Fairfield, ID frost dates
Last spring frostJun 8median date
First fall frostSep 14median date
Growing season98 daysfrost-free
Hardiness zone6aZone 6a
How Fairfield compares
- In 8 years out of 10, the last spring frost in Fairfield falls between May 15 and June 28, a 44-day window. The first fall frost falls between August 29 and September 28.
- The median last frost is 25 days later than the Idaho median of May 14.
- Its 98-day growing season is longer than 10% of the 244 Idaho places with a regular frost season (state median 138 days).
- The last frost is 40 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 204 nights a year at or below 32°F.
- Compared with Boise, ID, 118 km away, the last frost here is 45 days later than there and the growing season is 82 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 15 |
| 50% (median) | June 8 |
| 10% (safe for tender plants) | June 28 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | August 29 |
| 50% (median) | September 14 |
| 90% (late) | September 28 |
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 Fairfield, ID
Fairfield, ID frost dates — last frost Jun 8, first frost Sep 14, zone 6a. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Mar 16 to Mar 30Transplant outside: May 11 to May 25
Start indoors: Mar 30 to Apr 13Transplant outside: Jun 22 to Jul 6
Start indoors: Mar 30 to Apr 13Transplant outside: Jun 22 to Jul 6
Start indoors: Apr 13 to Apr 27Transplant outside: Jun 15 to Jun 29
Start indoors: Apr 13 to Apr 27Transplant outside: May 18 to Jun 1Sow outdoors: May 11 to Jun 15Plant for fall: Jul 20 to Aug 17
Start indoors: Apr 13 to Apr 27Transplant outside: May 11 to May 25Sow outdoors: May 11 to May 25Plant for fall: Jul 6 to Jul 27
Start indoors: Apr 13 to Apr 27Transplant outside: May 25 to Jun 8
Start indoors: Apr 13 to Apr 27Transplant outside: May 18 to Jun 1
Start indoors: Apr 13 to Apr 27Transplant outside: May 25 to Jun 8
Start indoors: Apr 27 to May 11Transplant outside: Jun 29 to Jul 13Sow outdoors: Jun 29 to Jul 13
Start indoors: Apr 27 to May 11Transplant outside: Jun 15 to Jun 29
Sow outdoors: Apr 27 to May 18
Sow outdoors: Apr 27 to May 18Plant for fall: Jul 20 to Aug 10
Sow outdoors: May 4 to Jun 15Plant for fall: Aug 3 to Aug 24
Start indoors: May 11 to May 18Transplant outside: Jun 22 to Jun 29Sow outdoors: Jun 15 to Jun 29
Start indoors: May 11 to May 18Sow outdoors: Jun 15 to Jun 29
Start indoors: May 11 to May 18Sow outdoors: Jun 15 to Jun 29
Start indoors: May 11 to May 18Transplant outside: Jun 22 to Jul 6
Sow outdoors: May 18 to Jun 15
Sow outdoors: May 18 to Jun 15Plant for fall: Jul 6 to Jul 20
Sow outdoors: May 18 to Jun 8
Sow outdoors: May 25 to Jun 22
Sow outdoors: May 25 to Jun 15Plant for fall: Jul 20 to Aug 10
Sow outdoors: Jun 15 to Jul 6
Sow outdoors: Jun 15 to Jun 29
Transplant outside: Jun 22 to Jul 13
Plant for fall: Aug 31 to Oct 5
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Fairfield, ID
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 16 – Mar 30 | May 11 – May 25 | — | — |
| Peppers | Mar 30 – Apr 13 | Jun 22 – Jul 6 | — | — |
| Eggplant | Mar 30 – Apr 13 | Jun 22 – Jul 6 | — | — |
| Tomatoes | Apr 13 – Apr 27 | Jun 15 – Jun 29 | — | — |
| Lettuce | Apr 13 – Apr 27 | May 18 – Jun 1 | May 11 – Jun 15 | Jul 20 – Aug 17 |
| Kale | Apr 13 – Apr 27 | May 11 – May 25 | May 11 – May 25 | Jul 6 – Jul 27 |
| Broccoli | Apr 13 – Apr 27 | May 25 – Jun 8 | — | — |
| Cabbage | Apr 13 – Apr 27 | May 18 – Jun 1 | — | — |
| Cauliflower | Apr 13 – Apr 27 | May 25 – Jun 8 | — | — |
| Okra | Apr 27 – May 11 | Jun 29 – Jul 13 | Jun 29 – Jul 13 | — |
| Basil | Apr 27 – May 11 | Jun 15 – Jun 29 | — | — |
| Peas | — | — | Apr 27 – May 18 | — |
| Spinach | — | — | Apr 27 – May 18 | Jul 20 – Aug 10 |
| Radishes | — | — | May 4 – Jun 15 | Aug 3 – Aug 24 |
| Cucumbers | May 11 – May 18 | Jun 22 – Jun 29 | Jun 15 – Jun 29 | — |
| Zucchini & Summer Squash | May 11 – May 18 | — | Jun 15 – Jun 29 | — |
| Winter Squash & Pumpkins Warning: Your frost-free season is about 98 days, which is tight for winter squash & pumpkins (100+ days). Choose early varieties and use transplants or row covers. | May 11 – May 18 | — | Jun 15 – Jun 29 | — |
| Melons & Watermelon Warning: Your frost-free season is about 98 days, which is tight for melons & watermelon (85+ days). Choose early varieties and use transplants or row covers. | May 11 – May 18 | Jun 22 – Jul 6 | — | — |
| Carrots | — | — | May 18 – Jun 15 | — |
| Beets | — | — | May 18 – Jun 15 | Jul 6 – Jul 20 |
| Potatoes | — | — | May 18 – Jun 8 | — |
| Swiss Chard | — | — | May 25 – Jun 22 | — |
| Cilantro | — | — | May 25 – Jun 15 | Jul 20 – Aug 10 |
| Green Beans | — | — | Jun 15 – Jul 6 | — |
| Sweet Corn | — | — | Jun 15 – Jun 29 | — |
| Sweet Potatoes Warning: Your frost-free season is about 98 days, which is tight for sweet potatoes (100+ days). Choose early varieties and use transplants or row covers. | — | Jun 22 – Jul 13 | — | — |
| Garlic | — | — | — | Aug 31 – Oct 5 |
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 Fairfield Rs, ID weather station, 3 km away (elevation 5,066 ft (1,544 m)).
Frost dates near Fairfield
- Corral Jun 8 · Sep 14
- Hill City Jun 16 · Sep 6
- Ketchum frost any month
- Hailey May 13 · Oct 2
- Bellevue May 13 · Oct 2
- Bliss May 3 · Oct 1
- Sun Valley frost any month
- Gooding May 3 · Oct 1
- King Hill May 1 · Oct 3
- Shoshone Apr 24 · Oct 16
Frequently asked questions
When is the last frost in Fairfield, ID?
The median last spring frost in Fairfield, ID is June 8. There is still about a 10% chance of frost after June 28, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Fairfield, ID?
The median first fall frost is September 14, with about a 10% chance of frost before August 29.
How long is the growing season in Fairfield, ID?
About 98 days between the median last spring frost and first fall frost.
What planting zone is Fairfield, ID?
Fairfield, ID is in USDA hardiness zone 6a.