Frost dates for ZIP 77470 (Rock Island, TX)
Average last spring and first fall frost dates with 10%, 50% and 90% odds, from NOAA's 1991–2020 climate normals for the nearest weather station, Columbus, TX (12 miles away).
- Average last spring frostMar 950% chance of a 32°F freeze after this date
- Average first fall frostNov 2050% chance of a 32°F freeze by this date
- Growing season (frost-free)255 daysmedian, 32°F threshold
- USDA hardiness zone9a20 to 25°F avg. coldest night
Last spring frost odds
| Chance of a 32°F freeze after this date | Date |
|---|---|
| 90% (early: most years still freeze after this) | Feb 13 |
| 50% (the "average" last frost) | Mar 9 |
| 10% (safe-side: only 1 year in 10 freezes later) | Mar 31 |
Most gardeners plant frost-tender crops (tomatoes, peppers, basil) after the 50% date, and closer to the 10% date for less risk.
First fall frost odds
| Chance the first 32°F freeze has happened by this date | Date |
|---|---|
| 10% (early: 1 year in 10 freezes this soon) | Nov 1 |
| 50% (the "average" first frost) | Nov 20 |
| 90% (late: most years have frozen by now) | Dec 13 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | Mar 23 | Nov 9 |
| 32°F (freeze) | Mar 9 | Nov 20 |
| 28°F (hard freeze) | Feb 25 | Dec 3 |
n/a means NOAA did not publish a date at that threshold for this station (usually because it rarely gets that cold).
This week in Rock Island
Soil temperature now
2-inch depth
74°F 55°F or warmer
24-hour average · latest 74°F, as of Oct 17, 7:00 PM CDT
Measured at TexMesonet (TWDB) station Wied Ranch, 9 mi away. Daily averages: Thu 80°, Fri 78°.
4-inch depth
74°F 55°F or warmer
24-hour average · latest 74°F, as of Oct 17, 7:00 PM CDT
Measured at TexMesonet (TWDB) station Wied Ranch, 9 mi away. Daily averages: Thu 80°, Fri 78°.
Fall: Texas A&M AgriLife times fall pre-emergent (for winter weeds such as annual bluegrass) to soil cooling to about 70°F for several days. The 50–55°F band is the spring trigger. Always read and follow the product label.
7-day forecast and frost risk
No frost in the 7-day forecast.
| Period | High | Low | Forecast |
|---|---|---|---|
| Tonight | 49° | Partly Cloudy | |
| Sunday | 74° | 53° | Sunny |
| Monday | 79° | 56° | Mostly Sunny |
| Tuesday | 83° | 59° | Sunny |
| Wednesday | 87° | 57° | Sunny |
| Thursday | 88° | 59° | Sunny |
| Friday | 89° | 62° | Sunny |
National Weather Service forecast, issued Oct 17, 8:28 PM CDT. Frost can form above 32°F on clear, calm nights. Full NWS forecast.
Free frost alerts for 77470
An email when the National Weather Service forecasts a freeze for this ZIP, plus the spring soil-temperature heads-up. At most a few a month.
Alerts open soon. This form is a preview and doesn't send anything yet.
Where these numbers come from
Station: Columbus, TX (NOAA GHCN-Daily ID USC00411911), elevation 225 ft, 11.7 miles from the ZIP's center point. NOAA completeness flag: S (standard, 24+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Eagle Lake Resch Ctr, TX | 12 mi | Feb 21 | Dec 1 |
| Hallettsville 2 N, TX | 25 mi | Feb 17 | Dec 4 |
| El Campo, TX | 28 mi | Feb 23 | Dec 5 |
The average last-frost dates of these stations span 23 days, a rough guide to local variation. See data sources & methods.
Questions
When is the last frost in 77470?
The average (50% chance) last spring freeze of 32°F for ZIP 77470 is March 9. For a safer planting date, use March 31, when only 1 year in 10 still sees a later freeze.
When is the first frost in 77470?
The average first fall freeze is November 20. In 1 year in 10 it comes by November 1.
What hardiness zone is 77470?
ZIP 77470 is in USDA zone 9a (20 to 25°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
Other ZIP codes in Colorado County
77412 77434 77442 77460 77475 78933 78934 78935 78943 78951 78962 All Colorado County ZIPs