Last spring frost
Mar 9
Frost Dates for Rock Island, TX
First fall frost
Nov 20
Growing season
255 days
Hardiness zone
9a
In an average year around Rock Island, TX, the last spring frost (32°F) is about Mar 9 and the first fall frost is about Nov 20, giving roughly a 255-day growing season. To be safe most years, wait until Feb 13 before setting out tender plants.
Last spring frost
Dates the last frost of spring typically ends. Plant tender crops after the risk has passed for your comfort level.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | Apr 13 | Mar 23 | Feb 28 |
| Freeze (32°F) | Mar 31 | Mar 9 | Feb 13 |
| Hard (28°F) | Mar 19 | Feb 25 | Jan 22 |
| Severe (24°F) | Mar 9 | Feb 7 | Dec 30 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 13 | Apr 5 | Mar 31 | Mar 27 | Mar 23 | Mar 18 | Mar 13 | Mar 6 | Feb 28 |
| 32°F | Mar 31 | Mar 23 | Mar 18 | Mar 13 | Mar 9 | Mar 4 | Feb 28 | Feb 23 | Feb 13 |
| 28°F | Mar 19 | Mar 12 | Mar 6 | Feb 28 | Feb 25 | Feb 20 | Feb 13 | Feb 1 | Jan 22 |
| 24°F | Mar 9 | Mar 1 | Feb 24 | Feb 17 | Feb 7 | Jan 31 | Jan 24 | Jan 13 | Dec 30 |
| 20°F | Mar 1 | Feb 17 | Feb 4 | Jan 28 | Jan 20 | Jan 13 | Jan 5 | Dec 30 | Dec 15 |
| 16°F | Feb 23 | Feb 6 | Jan 29 | Jan 18 | Jan 11 | Jan 5 | Jan 1 | Dec 26 | Dec 13 |
First fall frost
Dates the first frost of fall typically arrives. Count back by a crop's days-to-maturity to know your planting cutoff.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | Oct 21 | Nov 9 | Dec 2 |
| Freeze (32°F) | Nov 1 | Nov 20 | Dec 13 |
| Hard (28°F) | Nov 6 | Dec 3 | Jan 4 |
| Severe (24°F) | Nov 17 | Dec 20 | Feb 1 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 21 | Oct 29 | Nov 2 | Nov 5 | Nov 9 | Nov 13 | Nov 18 | Nov 25 | Dec 2 |
| 32°F | Nov 1 | Nov 5 | Nov 10 | Nov 15 | Nov 20 | Nov 26 | Dec 1 | Dec 5 | Dec 13 |
| 28°F | Nov 6 | Nov 14 | Nov 22 | Nov 28 | Dec 3 | Dec 8 | Dec 16 | Dec 27 | Jan 4 |
| 24°F | Nov 17 | Nov 27 | Dec 3 | Dec 9 | Dec 20 | Dec 30 | Jan 4 | Jan 10 | Feb 1 |
| 20°F | Nov 28 | Dec 7 | Dec 16 | Dec 25 | Jan 1 | Jan 5 | Jan 11 | Jan 20 | Feb 7 |
| 16°F | Dec 6 | Dec 17 | Dec 26 | Dec 31 | Jan 4 | Jan 10 | Jan 17 | Jan 28 | Feb 6 |
Growing season is measured at 32°F with about 50% probability. Hardiness zone from the 2023 USDA map; frost normals from NOAA 1991-2020.
Where this data comes from
@endif These dates are computed from the nearest official weather station with long-term records: Columbus, Tx, about 11.7 miles away@if(!empty($station['elevation_ft'])), at 225 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.
How we calculate these dates
Frost and freeze dates come from the NOAA 1991–2020 U.S. Climate Normals, the National Oceanic and Atmospheric Administration's 30-year averages for each weather station. A date shown at the 50% level is the median: in half of years the frost falls on or before it. The 10% and 90% columns show the early and late ends of the range, so you can plant on the odds you're comfortable with. These are long-term averages, not a forecast for this year - always check your local outlook before planting.
Source: NOAA National Centers for Environmental Information, 1991–2020 Climate Normals (public domain). Harman is not affiliated with or endorsed by NOAA.
Frequently asked questions
When is the last frost in Rock Island, TX?
On average, the last spring frost (32°F) around Rock Island, TX is about Mar 9. In cooler years it can run later, so for a safer bet many gardeners wait until Feb 13.
When is the first frost in the fall?
The first fall frost around Rock Island, TX typically arrives about Nov 20. Count back by a crop's days to maturity to find the latest date you can plant it.
When can I plant tomatoes and other tender crops?
Tender crops like tomatoes, peppers and basil are damaged by frost, so wait until the last spring frost has passed - around Mar 9 on average, or Feb 13 to be safe most years.
How long is the growing season here?
The frost-free growing season (between the last spring and first fall 32°F frost) is about 255 days in a typical year.
Are these dates a forecast for this year?
No. They are 30-year averages from the NOAA 1991–2020 Climate Normals, not a prediction for the current year. Use them for planning and always check your local weather forecast before planting or protecting crops.
Local weather for 77470 Planting calendar → Texas frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026