauliflower | Mar 13 – Mar 27 | Apr 24 – May 8 | — | Jun 22 – Jul 13 |
| Okra | Mar 27 – Apr 10 | May 29 – Jun 12 | May 29 – Jun 12 | — |
| Basil | Mar 27 – Apr 10 | May 15 – May 29 | — | — |
| Peas | — | — | Mar 27 – Apr 17 | Jul 6 – Jul 27 |
| Spinach | — | — | Mar 27 – Apr 17 | Aug 3 – Aug 24 |
| Radishes | — | — | Apr 3 – May 15 | Aug 17 – Sep 7 |
| Cucumbers | Apr 10 – Apr 17 | May 22 – May 29 | May 15 – May 29 | Jul 13 – Jul 27 |
| Zucchini & Summer Squash | Apr 10 – Apr 17 | — | May 15 – May 29 | Jul 20 – Aug 3 |
| Winter Squash & Pumpkins | Apr 10 – Apr 17 | — | May 15 – May 29 | — |
| Melons & Watermelon | Apr 10 – Apr 17 | May 22 – Jun 5 | — | — |
| Carrots | — | — | Apr 17 – May 15 | Jul 6 – Jul 20 |
| Beets | — | — | Apr 17 – May 15 | Jul 20 – Aug 3 |
| Potatoes | — | — | Apr 17 – May 8 | — |
| Swiss Chard | — | — | Apr 24 – May 22 | Jul 20 – Aug 3 |
| Cilantro | — | — | Apr 24 – May 15 | Aug 3 – Aug 24 |
| Green Beans | — | — | May 15 – Jun 5 | Jul 13 – Jul 27 |
| Sweet Corn | — | — | May 15 – May 29 | — |
| Sweet Potatoes | — | May 22 – Jun 12 | — | — |
| Garlic | — | — | — | Sep 14 – Oct 19 |
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 Sandpoint Exp Stn, ID weather station, 9 km away (elevation 2,126 ft (648 m)).
Frost dates near Colburn
- Sandpoint May 8 · Sep 28
- Ponderay May 8 · Sep 28
- Kootenai May 8 · Sep 28
- Dover May 8 · Sep 28
- Sagle May 8 · Sep 28
- Laclede May 8 · Sep 28
- Coolin May 20 · Sep 13
- Cocolalla May 22 · Sep 22
- Hope May 8 · Sep 28
- Priest River May 12 · Sep 21
Frequently asked questions
When is the last frost in Colburn, ID?
The median last spring frost in Colburn, ID is May 8. There is still about a 10% chance of frost after May 25, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Colburn, ID?
The median first fall frost is September 28, with about a 10% chance of frost before September 11.
How long is the growing season in Colburn, ID?
About 143 days between the median last spring frost and first fall frost.
What planting zone is Colburn, ID?
Colburn, ID is in USDA hardiness zone 6b.