Kingston, ID frost dates
How Kingston compares
- In 8 years out of 10, the last spring frost in Kingston falls between April 30 and June 3, a 34-day window. The first fall frost falls between September 9 and October 9.
- The median last frost is the same as the Idaho median of May 14.
- Its 135-day growing season is longer than 42% of the 244 Idaho places with a regular frost season (state median 138 days).
- The last frost is 22 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 147 nights a year at or below 32°F.
- Compared with Spokane, WA, 84 km away, the last frost here is 18 days later than there and the growing season is 37 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 30 |
| 50% (median) | May 14 |
| 10% (safe for tender plants) | June 3 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 9 |
| 50% (median) | September 26 |
| 90% (late) | October 9 |
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 Kingston, ID
Kingston, ID frost dates — last frost May 14, first frost Sep 26, zone 6b. whenisthelastfrost.com
When to plant vegetables in Kingston, ID
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 19 – Mar 5 | Apr 16 – Apr 30 | — | — |
| Peppers | Mar 5 – Mar 19 | May 28 – Jun 11 | — | — |
| Eggplant | Mar 5 – Mar 19 | May 28 – Jun 11 | — | — |
| Tomatoes | Mar 19 – Apr 2 | May 21 – Jun 4 | — | — |
| Lettuce | Mar 19 – Apr 2 | Apr 23 – May 7 | Apr 16 – May 21 | Aug 1 – Aug 29 |
| Kale | Mar 19 – Apr 2 | Apr 16 – Apr 30 | Apr 16 – Apr 30 | Jul 18 – Aug 8 |
| Broccoli | Mar 19 – Apr 2 | Apr 30 – May 14 | — | Jun 20 – Jul 11 |
| Cabbage | Mar 19 – Apr 2 | Apr 23 – May 7 | — | Jun 20 – Jul 11 |
| Cauliflower | Mar 19 – Apr 2 | Apr 30 – May 14 | — | Jun 20 – Jul 11 |
| Okra | Apr 2 – Apr 16 | Jun 4 – Jun 18 | Jun 4 – Jun 18 | — |
| Basil | Apr 2 – Apr 16 | May 21 – Jun 4 | — | — |
| Peas | — | — | Apr 2 – Apr 23 | Jul 4 – Jul 25 |
| Spinach | — | — | Apr 2 – Apr 23 | Aug 1 – Aug 22 |
| Radishes | — | — | Apr 9 – May 21 | Aug 15 – Sep 5 |
| Cucumbers | Apr 16 – Apr 23 | May 28 – Jun 4 | May 21 – Jun 4 | Jul 11 – Jul 25 |
| Zucchini & Summer Squash | Apr 16 – Apr 23 | — | May 21 – Jun 4 | Jul 18 – Aug 1 |
| Winter Squash & Pumpkins | Apr 16 – Apr 23 | — | May 21 – Jun 4 | — |
| Melons & Watermelon | Apr 16 – Apr 23 | May 28 – Jun 11 | — | — |
| Carrots | — | — | Apr 23 – May 21 | Jul 4 – Jul 18 |
| Beets | — | — | Apr 23 – May 21 | Jul 18 – Aug 1 |
| Potatoes | — | — | Apr 23 – May 14 | — |
| Swiss Chard | — | — | Apr 30 – May 28 | Jul 18 – Aug 1 |
| Cilantro | — | — | Apr 30 – May 21 | Aug 1 – Aug 22 |
| Green Beans | — | — | May 21 – Jun 11 | Jul 11 – Jul 25 |
| Sweet Corn | — | — | May 21 – Jun 4 | — |
| Sweet Potatoes | — | May 28 – Jun 18 | — | — |
| Garlic | — | — | — | Sep 12 – Oct 17 |
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 Kellogg, ID weather station, 13 km away (elevation 2,379 ft (725 m)).
Frost dates near Kingston
- Pinehurst May 14 · Sep 26
- Smelterville May 14 · Sep 26
- Cataldo May 14 · Sep 26
- Kellogg May 14 · Sep 26
- Osburn May 14 · Sep 26
- Medimont May 3 · Oct 4
- Silverton May 5 · Oct 2
- Wallace May 5 · Oct 2
- Calder May 5 · Oct 2
- Murray May 31 · Sep 5
Frequently asked questions
When is the last frost in Kingston, ID?
The median last spring frost in Kingston, ID is May 14. There is still about a 10% chance of frost after June 3, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Kingston, ID?
The median first fall frost is September 26, with about a 10% chance of frost before September 9.
How long is the growing season in Kingston, ID?
About 135 days between the median last spring frost and first fall frost.
What planting zone is Kingston, ID?
Kingston, ID is in USDA hardiness zone 6b.