Frost dates for 72457Portia, AR
The average last spring frost in Portia is March 27 and the average first fall frost is November 5, giving a typical growing season of about 224 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Mar 27
- Average first fall frost
- Nov 5
- Growing season
- 224 days
Safer after Apr 10 (1-in-10 risk)
Possible by Oct 22 (1-in-10 risk)
First frost typically in 10 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | Mar 21 · Apr 4 · Apr 21 | Oct 15 · Oct 27 · Nov 10 | 204 days | 100% |
| Frost / freeze (32°F) | Mar 10 · Mar 27 · Apr 10 | Oct 22 · Nov 5 · Nov 23 | 224 days | 100% |
| Hard freeze (28°F) | Feb 24 · Mar 13 · Apr 1 | Nov 1 · Nov 17 · Dec 7 | 249 days | 100% |
Planting calendar for Portia
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Feb 24 – May 2 |
| Tomatoes | Transplant outdoors | Apr 12 – Jul 16 |
| Peppers | Start seeds indoors | Feb 24 – Mar 27 |
| Peppers | Transplant outdoors | Apr 26 – May 27 |
| Eggplant | Start seeds indoors | Mar 13 – Apr 11 |
| Eggplant | Transplant outdoors | Apr 26 – May 27 |
| Cucumbers | Sow outdoors | Apr 26 – Jul 26 |
| Summer squash | Sow outdoors | Apr 12 – May 27 |
| Winter squash & pumpkins | Sow outdoors | Apr 26 – May 27 |
| Snap beans | Sow outdoors | Apr 12 – Aug 18 |
| Sweet corn | Sow outdoors | Apr 12 – Jul 16 |
| Watermelon & cantaloupe | Sow outdoors | Apr 26 – May 27 |
| Okra | Sow outdoors | Apr 19 – May 12 |
| Peas | Sow outdoors (spring) | Feb 24 – Apr 11 |
| Potatoes | Plant outdoors (spring) | Feb 24 – Apr 26 |
| Onions | Start seeds indoors (spring) | Jan 13 – Feb 9 |
| Onions | Transplant outdoors (spring) | Mar 13 – Apr 11 |
| Broccoli | Start seeds indoors (spring) | Feb 6 – Mar 12 |
| Broccoli | Transplant outdoors (spring) | Mar 13 – Apr 11 |
| Broccoli | Start seeds indoors (fall) | Jul 6 – Jul 16 |
| Broccoli | Transplant outdoors (fall) | Aug 5 – Aug 16 |
| Cabbage | Start seeds indoors (spring) | Jan 27 – Feb 24 |
| Cabbage | Transplant outdoors (spring) | Feb 24 – Mar 27 |
| Cabbage | Start seeds indoors (fall) | Jun 26 – Jul 26 |
| Cabbage | Transplant outdoors (fall) | Jul 26 – Aug 26 |
| Leaf lettuce | Sow outdoors (spring) | Feb 24 – May 12 |
| Leaf lettuce | Sow outdoors (fall) | Jul 26 – Sep 11 |
| Spinach | Sow outdoors (spring) | Feb 17 – Apr 2 |
| Spinach | Sow outdoors (fall) | Aug 12 – Sep 16 |
| Radishes | Sow outdoors (spring) | Feb 24 – Apr 16 |
| Radishes | Sow outdoors (fall) | Jul 26 – Sep 26 |
| Kale | Sow outdoors (spring) | Mar 13 – Apr 2 |
| Kale | Sow outdoors (fall) | Jul 19 – Aug 26 |
| Carrots | Sow outdoors (spring) | Mar 27 – May 12 |
| Carrots | Sow outdoors (fall) | Jun 26 – Aug 11 |
| Garlic | Plant outdoors (fall) | Oct 26 – Nov 26 |
Where these dates come from
ZIP code 72457 is matched to the NOAA station Alicia 2Nne, AR, 17.3 km away, at 258 ft elevation (5 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Alicia 2Nne, AR (used) | 258 ft | Mar 27 | Nov 5 |
| Pocahontas 1, AR | 315 ft | Mar 31 | Nov 1 |
| Hardy, AR | 400 ft | Apr 4 | Oct 31 |
| Jonesboro 2 Ne, AR | 310 ft | Apr 1 | Nov 1 |
Frost dates near Portia
- Black Rock, AR 72415 · last Mar 31, first Nov 1
- Powhatan, AR 72458 · last Mar 27, first Nov 5
- Hoxie, AR 72433 · last Mar 27, first Nov 5
- Minturn, AR 72445 · last Mar 27, first Nov 5
- Walnut Ridge, AR 72476 · last Mar 27, first Nov 5
- Alicia, AR 72410 · last Mar 27, first Nov 5
- Imboden, AR 72434 · last Mar 31, first Nov 1
- Smithville, AR 72466 · last Apr 14, first Oct 20
Frequently asked questions
- When is the last frost in Portia, AR?
- For ZIP code 72457, the average last spring frost (32°F) is March 27, based on NOAA 1991-2020 climate normals for the Alicia 2Nne, AR weather station. There is a 1-in-10 chance of a frost after April 10.
- When is the first frost in Portia, AR?
- The average first fall frost (32°F) is November 5. There is a 1-in-10 chance of frost by October 22, so tender plants are at risk from that point on.
- How long is the growing season in 72457?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 224 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.