Holbrook, ID frost dates
Last spring frostMay 22median date
First fall frostSep 20median date
Growing season121 daysfrost-free
Hardiness zone6aZone 6a
How Holbrook compares
- In 8 years out of 10, the last spring frost in Holbrook falls between May 6 and June 16, a 41-day window. The first fall frost falls between September 4 and October 6.
- The median last frost is 8 days later than the Idaho median of May 14.
- Its 121-day growing season is longer than 20% of the 244 Idaho places with a regular frost season (state median 138 days).
- The last frost is 23 days later than the zone 6a median of Apr 29. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 6a chart.
- The weather station records an average of 185 nights a year at or below 32°F.
- Compared with Pocatello, ID, 77 km away, the last frost here is 20 days later than there and the growing season is 41 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 6 |
| 50% (median) | May 22 |
| 10% (safe for tender plants) | June 16 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 4 |
| 50% (median) | September 20 |
| 90% (late) | October 6 |
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 Holbrook, ID
Holbrook, ID frost dates — last frost May 22, first frost Sep 20, zone 6a. whenisthelastfrost.com
Crop
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Start indoors: Feb 27 to Mar 13Transplant outside: Apr 24 to May 8
Start indoors: Mar 13 to Mar 27Transplant outside: Jun 5 to Jun 19
Start indoors: Mar 13 to Mar 27Transplant outside: Jun 5 to Jun 19
Start indoors: Mar 27 to Apr 10Transplant outside: May 29 to Jun 12
Start indoors: Mar 27 to Apr 10Transplant outside: May 1 to May 15Sow outdoors: Apr 24 to May 29Plant for fall: Jul 26 to Aug 23
Start indoors: Mar 27 to Apr 10Transplant outside: Apr 24 to May 8Sow outdoors: Apr 24 to May 8Plant for fall: Jul 12 to Aug 2
Start indoors: Mar 27 to Apr 10Transplant outside: May 8 to May 22Plant for fall: Jun 14 to Jul 5
Start indoors: Mar 27 to Apr 10Transplant outside: May 1 to May 15Plant for fall: Jun 14 to Jul 5
Start indoors: Mar 27 to Apr 10Transplant outside: May 8 to May 22Plant for fall: Jun 14 to Jul 5
Start indoors: Apr 10 to Apr 24Transplant outside: Jun 12 to Jun 26Sow outdoors: Jun 12 to Jun 26
Start indoors: Apr 10 to Apr 24Transplant outside: May 29 to Jun 12
Sow outdoors: Apr 10 to May 1Plant for fall: Jun 28 to Jul 19
Sow outdoors: Apr 10 to May 1Plant for fall: Jul 26 to Aug 16
Sow outdoors: Apr 17 to May 29Plant for fall: Aug 9 to Aug 30
Start indoors: Apr 24 to May 1Transplant outside: Jun 5 to Jun 12Sow outdoors: May 29 to Jun 12Plant for fall: Jul 5 to Jul 19
Start indoors: Apr 24 to May 1Sow outdoors: May 29 to Jun 12Plant for fall: Jul 12 to Jul 26
Start indoors: Apr 24 to May 1Sow outdoors: May 29 to Jun 12
Start indoors: Apr 24 to May 1Transplant outside: Jun 5 to Jun 19
Sow outdoors: May 1 to May 29Plant for fall: Jun 28 to Jul 12
Sow outdoors: May 1 to May 29Plant for fall: Jul 12 to Jul 26
Sow outdoors: May 1 to May 22
Sow outdoors: May 8 to Jun 5Plant for fall: Jul 12 to Jul 26
Sow outdoors: May 8 to May 29Plant for fall: Jul 26 to Aug 16
Sow outdoors: May 29 to Jun 19Plant for fall: Jul 5 to Jul 19
Sow outdoors: May 29 to Jun 12
Transplant outside: Jun 5 to Jun 26
Plant for fall: Sep 6 to Oct 11
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Holbrook, ID
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 27 – Mar 13 | Apr 24 – May 8 | — | — |
| Peppers | Mar 13 – Mar 27 | Jun 5 – Jun 19 | — | — |
| Eggplant | Mar 13 – Mar 27 | Jun 5 – Jun 19 | — | — |
| Tomatoes | Mar 27 – Apr 10 | May 29 – Jun 12 | — | — |
| Lettuce | Mar 27 – Apr 10 | May 1 – May 15 | Apr 24 – May 29 | Jul 26 – Aug 23 |
| Kale | Mar 27 – Apr 10 | Apr 24 – May 8 | Apr 24 – May 8 | Jul 12 – Aug 2 |
| Broccoli | Mar 27 – Apr 10 | May 8 – May 22 | — | Jun 14 – Jul 5 |
| Cabbage | Mar 27 – Apr 10 | May 1 – May 15 | — | Jun 14 – Jul 5 |
| Cauliflower | Mar 27 – Apr 10 | May 8 – May 22 | — | Jun 14 – Jul 5 |
| Okra | Apr 10 – Apr 24 | Jun 12 – Jun 26 | Jun 12 – Jun 26 | — |
| Basil | Apr 10 – Apr 24 | May 29 – Jun 12 | — | — |
| Peas | — | — | Apr 10 – May 1 | Jun 28 – Jul 19 |
| Spinach | — | — | Apr 10 – May 1 | Jul 26 – Aug 16 |
| Radishes | — | — | Apr 17 – May 29 | Aug 9 – Aug 30 |
| Cucumbers | Apr 24 – May 1 | Jun 5 – Jun 12 | May 29 – Jun 12 | Jul 5 – Jul 19 |
| Zucchini & Summer Squash | Apr 24 – May 1 | — | May 29 – Jun 12 | Jul 12 – Jul 26 |
| Winter Squash & Pumpkins | Apr 24 – May 1 | — | May 29 – Jun 12 | — |
| Melons & Watermelon | Apr 24 – May 1 | Jun 5 – Jun 19 | — | — |
| Carrots | — | — | May 1 – May 29 | Jun 28 – Jul 12 |
| Beets | — | — | May 1 – May 29 | Jul 12 – Jul 26 |
| Potatoes | — | — | May 1 – May 22 | — |
| Swiss Chard | — | — | May 8 – Jun 5 | Jul 12 – Jul 26 |
| Cilantro | — | — | May 8 – May 29 | Jul 26 – Aug 16 |
| Green Beans | — | — | May 29 – Jun 19 | Jul 5 – Jul 19 |
| Sweet Corn | — | — | May 29 – Jun 12 | — |
| Sweet Potatoes | — | Jun 5 – Jun 26 | — | — |
| Garlic | — | — | — | Sep 6 – Oct 11 |
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 Malad City, ID weather station, 30 km away (elevation 4,472 ft (1,363 m)).
Frost dates near Holbrook
- Malad City May 22 · Sep 20
- Arbon May 23 · Sep 24
- Rockland May 20 · Sep 26
- Downey May 31 · Sep 18
- Clifton May 16 · Sep 28
- Dayton May 16 · Sep 28
- Weston May 16 · Sep 28
- American Falls May 20 · Sep 26
- Swanlake May 31 · Sep 18
- Arimo May 23 · Sep 24
Frequently asked questions
When is the last frost in Holbrook, ID?
The median last spring frost in Holbrook, ID is May 22. There is still about a 10% chance of frost after June 16, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Holbrook, ID?
The median first fall frost is September 20, with about a 10% chance of frost before September 4.
How long is the growing season in Holbrook, ID?
About 121 days between the median last spring frost and first fall frost.
What planting zone is Holbrook, ID?
Holbrook, ID is in USDA hardiness zone 6a.