Fernwood, ID frost dates
How Fernwood compares
- In 8 years out of 10, the last spring frost in Fernwood falls between April 20 and May 18, a 28-day window. The first fall frost falls between September 18 and October 20.
- The median last frost is 11 days earlier than the Idaho median of May 14.
- Its 154-day growing season is longer than 73% of the 244 Idaho places with a regular frost season (state median 138 days).
- The last frost is 11 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 138 nights a year at or below 32°F.
- Compared with Spokane, WA, 98 km away, the last frost here is 7 days later than there and the growing season is 18 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 20 |
| 50% (median) | May 3 |
| 10% (safe for tender plants) | May 18 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 18 |
| 50% (median) | October 4 |
| 90% (late) | October 20 |
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 Fernwood, ID
Fernwood, ID frost dates — last frost May 3, first frost Oct 4, zone 6b. whenisthelastfrost.com
When to plant vegetables in Fernwood, ID
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 8 – Feb 22 | Apr 5 – Apr 19 | — | — |
| Peppers | Feb 22 – Mar 8 | May 17 – May 31 | — | — |
| Eggplant | Feb 22 – Mar 8 | May 17 – May 31 | — | — |
| Tomatoes | Mar 8 – Mar 22 | May 10 – May 24 | — | — |
| Lettuce | Mar 8 – Mar 22 | Apr 12 – Apr 26 | Apr 5 – May 10 | Aug 9 – Sep 6 |
| Kale | Mar 8 – Mar 22 | Apr 5 – Apr 19 | Apr 5 – Apr 19 | Jul 26 – Aug 16 |
| Broccoli | Mar 8 – Mar 22 | Apr 19 – May 3 | — | Jun 28 – Jul 19 |
| Cabbage | Mar 8 – Mar 22 | Apr 12 – Apr 26 | — | Jun 28 – Jul 19 |
| Cauliflower | Mar 8 – Mar 22 | Apr 19 – May 3 | — | Jun 28 – Jul 19 |
| Okra | Mar 22 – Apr 5 | May 24 – Jun 7 | May 24 – Jun 7 | — |
| Basil | Mar 22 – Apr 5 | May 10 – May 24 | — | — |
| Peas | — | — | Mar 22 – Apr 12 | Jul 12 – Aug 2 |
| Spinach | — | — | Mar 22 – Apr 12 | Aug 9 – Aug 30 |
| Radishes | — | — | Mar 29 – May 10 | Aug 23 – Sep 13 |
| Cucumbers | Apr 5 – Apr 12 | May 17 – May 24 | May 10 – May 24 | Jul 19 – Aug 2 |
| Zucchini & Summer Squash | Apr 5 – Apr 12 | — | May 10 – May 24 | Jul 26 – Aug 9 |
| Winter Squash & Pumpkins | Apr 5 – Apr 12 | — | May 10 – May 24 | — |
| Melons & Watermelon | Apr 5 – Apr 12 | May 17 – May 31 | — | — |
| Carrots | — | — | Apr 12 – May 10 | Jul 12 – Jul 26 |
| Beets | — | — | Apr 12 – May 10 | Jul 26 – Aug 9 |
| Potatoes | — | — | Apr 12 – May 3 | — |
| Swiss Chard | — | — | Apr 19 – May 17 | Jul 26 – Aug 9 |
| Cilantro | — | — | Apr 19 – May 10 | Aug 9 – Aug 30 |
| Green Beans | — | — | May 10 – May 31 | Jul 19 – Aug 2 |
| Sweet Corn | — | — | May 10 – May 24 | — |
| Sweet Potatoes | — | May 17 – Jun 7 | — | — |
| Garlic | — | — | — | Sep 20 – Oct 25 |
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 Saint Maries, ID weather station, 27 km away (elevation 2,152 ft (656 m)).
Frost dates near Fernwood
- Santa May 3 · Oct 4
- Clarkia May 16 · Sep 23
- Saint Maries May 3 · Oct 4
- Bovill May 16 · Sep 23
- Harvard May 15 · Sep 21
- Calder May 5 · Oct 2
- Deary May 16 · Sep 23
- Desmet May 15 · Sep 21
- Tensed May 11 · Oct 5
- Elk River May 16 · Sep 23
Frequently asked questions
When is the last frost in Fernwood, ID?
The median last spring frost in Fernwood, ID is May 3. There is still about a 10% chance of frost after May 18, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Fernwood, ID?
The median first fall frost is October 4, with about a 10% chance of frost before September 18.
How long is the growing season in Fernwood, ID?
About 154 days between the median last spring frost and first fall frost.
What planting zone is Fernwood, ID?
Fernwood, ID is in USDA hardiness zone 6b.