USDA Hardiness Zone 9a
Frost Dates for 78747 — Austin, Texas
Averages from Austin Bergstrom Ap, Tx US, the nearest reporting station, 6 miles away.
Plant tender crops after March 12, and expect the first autumn freeze around November 16. That leaves about 252 frost-free days.
- Last spring frost
- March 12
- First fall frost
- November 16
- Growing season
- 252 days
- Hardiness zone
- 9a
50% probability
50% probability
frost-free
20 to 25°F annual low
Planting calendar for 78747
| When | What to do |
|---|---|
| January 1 – January 15 | Start peppers and aubergines indoors They need eight to ten weeks under lights before they can go out. |
| January 15 – January 29 | Start tomatoes indoors Six to eight weeks gives a transplant big enough to set fruit early. |
| February 12 – February 26 | Sow peas, spinach, lettuce, radish outdoors These tolerate light frost and prefer to germinate in cool soil. |
| March 12 onward | Transplant tomatoes, peppers, basil, squash, cucumbers The average last freeze has passed — still watch the actual forecast. |
| by August 24 | Sow the autumn crop of carrots, beets and brassicas They need about twelve weeks to size up before growth stops. |
| by November 2 | Harvest tender crops, or be ready to cover them A first freeze two weeks early is well within normal variation. |
| November 16 onward | Plant garlic, mulch beds, lift tender bulbs Garlic wants a cold spell; bare soil loses structure over winter. |
What these dates mean
Wait until after March 12 to put tender plants — tomatoes, peppers, basil, squash — in the ground. That is the date by which half of years in Austin, Texas are past their last freeze. Harvest before November 16, which leaves roughly 252 frost-free days.
ZIP 78747 sits in USDA hardiness zone 9a, meaning the average coldest night of the year falls between 20 to 25°F. Zone decides what survives the winter; frost dates decide when to plant each spring. They are different questions, and a plant can pass one and fail the other.
These are thirty-year NOAA averages for 1991–2020, not a forecast. Any individual year can frost two to three weeks either side of these dates, so check the actual forecast before planting out.