Thatcher, ID frost dates
Last spring frostMay 29median date
First fall frostSep 17median date
Growing season111 daysfrost-free
Hardiness zone6aZone 6a
How Thatcher compares
- In 8 years out of 10, the last spring frost in Thatcher falls between May 11 and June 16, a 36-day window. The first fall frost falls between September 1 and October 1.
- The median last frost is 15 days later than the Idaho median of May 14.
- Its 111-day growing season is longer than 17% of the 244 Idaho places with a regular frost season (state median 138 days).
- The last frost is 30 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 200 nights a year at or below 32°F.
- Compared with Logan, UT, 74 km away, the last frost here is 21 days later than there and the growing season is 36 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 11 |
| 50% (median) | May 29 |
| 10% (safe for tender plants) | June 16 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 1 |
| 50% (median) | September 17 |
| 90% (late) | October 1 |
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 Thatcher, ID
Thatcher, ID frost dates — last frost May 29, first frost Sep 17, zone 6a. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Mar 6 to Mar 20Transplant outside: May 1 to May 15
Start indoors: Mar 20 to Apr 3Transplant outside: Jun 12 to Jun 26
Start indoors: Mar 20 to Apr 3Transplant outside: Jun 12 to Jun 26
Start indoors: Apr 3 to Apr 17Transplant outside: Jun 5 to Jun 19
Start indoors: Apr 3 to Apr 17Transplant outside: May 8 to May 22Sow outdoors: May 1 to Jun 5Plant for fall: Jul 23 to Aug 20
Start indoors: Apr 3 to Apr 17Transplant outside: May 1 to May 15Sow outdoors: May 1 to May 15Plant for fall: Jul 9 to Jul 30
Start indoors: Apr 3 to Apr 17Transplant outside: May 15 to May 29
Start indoors: Apr 3 to Apr 17Transplant outside: May 8 to May 22
Start indoors: Apr 3 to Apr 17Transplant outside: May 15 to May 29
Start indoors: Apr 17 to May 1Transplant outside: Jun 19 to Jul 3Sow outdoors: Jun 19 to Jul 3
Start indoors: Apr 17 to May 1Transplant outside: Jun 5 to Jun 19
Sow outdoors: Apr 17 to May 8Plant for fall: Jun 25 to Jul 16
Sow outdoors: Apr 17 to May 8Plant for fall: Jul 23 to Aug 13
Sow outdoors: Apr 24 to Jun 5Plant for fall: Aug 6 to Aug 27
Start indoors: May 1 to May 8Transplant outside: Jun 12 to Jun 19Sow outdoors: Jun 5 to Jun 19
Start indoors: May 1 to May 8Sow outdoors: Jun 5 to Jun 19Plant for fall: Jul 9 to Jul 23
Start indoors: May 1 to May 8Sow outdoors: Jun 5 to Jun 19
Start indoors: May 1 to May 8Transplant outside: Jun 12 to Jun 26
Sow outdoors: May 8 to Jun 5Plant for fall: Jun 25 to Jul 9
Sow outdoors: May 8 to Jun 5Plant for fall: Jul 9 to Jul 23
Sow outdoors: May 8 to May 29
Sow outdoors: May 15 to Jun 12Plant for fall: Jul 9 to Jul 23
Sow outdoors: May 15 to Jun 5Plant for fall: Jul 23 to Aug 13
Sow outdoors: Jun 5 to Jun 26
Sow outdoors: Jun 5 to Jun 19
Transplant outside: Jun 12 to Jul 3
Plant for fall: Sep 3 to Oct 8
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Thatcher, ID
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 6 – Mar 20 | May 1 – May 15 | — | — |
| Peppers | Mar 20 – Apr 3 | Jun 12 – Jun 26 | — | — |
| Eggplant | Mar 20 – Apr 3 | Jun 12 – Jun 26 | — | — |
| Tomatoes | Apr 3 – Apr 17 | Jun 5 – Jun 19 | — | — |
| Lettuce | Apr 3 – Apr 17 | May 8 – May 22 | May 1 – Jun 5 | Jul 23 – Aug 20 |
| Kale | Apr 3 – Apr 17 | May 1 – May 15 | May 1 – May 15 | Jul 9 – Jul 30 |
| Broccoli | Apr 3 – Apr 17 | May 15 – May 29 | — | — |
| Cabbage | Apr 3 – Apr 17 | May 8 – May 22 | — | — |
| Cauliflower | Apr 3 – Apr 17 | May 15 – May 29 | — | — |
| Okra | Apr 17 – May 1 | Jun 19 – Jul 3 | Jun 19 – Jul 3 | — |
| Basil | Apr 17 – May 1 | Jun 5 – Jun 19 | — | — |
| Peas | — | — | Apr 17 – May 8 | Jun 25 – Jul 16 |
| Spinach | — | — | Apr 17 – May 8 | Jul 23 – Aug 13 |
| Radishes | — | — | Apr 24 – Jun 5 | Aug 6 – Aug 27 |
| Cucumbers | May 1 – May 8 | Jun 12 – Jun 19 | Jun 5 – Jun 19 | — |
| Zucchini & Summer Squash | May 1 – May 8 | — | Jun 5 – Jun 19 | Jul 9 – Jul 23 |
| Winter Squash & Pumpkins Warning: Your frost-free season is about 111 days, which is tight for winter squash & pumpkins (100+ days). Choose early varieties and use transplants or row covers. | May 1 – May 8 | — | Jun 5 – Jun 19 | — |
| Melons & Watermelon | May 1 – May 8 | Jun 12 – Jun 26 | — | — |
| Carrots | — | — | May 8 – Jun 5 | Jun 25 – Jul 9 |
| Beets | — | — | May 8 – Jun 5 | Jul 9 – Jul 23 |
| Potatoes | — | — | May 8 – May 29 | — |
| Swiss Chard | — | — | May 15 – Jun 12 | Jul 9 – Jul 23 |
| Cilantro | — | — | May 15 – Jun 5 | Jul 23 – Aug 13 |
| Green Beans | — | — | Jun 5 – Jun 26 | — |
| Sweet Corn | — | — | Jun 5 – Jun 19 | — |
| Sweet Potatoes Warning: Your frost-free season is about 111 days, which is tight for sweet potatoes (100+ days). Choose early varieties and use transplants or row covers. | — | Jun 12 – Jul 3 | — | — |
| Garlic | — | — | — | Sep 3 – Oct 8 |
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 Grace, ID weather station, 23 km away (elevation 5,551 ft (1,692 m)).
Frost dates near Thatcher
- Grace May 29 · Sep 17
- Bern Jun 17 · Sep 3
- Swanlake May 31 · Sep 18
- Paris Jun 17 · Sep 3
- Georgetown Jun 17 · Sep 3
- Montpelier Jun 17 · Sep 3
- Bloomington May 19 · Sep 21
- Clifton May 16 · Sep 28
- Preston May 16 · Sep 28
- Soda Springs frost any month
Frequently asked questions
When is the last frost in Thatcher, ID?
The median last spring frost in Thatcher, ID is May 29. 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 Thatcher, ID?
The median first fall frost is September 17, with about a 10% chance of frost before September 1.
How long is the growing season in Thatcher, ID?
About 111 days between the median last spring frost and first fall frost.
What planting zone is Thatcher, ID?
Thatcher, ID is in USDA hardiness zone 6a.