Frost dates / Texas / Port Arthur
Frost dates in Port Arthur, TX
The station on this page is PORT ARTHUR SE TX AP, TX US (USW00012917), 8.3 miles from the city point. Population in the Census 2024 estimate is 55,799.
Zone 9bUSDA average annual extreme minimum 25°F to 30°F, from ZIP 77640 (3.1 miles from the city point used on this page).
Outside the median season Growing seasonTicks: 10%, 50%, and 90%
Last 32°F in spring
NCEI’s probability is the chance the last spring minimum of 32°F or lower occurs on or after the date.
| Probability | Date | How to read it |
|---|---|---|
| 90% | January 17 | Earlier date. A last 32°F on or after this day is common. |
| 50% | February 14 | Median. |
| 10% | March 13 | Later date. A last 32°F on or after this day is uncommon. |
First 32°F in fall
NCEI’s probability is the chance the first autumn minimum of 32°F or lower occurs on or before the date.
| Probability | Date | How to read it |
|---|---|---|
| 10% | November 15 | Earlier date. A first 32°F on or before this day is uncommon. |
| 50% | December 7 | Median. |
| 90% | January 9 | Later date. A first 32°F on or before this day is common. |
32°F growing-season length
Days between the last spring 32°F and the first autumn 32°F. The figure is a length the season meets or exceeds at that probability, from NCEI, not a subtraction done on this site.
| Probability the season is at least this long | Days |
|---|---|
| 10% | 338 |
| 50% | 301 |
| 90% | 263 |
28°F threshold
| 10% | 50% | 90% | |
|---|---|---|---|
| Last, on or after | March 3 | January 28 | December 23 |
| First, on or before | December 1 | January 1 | February 3 |
| Season at least | 365 days | 338 days | 300 days |
36°F threshold
| 10% | 50% | 90% | |
|---|---|---|---|
| Last, on or after | March 27 | March 4 | February 5 |
| First, on or before | November 3 | November 23 | December 12 |
| Season at least | 298 days | 264 days | 235 days |
Station PORT ARTHUR SE TX AP, TX US (USW00012917). Completeness flag S, 28 years used for the 32°F dates. NCEI’s annual probability of at least one day at or below 32°F is 98.7%. Freeze dates are conditional on that threshold occurring. Elevation 4.9 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.
Planting calendar for Port Arthur · Zone 9b
Check a crop against this station
Port Arthur, TX
Zone 9bAverage annual extreme minimum 25°F to 30°F
Outside the median season Growing seasonTicks: 10%, 50%, and 90%
Texas. Nearest qualified station: PORT ARTHUR SE TX AP, TX US (USW00012917), 8.3 miles. Median last 32°F February 14. Median first 32°F December 7. The 50% growing-season length is 301 days.
Open the ZIP page · Crop guides for Texas
32°F probabilities at this station
| 10% | 50% | 90% | |
|---|---|---|---|
| Last 32°F on or after | March 13 | February 14 | January 17 |
| First 32°F on or before | November 15 | December 7 | January 9 |
Column order matches the NCEI file: for the last freeze, 10% is the later date and 90% is the earlier date. How to read the probabilities.
Planting calendar
Windows below are from Texas A&M AgriLife Extension, Texas Home Vegetable Gardening Guide, retrieved 2026-10-10. Table 8 is statewide and is written as weeks before or after the frost-free date (spring) and the first freeze date (fall). It is not a single calendar date for every Texas city.
Date checks use your device’s calendar and appear after the page loads.