Cambridge, ID frost dates
Last spring frostMay 15median date
First fall frostSep 27median date
Growing season135 daysfrost-free
Hardiness zone7aZone 7a
How Cambridge compares
- In 8 years out of 10, the last spring frost in Cambridge falls between April 29 and June 4, a 36-day window. The first fall frost falls between September 12 and October 9.
- The median last frost is 1 day later than 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 29 days later than the zone 7a median of Apr 16. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 7a chart.
- The weather station records an average of 157 nights a year at or below 32°F.
- Compared with Caldwell, ID, 103 km away, the last frost here is 22 days later than there and the growing season is 43 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 29 |
| 50% (median) | May 15 |
| 10% (safe for tender plants) | June 4 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 12 |
| 50% (median) | September 27 |
| 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 Cambridge, ID
Cambridge, ID frost dates — last frost May 15, first frost Sep 27, zone 7a. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Feb 20 to Mar 6Transplant outside: Apr 17 to May 1
Start indoors: Mar 6 to Mar 20Transplant outside: May 29 to Jun 12
Start indoors: Mar 6 to Mar 20Transplant outside: May 29 to Jun 12
Start indoors: Mar 20 to Apr 3Transplant outside: May 22 to Jun 5
Start indoors: Mar 20 to Apr 3Transplant outside: Apr 24 to May 8Sow outdoors: Apr 17 to May 22Plant for fall: Aug 2 to Aug 30
Start indoors: Mar 20 to Apr 3Transplant outside: Apr 17 to May 1Sow outdoors: Apr 17 to May 1Plant for fall: Jul 19 to Aug 9
Start indoors: Mar 20 to Apr 3Transplant outside: May 1 to May 15Plant for fall: Jun 21 to Jul 12
Start indoors: Mar 20 to Apr 3Transplant outside: Apr 24 to May 8Plant for fall: Jun 21 to Jul 12
Start indoors: Mar 20 to Apr 3Transplant outside: May 1 to May 15Plant for fall: Jun 21 to Jul 12
Start indoors: Apr 3 to Apr 17Transplant outside: Jun 5 to Jun 19Sow outdoors: Jun 5 to Jun 19
Start indoors: Apr 3 to Apr 17Transplant outside: May 22 to Jun 5
Sow outdoors: Apr 3 to Apr 24Plant for fall: Jul 5 to Jul 26
Sow outdoors: Apr 3 to Apr 24Plant for fall: Aug 2 to Aug 23
Sow outdoors: Apr 10 to May 22Plant for fall: Aug 16 to Sep 6
Start indoors: Apr 17 to Apr 24Transplant outside: May 29 to Jun 5Sow outdoors: May 22 to Jun 5Plant for fall: Jul 12 to Jul 26
Start indoors: Apr 17 to Apr 24Sow outdoors: May 22 to Jun 5Plant for fall: Jul 19 to Aug 2
Start indoors: Apr 17 to Apr 24Sow outdoors: May 22 to Jun 5
Start indoors: Apr 17 to Apr 24Transplant outside: May 29 to Jun 12
Sow outdoors: Apr 24 to May 22Plant for fall: Jul 5 to Jul 19
Sow outdoors: Apr 24 to May 22Plant for fall: Jul 19 to Aug 2
Sow outdoors: Apr 24 to May 15
Sow outdoors: May 1 to May 29Plant for fall: Jul 19 to Aug 2
Sow outdoors: May 1 to May 22Plant for fall: Aug 2 to Aug 23
Sow outdoors: May 22 to Jun 12Plant for fall: Jul 12 to Jul 26
Sow outdoors: May 22 to Jun 5
Transplant outside: May 29 to Jun 19
Plant for fall: Sep 13 to Oct 18
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Cambridge, ID
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 20 – Mar 6 | Apr 17 – May 1 | — | — |
| Peppers | Mar 6 – Mar 20 | May 29 – Jun 12 | — | — |
| Eggplant | Mar 6 – Mar 20 | May 29 – Jun 12 | — | — |
| Tomatoes | Mar 20 – Apr 3 | May 22 – Jun 5 | — | — |
| Lettuce | Mar 20 – Apr 3 | Apr 24 – May 8 | Apr 17 – May 22 | Aug 2 – Aug 30 |
| Kale | Mar 20 – Apr 3 | Apr 17 – May 1 | Apr 17 – May 1 | Jul 19 – Aug 9 |
| Broccoli | Mar 20 – Apr 3 | May 1 – May 15 | — | Jun 21 – Jul 12 |
| Cabbage | Mar 20 – Apr 3 | Apr 24 – May 8 | — | Jun 21 – Jul 12 |
| Cauliflower | Mar 20 – Apr 3 | May 1 – May 15 | — | Jun 21 – Jul 12 |
| Okra | Apr 3 – Apr 17 | Jun 5 – Jun 19 | Jun 5 – Jun 19 | — |
| Basil | Apr 3 – Apr 17 | May 22 – Jun 5 | — | — |
| Peas | — | — | Apr 3 – Apr 24 | Jul 5 – Jul 26 |
| Spinach | — | — | Apr 3 – Apr 24 | Aug 2 – Aug 23 |
| Radishes | — | — | Apr 10 – May 22 | Aug 16 – Sep 6 |
| Cucumbers | Apr 17 – Apr 24 | May 29 – Jun 5 | May 22 – Jun 5 | Jul 12 – Jul 26 |
| Zucchini & Summer Squash | Apr 17 – Apr 24 | — | May 22 – Jun 5 | Jul 19 – Aug 2 |
| Winter Squash & Pumpkins | Apr 17 – Apr 24 | — | May 22 – Jun 5 | — |
| Melons & Watermelon | Apr 17 – Apr 24 | May 29 – Jun 12 | — | — |
| Carrots | — | — | Apr 24 – May 22 | Jul 5 – Jul 19 |
| Beets | — | — | Apr 24 – May 22 | Jul 19 – Aug 2 |
| Potatoes | — | — | Apr 24 – May 15 | — |
| Swiss Chard | — | — | May 1 – May 29 | Jul 19 – Aug 2 |
| Cilantro | — | — | May 1 – May 22 | Aug 2 – Aug 23 |
| Green Beans | — | — | May 22 – Jun 12 | Jul 12 – Jul 26 |
| Sweet Corn | — | — | May 22 – Jun 5 | — |
| Sweet Potatoes | — | May 29 – Jun 19 | — | — |
| Garlic | — | — | — | Sep 13 – Oct 18 |
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 Cambridge, ID weather station, 2 km away (elevation 2,651 ft (808 m)).
Frost dates near Cambridge
- Midvale May 15 · Sep 27
- Mesa May 10 · Oct 2
- Indian Valley May 15 · Sep 27
- Council May 10 · Oct 2
- Weiser Apr 23 · Oct 13
- Ola May 31 · Sep 16
- Donnelly May 30 · Sep 19
- Lake Fork Jun 22 · Sep 2
- New Meadows frost any month
- McCall Jun 10 · Sep 10
Frequently asked questions
When is the last frost in Cambridge, ID?
The median last spring frost in Cambridge, ID is May 15. There is still about a 10% chance of frost after June 4, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Cambridge, ID?
The median first fall frost is September 27, with about a 10% chance of frost before September 12.
How long is the growing season in Cambridge, ID?
About 135 days between the median last spring frost and first fall frost.
What planting zone is Cambridge, ID?
Cambridge, ID is in USDA hardiness zone 7a.