Irmo, SC frost dates
Last spring frostApr 10median date
First fall frostOct 28median date
Growing season201 daysfrost-free
Hardiness zone8bZone 8b
How Irmo compares
- In 8 years out of 10, the last spring frost in Irmo falls between March 27 and April 23, a 27-day window. The first fall frost falls between October 15 and November 8.
- The median last frost is 16 days later than the South Carolina median of Mar 25.
- Its 201-day growing season is longer than 3% of the 375 South Carolina places with a regular frost season (state median 228 days).
- The last frost is 25 days later than the zone 8b median of Mar 16. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 8b chart.
- The weather station records an average of 95 nights a year at or below 32°F.
- Compared with Columbia, SC, 20 km away, the last frost here is 25 days later than there and the growing season is 44 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | March 27 |
| 50% (median) | April 10 |
| 10% (safe for tender plants) | April 23 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 15 |
| 50% (median) | October 28 |
| 90% (late) | November 8 |
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 Irmo, SC
Irmo, SC frost dates — last frost Apr 10, first frost Oct 28, zone 8b. whenisthelastfrost.com
Crop
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Start indoors: Jan 16 to Jan 30Transplant outside: Mar 13 to Mar 27
Start indoors: Jan 30 to Feb 13Transplant outside: Apr 24 to May 8
Start indoors: Jan 30 to Feb 13Transplant outside: Apr 24 to May 8
Start indoors: Feb 13 to Feb 27Transplant outside: Apr 17 to May 1
Start indoors: Feb 13 to Feb 27Transplant outside: Mar 20 to Apr 3Sow outdoors: Mar 13 to Apr 17Plant for fall: Sep 2 to Sep 30
Start indoors: Feb 13 to Feb 27Transplant outside: Mar 13 to Mar 27Sow outdoors: Mar 13 to Mar 27Plant for fall: Aug 19 to Sep 9
Start indoors: Feb 13 to Feb 27Transplant outside: Mar 27 to Apr 10Plant for fall: Jul 22 to Aug 12
Start indoors: Feb 13 to Feb 27Transplant outside: Mar 20 to Apr 3Plant for fall: Jul 22 to Aug 12
Start indoors: Feb 13 to Feb 27Transplant outside: Mar 27 to Apr 10Plant for fall: Jul 22 to Aug 12
Start indoors: Feb 27 to Mar 13Transplant outside: May 1 to May 15Sow outdoors: May 1 to May 15
Start indoors: Feb 27 to Mar 13Transplant outside: Apr 17 to May 1
Sow outdoors: Feb 27 to Mar 20Plant for fall: Aug 5 to Aug 26
Sow outdoors: Feb 27 to Mar 20Plant for fall: Sep 2 to Sep 23
Sow outdoors: Mar 6 to Apr 17Plant for fall: Sep 16 to Oct 7
Start indoors: Mar 13 to Mar 20Transplant outside: Apr 24 to May 1Sow outdoors: Apr 17 to May 1Plant for fall: Aug 12 to Aug 26
Start indoors: Mar 13 to Mar 20Sow outdoors: Apr 17 to May 1Plant for fall: Aug 19 to Sep 2
Start indoors: Mar 13 to Mar 20Sow outdoors: Apr 17 to May 1
Start indoors: Mar 13 to Mar 20Transplant outside: Apr 24 to May 8
Sow outdoors: Mar 20 to Apr 17Plant for fall: Aug 5 to Aug 19
Sow outdoors: Mar 20 to Apr 17Plant for fall: Aug 19 to Sep 2
Sow outdoors: Mar 20 to Apr 10
Sow outdoors: Mar 27 to Apr 24Plant for fall: Aug 19 to Sep 2
Sow outdoors: Mar 27 to Apr 17Plant for fall: Sep 2 to Sep 23
Sow outdoors: Apr 17 to May 8Plant for fall: Aug 12 to Aug 26
Sow outdoors: Apr 17 to May 1
Transplant outside: Apr 24 to May 15
Plant for fall: Oct 14 to Nov 18
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Irmo, SC
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 16 – Jan 30 | Mar 13 – Mar 27 | — | — |
| Peppers | Jan 30 – Feb 13 | Apr 24 – May 8 | — | — |
| Eggplant | Jan 30 – Feb 13 | Apr 24 – May 8 | — | — |
| Tomatoes | Feb 13 – Feb 27 | Apr 17 – May 1 | — | — |
| Lettuce | Feb 13 – Feb 27 | Mar 20 – Apr 3 | Mar 13 – Apr 17 | Sep 2 – Sep 30 |
| Kale | Feb 13 – Feb 27 | Mar 13 – Mar 27 | Mar 13 – Mar 27 | Aug 19 – Sep 9 |
| Broccoli | Feb 13 – Feb 27 | Mar 27 – Apr 10 | — | Jul 22 – Aug 12 |
| Cabbage | Feb 13 – Feb 27 | Mar 20 – Apr 3 | — | Jul 22 – Aug 12 |
| Cauliflower | Feb 13 – Feb 27 | Mar 27 – Apr 10 | — | Jul 22 – Aug 12 |
| Okra | Feb 27 – Mar 13 | May 1 – May 15 | May 1 – May 15 | — |
| Basil | Feb 27 – Mar 13 | Apr 17 – May 1 | — | — |
| Peas | — | — | Feb 27 – Mar 20 | Aug 5 – Aug 26 |
| Spinach | — | — | Feb 27 – Mar 20 | Sep 2 – Sep 23 |
| Radishes | — | — | Mar 6 – Apr 17 | Sep 16 – Oct 7 |
| Cucumbers | Mar 13 – Mar 20 | Apr 24 – May 1 | Apr 17 – May 1 | Aug 12 – Aug 26 |
| Zucchini & Summer Squash | Mar 13 – Mar 20 | — | Apr 17 – May 1 | Aug 19 – Sep 2 |
| Winter Squash & Pumpkins | Mar 13 – Mar 20 | — | Apr 17 – May 1 | — |
| Melons & Watermelon | Mar 13 – Mar 20 | Apr 24 – May 8 | — | — |
| Carrots | — | — | Mar 20 – Apr 17 | Aug 5 – Aug 19 |
| Beets | — | — | Mar 20 – Apr 17 | Aug 19 – Sep 2 |
| Potatoes | — | — | Mar 20 – Apr 10 | — |
| Swiss Chard | — | — | Mar 27 – Apr 24 | Aug 19 – Sep 2 |
| Cilantro | — | — | Mar 27 – Apr 17 | Sep 2 – Sep 23 |
| Green Beans | — | — | Apr 17 – May 8 | Aug 12 – Aug 26 |
| Sweet Corn | — | — | Apr 17 – May 1 | — |
| Sweet Potatoes | — | Apr 24 – May 15 | — | — |
| Garlic | — | — | — | Oct 14 – Nov 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 Cedar Creek 2e, SC weather station, 16 km away (elevation 338 ft (103 m)).
Frost dates near Irmo
- Ballentine Apr 10 · Oct 28
- White Rock Mar 22 · Nov 11
- Chapin Mar 22 · Nov 11
- Peak Mar 22 · Nov 11
- West Columbia Mar 25 · Nov 7
- Jenkinsville Mar 22 · Nov 11
- Lexington Mar 25 · Nov 7
- Cayce Mar 25 · Nov 7
- Columbia Mar 16 · Nov 16
- Little Mountain Mar 22 · Nov 11
Frequently asked questions
When is the last frost in Irmo, SC?
The median last spring frost in Irmo, SC is April 10. There is still about a 10% chance of frost after April 23, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Irmo, SC?
The median first fall frost is October 28, with about a 10% chance of frost before October 15.
How long is the growing season in Irmo, SC?
About 201 days between the median last spring frost and first fall frost.
What planting zone is Irmo, SC?
Irmo, SC is in USDA hardiness zone 8b.