Fall in zone 9aPhoto: George Chernilevsky, Public domain, via Wikimedia Commons
Frost dates for ZIP 78665 (Round Rock, 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, Georgetown Lake, TX (10 miles away).
- Average last spring frostMar 650% chance of a 32°F freeze after this date
- Average first fall frostNov 2450% chance of a 32°F freeze by this date
- Growing season (frost-free)259 daysmedian, 32°F threshold
- USDA hardiness zone9a20 to 25°F avg. coldest night
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This week in your yard
As of Oct 18, 2026, from your frost dates, zone and soil temperature. Lawn timing · Vegetables · Pruning · Plants
Soil temperature now
2-inch depth
70°F 55°F or warmer
24-hour average · latest 70°F, as of Oct 18, 1:00 AM CDT
Measured at TexMesonet (TWDB) station Texas State University Round Rock, 1 mi away. Daily averages: Thu 83°, Fri 76°, Sat 70°.
4-inch depth
72°F 55°F or warmer
24-hour average · latest 73°F, as of Oct 18, 1:00 AM CDT
Measured at TexMesonet (TWDB) station Texas State University Round Rock, 1 mi away. Daily averages: Thu 83°, Fri 78°, Sat 72°.
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
The latest National Weather Service 7-day forecast and any Frost Advisory or Freeze Warning for 78665 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
Soil is 72°F at 4 inches. Fall pre-emergent (annual bluegrass, winter weeds): window open as soil cools through the 70s and 60s.
Fertilizer window
Lawn region: South Central plains. Timing only; always follow the product label.
- Bermudagrass (warm-season): Spring: Several weeks after the lawn is fully green (April–May) (about Apr 21 here, using green-up about 3–4 weeks after your average last frost); Summer: Every 4–6 weeks through mid-August (heaviest feeder of the group); Late: Light, low-nitrogen/high-potassium feeding about 4 weeks before first frost, or skip. Avoid: Heavy late-fall nitrogen (linked to spring dead spot).
- Tall fescue (cool-season): Early fall: September (main feeding); Late fall: November, while still green; Late winter: Optional light feeding February–March. Avoid: Feeding after mid-spring and through summer in the transition zone (stress and brown patch).
Plant now
- Lettuce: fall transplant Sep 29–Oct 20
- Spinach: fall sowing Sep 29–Oct 20
- Arugula: fall sowing Sep 29–Oct 27
- Radish: fall sowing Oct 13–27
- Garlic: fall sowing Oct 13–Nov 10
- Shallot: fall sowing Oct 13–Nov 10
Prune now
No frost-timed pruning windows are open this week.
Your average first frost is Nov 24: skip heavy pruning in the 6–8 weeks before it, because new growth may not harden off in time.
Spring-flowering shrubs are pruned right after their flowers fade, not by date. See the pruning guide.
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 6 |
| 10% (cautious: only 1 year in 10 freezes later) | Mar 30 |
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 5 |
| 50% (the "average" first frost) | Nov 24 |
| 90% (late: most years have frozen by now) | Dec 10 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | Mar 22 | Nov 13 |
| 32°F (freeze) | Mar 6 | Nov 24 |
| 28°F (hard freeze) | Feb 23 | Dec 5 |
n/a means NOAA did not publish a date at that threshold for this station (usually because it rarely gets that cold).
Vegetable planting calendar for 78665
Dates count from your average last spring frost (Mar 6) and first fall frost (Nov 24). Half of years have a frost after the spring date, so give tender crops (tomatoes, peppers, squash) some slack.
| Crop | Start indoors | Spring planting | Fall planting |
|---|---|---|---|
| Tomato | Jan 9–23 | Mar 13–27 (transplant) | Jul 28–Aug 25 (transplant) |
| Pepper (sweet and hot) | Dec 26–Jan 9 | Mar 20–Apr 3 (transplant) | Aug 4–25 (transplant) |
| Eggplant | Dec 26–Jan 9 | Mar 20–Apr 3 (transplant) | Aug 4–25 (transplant) |
| Tomatillo | Jan 9–23 | Mar 13–27 (transplant) | – |
| Lettuce | Jan 9–23 | Feb 13–Mar 6 (transplant) Feb 6–Mar 20 (sow outdoors) | Sep 29–Oct 20 (transplant) Sep 15–Oct 13 (sowing) |
| Spinach | – | Jan 23–Feb 13 (sow outdoors) | Sep 29–Oct 20 (sowing) |
| Kale | Jan 9–23 | Feb 6–20 (transplant) Feb 6–20 (sow outdoors) | Sep 1–29 (transplant) Aug 18–Sep 15 (sowing) |
| Collards | Jan 9–23 | Feb 6–Mar 6 (transplant) Feb 6–Mar 6 (sow outdoors) | Sep 1–29 (transplant) Aug 18–Sep 15 (sowing) |
| Broccoli | Dec 26–Jan 9 | Feb 6–20 (transplant) | Aug 18–Sep 15 (transplant) |
| Cabbage | Dec 26–Jan 9 | Feb 6–20 (transplant) | Aug 18–Sep 15 (transplant) |
| Cauliflower | Dec 26–Jan 9 | Feb 20–Mar 6 (transplant) | Aug 18–Sep 15 (transplant) |
| Brussels sprouts | Dec 12–26 | Feb 6–20 (transplant) | Aug 4–25 (transplant) |
| Kohlrabi | Jan 9–23 | Feb 6–20 (transplant) Feb 6–20 (sow outdoors) | Sep 15–29 (sowing) |
| Bok choy / Asian greens | – | Feb 6–20 (sow outdoors) | Sep 29–Oct 13 (sowing) |
| Arugula | – | Feb 6–Mar 6 (sow outdoors) | Sep 29–Oct 27 (sowing) |
| Mustard greens | – | Feb 6–27 (sow outdoors) | Sep 29–Oct 13 (sowing) |
| Swiss chard | Jan 23–Feb 6 | Feb 20–Mar 13 (transplant) Feb 20–Mar 20 (sow outdoors) | Sep 15–29 (sowing) |
| Beet | – | Feb 6–Mar 6 (sow outdoors) | Sep 15–29 (sowing) |
| Carrot | – | Feb 13–Mar 13 (sow outdoors) | Sep 1–15 (sowing) |
| Radish | – | Jan 30–Mar 13 (sow outdoors) | Oct 13–27 (sowing) |
| Turnip | – | Feb 6–27 (sow outdoors) | Sep 15–29 (sowing) |
| Parsnip | – | Feb 13–Mar 6 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Jan 9–Feb 6 (sow outdoors) | Sep 1–15 (sowing) |
| Onion (bulbing) | Dec 12–26 | Jan 23–Feb 6 (transplant) | – |
| Green onion / scallion | – | Jan 23–Feb 20 (sow outdoors) | Sep 15–29 (sowing) |
| Leek | Dec 12–26 | Feb 6–20 (transplant) | – |
| Garlic | – | – | Oct 13–Nov 10 (sowing) |
| Shallot | – | Jan 23–Feb 6 (transplant) | Oct 13–Nov 10 (sowing) |
| Potato | – | Feb 6–20 (transplant) | Aug 4–18 (transplant) |
| Sweet potato | – | Mar 27–Apr 10 (transplant) | – |
| Sweet corn | – | Mar 13–27 (sow outdoors) | – |
| Bean, bush (snap) | – | Mar 13–27 (sow outdoors) | Sep 1–15 (sowing) |
| Bean, pole | – | Mar 13–27 (sow outdoors) | – |
| Lima bean | – | Mar 20–Apr 3 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Mar 27–Apr 17 (sow outdoors) | – |
| Cucumber | Feb 6–13 | Mar 13–27 (transplant) Mar 13–27 (sow outdoors) | Sep 1–15 (sowing) |
| Summer squash / zucchini | Feb 6–13 | Mar 13–27 (transplant) Mar 13–27 (sow outdoors) | Sep 1–15 (sowing) |
| Winter squash | Feb 6–13 | Mar 13–27 (transplant) Mar 13–27 (sow outdoors) | – |
| Pumpkin | – | Mar 13–27 (sow outdoors) | – |
| Watermelon | Feb 6–13 | Mar 20–Apr 3 (transplant) Mar 20–Apr 3 (sow outdoors) | – |
| Cantaloupe / muskmelon | Feb 6–13 | Mar 20–Apr 3 (transplant) Mar 20–Apr 3 (sow outdoors) | – |
| Okra | Jan 23–Feb 6 | Mar 20–Apr 3 (transplant) Mar 20–Apr 3 (sow outdoors) | – |
| Celery | Dec 12–26 | Mar 13–20 (transplant) | – |
| Basil | Jan 23–Feb 6 | Mar 13–27 (transplant) Mar 13–27 (sow outdoors) | – |
| Cilantro | – | Feb 20–Mar 20 (sow outdoors) | Sep 29–Oct 13 (sowing) |
| Parsley | Dec 26–Jan 9 | Feb 20–Mar 6 (transplant) Feb 13–Mar 6 (sow outdoors) | – |
| Dill | – | Mar 6–20 (sow outdoors) | Sep 29–Oct 13 (sowing) |
| Sunflower | – | Mar 6–20 (sow outdoors) | – |
| Asparagus (crowns) | – | Feb 6–20 (transplant) | – |
| Rhubarb (crowns) | – | Feb 6–20 (transplant) | – |
| Strawberry (plants) | – | Feb 6–20 (transplant) | Sep 15–Oct 13 (transplant) |
Typical ranges from university extension planting calendars, adjusted to your frost dates. Probabilities, not guarantees. Fall windows that would overlap spring planting are left out, as are fall crops of frost-tender plants where the frost-free season is under 210 days.
Plants that do well here
Texas A&M AgriLife trials name plants that handle Texas conditions: the Texas Superstar® list and the low-care roses from AgriLife trials. Plant frost-tender annuals after March 6 here (the average last frost). More on plants for Texas. Not affiliated with Texas A&M AgriLife.
Where these numbers come from
Station: Georgetown Lake, TX (NOAA GHCN-Daily ID USC00413507), elevation 874 ft, 10.1 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Austin Great Hills, TX | 12 mi | Mar 11 | Nov 20 |
| Taylor 1NW, TX | 13 mi | Mar 8 | Nov 21 |
| Austin-camp Mabry, TX | 17 mi | Feb 20 | Dec 3 |
The average last-frost dates of these stations span 22 days, a rough guide to local variation. See data sources & methods.
Frost questions for 78665
When is the last frost in 78665?
The average (50% chance) last spring freeze of 32°F for ZIP 78665 is March 6. For a more cautious planting date, use March 30, when only 1 year in 10 still sees a later freeze.
When is the first frost in 78665?
The average first fall freeze is November 24. In 1 year in 10 it comes by November 5.
What hardiness zone is 78665?
ZIP 78665 is in USDA zone 9a (20 to 25°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 78665 right now?
This page shows the latest 2-inch and 4-inch soil temperature from the nearest public soil station (USDA SCAN, NOAA USCRN or TexMesonet), or a labeled estimate when no station is close, against the 50–55°F spring pre-emergent band.
Nearby ZIP codes
78664 Round Rock 78681 Round Rock 78634 Hutto 78728 Austin 78626 Georgetown 78660 Pflugerville 78717 Austin 78674 Weir
Other ZIP codes in Williamson County
76527 76530 76537 76573 76574 76578 78613 78615 78626 78628 78633 78634 78642 78664 78674 78681 78717 78729 All Williamson County frost dates · Texas frost dates
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- Freeze alerts
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Free. One weekly email plus alerts when your ZIP has a frost or a soil-temperature change worth acting on. After you submit, Kit (our email provider) sends a confirmation email: check your email and click the link to confirm. You aren't subscribed until you do. We collect only your email address and ZIP, sent to Kit to deliver The Dial. Unsubscribe anytime.