Frost dates for Portland, AR
At Portland, the median last spring frost (32°F) is Mar 14 and the median first fall frost is Nov 10, for a typical growing season of 241 days. For a 90% chance that the last frost has passed, wait until Apr 1. Nearby ZIP codes are in USDA hardiness zone 8b.
- Mar 14Last spring frost (median)50% chance of 32°F after this date
- Apr 1Safer planting date10% chance of 32°F after this date
- Nov 10First fall frost (median)50% chance of 32°F by this date
- 241 daysGrowing season (median)between 32°F freezes
Last spring frost dates
The chance that the temperature drops to the threshold after each date.
| Temperature | 90% chance later | 50% chance later | 10% chance later |
|---|---|---|---|
| 36°F | Mar 7 | Mar 28 | Apr 14 |
| 32°F | Feb 25 | Mar 14 | Apr 1 |
| 28°F | Feb 9 | Mar 2 | Mar 22 |
| 24°F | Jan 20 | Feb 17 | Mar 11 |
First fall frost dates
The chance that the temperature has dropped to the threshold by each date.
| Temperature | 10% chance by | 50% chance by | 90% chance by |
|---|---|---|---|
| 36°F | Oct 20 | Nov 1 | Nov 18 |
| 32°F | Oct 28 | Nov 10 | Dec 1 |
| 28°F | Nov 4 | Nov 25 | Dec 16 |
| 24°F | Nov 15 | Dec 8 | Jan 9 |
Growing season length
Days between the last spring and first fall freeze, as the length reached in 9, 5 and 1 out of 10 years.
| Temperature | 9 in 10 years at least | 5 in 10 years at least | 1 in 10 years at least |
|---|---|---|---|
| 36°F | 195 days | 218 days | 242 days |
| 32°F | 217 days | 241 days | 266 days |
| 28°F | 236 days | 264 days | 294 days |
| 24°F | 260 days | 294 days | 330 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 99% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 71663 | 8b | 15 to 20°F | 8 km |
| 71658 | 8b | 15 to 20°F | 10 km |
| 71661 | 8b | 15 to 20°F | 12 km |
| 71676 | 8b | 15 to 20°F | 23 km |
| 71250 | 8b | 15 to 20°F | 33 km |
Not the official USDA Plant Hardiness Zone Map. Zones shown here are the values published in the USDA-ARS / Oregon State University PRISM Group 2023 ZIP code tables, shown unaltered. For the official interactive map, visit planthardiness.ars.usda.gov.
About this station
- NOAA station ID USC00035866, at 33.2511, -91.5058, elevation 39 m (128 ft).
- Data quality: Standard (24+ years of data), 26 years of freeze data.
- Average days per year at or below 32°F: 52.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Eudora (27 km)
- Dermott 3 NE (36 km)
- Crossett 2 SSE (44 km)
- Monticello Muni Airport (49 km)
- Rohwer 2 NNE (66 km)
- Warren 2 WSW (68 km)
- Dumas (71 km)
- Cane Creek State Park (78 km)
Sources
- NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020, annual/seasonal normals by station (version 1.0.1), file dated June 27, 2023; documentation.
- USDA Agricultural Research Service and PRISM Group, Oregon State University, 2023 Plant Hardiness Zone Map ZIP code tables (CONUS, Alaska, Hawaii, Puerto Rico), files dated November 17, 2023. Data © PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed November 1, 2026. Official map: planthardiness.ars.usda.gov.
- U.S. Census Bureau, 2024 Gazetteer ZIP Code Tabulation Areas file, dated August 30, 2024 (ZIP centroids used to find the nearest station).
Freeze dates are 30-year probabilities, not forecasts. Check your local forecast before planting tender plants.