Parma, ID frost dates
How Parma compares
- In 8 years out of 10, the last spring frost in Parma falls between April 13 and May 9, a 26-day window. The first fall frost falls between September 26 and October 26.
- The median last frost is 17 days earlier than the Idaho median of May 14.
- Its 165-day growing season is longer than 83% of the 244 Idaho places with a regular frost season (state median 138 days).
- The last frost is 11 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 144 nights a year at or below 32°F.
- Compared with Caldwell, ID, 20 km away, the last frost here is 4 days later than there and the growing season is 13 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 13 |
| 50% (median) | April 27 |
| 10% (safe for tender plants) | May 9 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 26 |
| 50% (median) | October 9 |
| 90% (late) | October 26 |
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 Parma, ID
Parma, ID frost dates — last frost Apr 27, first frost Oct 9, zone 7a. whenisthelastfrost.com
When to plant vegetables in Parma, ID
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 2 – Feb 16 | Mar 30 – Apr 13 | — | — |
| Peppers | Feb 16 – Mar 2 | May 11 – May 25 | — | — |
| Eggplant | Feb 16 – Mar 2 | May 11 – May 25 | — | — |
| Tomatoes | Mar 2 – Mar 16 | May 4 – May 18 | — | — |
| Lettuce | Mar 2 – Mar 16 | Apr 6 – Apr 20 | Mar 30 – May 4 | Aug 14 – Sep 11 |
| Kale | Mar 2 – Mar 16 | Mar 30 – Apr 13 | Mar 30 – Apr 13 | Jul 31 – Aug 21 |
| Broccoli | Mar 2 – Mar 16 | Apr 13 – Apr 27 | — | Jul 3 – Jul 24 |
| Cabbage | Mar 2 – Mar 16 | Apr 6 – Apr 20 | — | Jul 3 – Jul 24 |
| Cauliflower | Mar 2 – Mar 16 | Apr 13 – Apr 27 | — | Jul 3 – Jul 24 |
| Okra | Mar 16 – Mar 30 | May 18 – Jun 1 | May 18 – Jun 1 | — |
| Basil | Mar 16 – Mar 30 | May 4 – May 18 | — | — |
| Peas | — | — | Mar 16 – Apr 6 | Jul 17 – Aug 7 |
| Spinach | — | — | Mar 16 – Apr 6 | Aug 14 – Sep 4 |
| Radishes | — | — | Mar 23 – May 4 | Aug 28 – Sep 18 |
| Cucumbers | Mar 30 – Apr 6 | May 11 – May 18 | May 4 – May 18 | Jul 24 – Aug 7 |
| Zucchini & Summer Squash | Mar 30 – Apr 6 | — | May 4 – May 18 | Jul 31 – Aug 14 |
| Winter Squash & Pumpkins | Mar 30 – Apr 6 | — | May 4 – May 18 | — |
| Melons & Watermelon | Mar 30 – Apr 6 | May 11 – May 25 | — | — |
| Carrots | — | — | Apr 6 – May 4 | Jul 17 – Jul 31 |
| Beets | — | — | Apr 6 – May 4 | Jul 31 – Aug 14 |
| Potatoes | — | — | Apr 6 – Apr 27 | — |
| Swiss Chard | — | — | Apr 13 – May 11 | Jul 31 – Aug 14 |
| Cilantro | — | — | Apr 13 – May 4 | Aug 14 – Sep 4 |
| Green Beans | — | — | May 4 – May 25 | Jul 24 – Aug 7 |
| Sweet Corn | — | — | May 4 – May 18 | — |
| Sweet Potatoes | — | May 11 – Jun 1 | — | — |
| Garlic | — | — | — | Sep 25 – Oct 30 |
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 Parma Exp Stn, ID weather station, about 1 km away (elevation 2,290 ft (698 m)).
Frost dates near Parma
- Notus Apr 27 · Oct 9
- Wilder Apr 24 · Oct 9
- Greenleaf Apr 24 · Oct 9
- Homedale Apr 24 · Oct 9
- Caldwell Apr 23 · Oct 18
- New Plymouth Apr 22 · Oct 9
- Fruitland Apr 22 · Oct 9
- Huston Apr 23 · Oct 18
- Letha Apr 30 · Oct 17
- Middleton Apr 29 · Oct 13
Frequently asked questions
When is the last frost in Parma, ID?
The median last spring frost in Parma, ID is April 27. There is still about a 10% chance of frost after May 9, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Parma, ID?
The median first fall frost is October 9, with about a 10% chance of frost before September 26.
How long is the growing season in Parma, ID?
About 165 days between the median last spring frost and first fall frost.
What planting zone is Parma, ID?
Parma, ID is in USDA hardiness zone 7a.