Richfield, ID frost dates
Last spring frostMay 24median date
First fall frostSep 26median date
Growing season125 daysfrost-free
Hardiness zone6aZone 6a
How Richfield compares
- In 8 years out of 10, the last spring frost in Richfield falls between May 6 and June 14, a 39-day window. The first fall frost falls between September 10 and October 10.
- The median last frost is 10 days later than the Idaho median of May 14.
- Its 125-day growing season is longer than 29% of the 244 Idaho places with a regular frost season (state median 138 days).
- The last frost is 25 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.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 6 |
| 50% (median) | May 24 |
| 10% (safe for tender plants) | June 14 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 10 |
| 50% (median) | September 26 |
| 90% (late) | October 10 |
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 Richfield, ID
Richfield, ID frost dates — last frost May 24, first frost Sep 26, zone 6a. whenisthelastfrost.com
Crop
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Start indoors: Mar 1 to Mar 15Transplant outside: Apr 26 to May 10
Start indoors: Mar 15 to Mar 29Transplant outside: Jun 7 to Jun 21
Start indoors: Mar 15 to Mar 29Transplant outside: Jun 7 to Jun 21
Start indoors: Mar 29 to Apr 12Transplant outside: May 31 to Jun 14
Start indoors: Mar 29 to Apr 12Transplant outside: May 3 to May 17Sow outdoors: Apr 26 to May 31Plant for fall: Aug 1 to Aug 29
Start indoors: Mar 29 to Apr 12Transplant outside: Apr 26 to May 10Sow outdoors: Apr 26 to May 10Plant for fall: Jul 18 to Aug 8
Start indoors: Mar 29 to Apr 12Transplant outside: May 10 to May 24Plant for fall: Jun 20 to Jul 11
Start indoors: Mar 29 to Apr 12Transplant outside: May 3 to May 17Plant for fall: Jun 20 to Jul 11
Start indoors: Mar 29 to Apr 12Transplant outside: May 10 to May 24Plant for fall: Jun 20 to Jul 11
Start indoors: Apr 12 to Apr 26Transplant outside: Jun 14 to Jun 28Sow outdoors: Jun 14 to Jun 28
Start indoors: Apr 12 to Apr 26Transplant outside: May 31 to Jun 14
Sow outdoors: Apr 12 to May 3Plant for fall: Jul 4 to Jul 25
Sow outdoors: Apr 12 to May 3Plant for fall: Aug 1 to Aug 22
Sow outdoors: Apr 19 to May 31Plant for fall: Aug 15 to Sep 5
Start indoors: Apr 26 to May 3Transplant outside: Jun 7 to Jun 14Sow outdoors: May 31 to Jun 14Plant for fall: Jul 11 to Jul 25
Start indoors: Apr 26 to May 3Sow outdoors: May 31 to Jun 14Plant for fall: Jul 18 to Aug 1
Start indoors: Apr 26 to May 3Sow outdoors: May 31 to Jun 14
Start indoors: Apr 26 to May 3Transplant outside: Jun 7 to Jun 21
Sow outdoors: May 3 to May 31Plant for fall: Jul 4 to Jul 18
Sow outdoors: May 3 to May 31Plant for fall: Jul 18 to Aug 1
Sow outdoors: May 3 to May 24
Sow outdoors: May 10 to Jun 7Plant for fall: Jul 18 to Aug 1
Sow outdoors: May 10 to May 31Plant for fall: Aug 1 to Aug 22
Sow outdoors: May 31 to Jun 21Plant for fall: Jul 11 to Jul 25
Sow outdoors: May 31 to Jun 14
Transplant outside: Jun 7 to Jun 28
Plant for fall: Sep 12 to Oct 17
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Richfield, ID
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 1 – Mar 15 | Apr 26 – May 10 | — | — |
| Peppers | Mar 15 – Mar 29 | Jun 7 – Jun 21 | — | — |
| Eggplant | Mar 15 – Mar 29 | Jun 7 – Jun 21 | — | — |
| Tomatoes | Mar 29 – Apr 12 | May 31 – Jun 14 | — | — |
| Lettuce | Mar 29 – Apr 12 | May 3 – May 17 | Apr 26 – May 31 | Aug 1 – Aug 29 |
| Kale | Mar 29 – Apr 12 | Apr 26 – May 10 | Apr 26 – May 10 | Jul 18 – Aug 8 |
| Broccoli | Mar 29 – Apr 12 | May 10 – May 24 | — | Jun 20 – Jul 11 |
| Cabbage | Mar 29 – Apr 12 | May 3 – May 17 | — | Jun 20 – Jul 11 |
| Cauliflower | Mar 29 – Apr 12 | May 10 – May 24 | — | Jun 20 – Jul 11 |
| Okra | Apr 12 – Apr 26 | Jun 14 – Jun 28 | Jun 14 – Jun 28 | — |
| Basil | Apr 12 – Apr 26 | May 31 – Jun 14 | — | — |
| Peas | — | — | Apr 12 – May 3 | Jul 4 – Jul 25 |
| Spinach | — | — | Apr 12 – May 3 | Aug 1 – Aug 22 |
| Radishes | — | — | Apr 19 – May 31 | Aug 15 – Sep 5 |
| Cucumbers | Apr 26 – May 3 | Jun 7 – Jun 14 | May 31 – Jun 14 | Jul 11 – Jul 25 |
| Zucchini & Summer Squash | Apr 26 – May 3 | — | May 31 – Jun 14 | Jul 18 – Aug 1 |
| Winter Squash & Pumpkins | Apr 26 – May 3 | — | May 31 – Jun 14 | — |
| Melons & Watermelon | Apr 26 – May 3 | Jun 7 – Jun 21 | — | — |
| Carrots | — | — | May 3 – May 31 | Jul 4 – Jul 18 |
| Beets | — | — | May 3 – May 31 | Jul 18 – Aug 1 |
| Potatoes | — | — | May 3 – May 24 | — |
| Swiss Chard | — | — | May 10 – Jun 7 | Jul 18 – Aug 1 |
| Cilantro | — | — | May 10 – May 31 | Aug 1 – Aug 22 |
| Green Beans | — | — | May 31 – Jun 21 | Jul 11 – Jul 25 |
| Sweet Corn | — | — | May 31 – Jun 14 | — |
| Sweet Potatoes | — | Jun 7 – Jun 28 | — | — |
| 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 Richfield, ID weather station, about 1 km away (elevation 4,308 ft (1,313 m)).
Frost dates near Richfield
- Dietrich Apr 24 · Oct 16
- Shoshone Apr 24 · Oct 16
- Picabo Jun 16 · Sep 9
- Carey Jun 16 · Sep 9
- Bellevue May 13 · Oct 2
- Jerome May 2 · Oct 14
- Gooding May 3 · Oct 1
- Hazelton May 7 · Oct 5
- Eden May 7 · Oct 5
- Hailey May 13 · Oct 2
Frequently asked questions
When is the last frost in Richfield, ID?
The median last spring frost in Richfield, ID is May 24. There is still about a 10% chance of frost after June 14, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Richfield, ID?
The median first fall frost is September 26, with about a 10% chance of frost before September 10.
How long is the growing season in Richfield, ID?
About 125 days between the median last spring frost and first fall frost.
What planting zone is Richfield, ID?
Richfield, ID is in USDA hardiness zone 6a.