USDA Hardiness Zone 9a
Frost Dates for 77964 — Hallettsville, Texas
NOAA 1991–2020 normals from Hallettsville 2 N, TX (275 ft), 8 miles northwest.
Updated
In Hallettsville, the last spring frost (32°F) is around February 17 in half of years and has passed by March 13 in nine years out of ten. The first fall frost comes around December 4, as early as November 14 one year in ten, leaving a typical freeze-free season of 297 days (NOAA, Hallettsville 2 N, TX).
- Last spring frost
- February 17
- First fall frost
- December 4
- Growing season
- 297 days
- Hardiness zone
- 9a
50% probability
50% probability
freeze-free, 50%
20 to 25°F (-6.7 to -3.9°C) coldest night
- First snow
- Rare
- Last snow
- Rare
- Winters with snow
- 8%
- Snow per year
- 0.1"
median, 1991–2020
median, 1991–2020
2 of 25 observed
NOAA normal
Frost risk by date in Hallettsville
Half of springs at Hallettsville 2 N, TX see their last 32°F night by February 17; only one in ten is past it by January 19, and one in ten still has one after March 13. Planting tender crops after February 28 leaves a 30% risk of a frost on them, after March 5 20%, and after March 13 10%. The 24 days between the even-odds date and the one-in-ten date is wider than at 76% of the 339 Texas stations behind this site's ZIP pages, so a fixed calendar date is a gamble here.
In fall the first 32°F night comes by December 4 in half of years, as early as November 14 one year in ten, and holds off past January 8 one year in ten. A hard freeze of 28°F follows 23 days later, around December 27; in spring the one-in-ten date for 28°F is February 28, 13 days before the 32°F one. The freeze-free season lasts 297 days in a typical year, longer than at 86% of the 339 Texas stations; it reaches 332 days one year in ten and falls short of 262 one year in ten. On average 13 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 16 days longer, to about March 5, and return around November 23. A 24°F night is unusual: 44% of winters had one.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Feb 9 | Feb 19 | Feb 24 | Mar 1 | Mar 5 | Mar 9 | Mar 13 | Mar 21 | Mar 29 |
| 32°F | Jan 19 | Jan 28 | Feb 3 | Feb 10 | Feb 17 | Feb 23 | Feb 28 | Mar 5 | Mar 13 |
| 28°F86% of yrs | Dec 24 | Jan 7 | Jan 17 | Jan 24 | Jan 30 | Feb 4 | Feb 12 | Feb 19 | Feb 28 |
| 24°F44% of yrs | too rare for a date | ||||||||
| 20°F13% of yrs | too rare for a date | ||||||||
| 16°F1% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Nov 4 | Nov 10 | Nov 14 | Nov 18 | Nov 23 | Nov 27 | Dec 1 | Dec 4 | Dec 12 |
| 32°F | Nov 14 | Nov 21 | Nov 26 | Dec 1 | Dec 4 | Dec 9 | Dec 17 | Dec 29 | Jan 8 |
| 28°F86% of yrs | Nov 28 | Dec 5 | Dec 10 | Dec 18 | Dec 27 | Jan 2 | Jan 10 | Jan 19 | Feb 3 |
| 24°F44% of yrs | too rare for a date | ||||||||
| 20°F13% of yrs | too rare for a date | ||||||||
| 16°F1% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Hallettsville 2 N, TX, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.
Frost risk on any date in 77964 →Compare Hallettsville with another place →
Weather by month in Hallettsville
August is the warmest month at Hallettsville 2 N, TX, averaging 98°F by day and 75°F at night; January is the coldest at 66°F and 45°F. From April to October the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 63% of years and March still brings one in 28% of years.
Warmth for growing adds up to 8,090 growing degree days a year (base 50°F), more than at 90% of the 351 Texas stations. 43% of them (3,506) have built up by the end of June, and August adds the most, 1,125. Precipitation totals 40.5 inches a year, most in June (4.5") and least in February (2.3"); May to September bring 45% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 66 | 45 | 3.1 | 84% | 5 | 219 |
| Feb | 69 | 49 | 2.3 | 63% | 2 | 278 |
| Mar | 76 | 55 | 3.0 | 28% | 1 | 479 |
| Apr | 82 | 61 | 3.5 | 1% | 0 | 641 |
| May | 88 | 69 | 4.4 | 0% | 0 | 880 |
| Jun | 94 | 74 | 4.5 | 0% | 0 | 1009 |
| Jul | 96 | 75 | 2.5 | 0% | 0 | 1110 |
| Aug | 98 | 75 | 3.2 | 0% | 0 | 1125 |
| Sep | 92 | 71 | 3.7 | 0% | 0 | 951 |
| Oct | 85 | 62 | 4.3 | 1% | 0 | 734 |
| Nov | 75 | 53 | 3.3 | 38% | 1 | 421 |
| Dec | 67 | 46 | 2.7 | 71% | 4 | 244 |
Monthly normals 1991–2020 at Hallettsville 2 N, TX (275 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.
Compared with the next station
The nearest other station, Yoakum, TX, 19 miles west of Hallettsville, has a last frost 13 days later (March 2), a first frost 4 days earlier (November 30), a season 21 days shorter.
When it snows in Hallettsville, Texas
Measurable snow is rare here: only 2 of 25 winters from 1991 to 2020 recorded 0.1 inch or more at Hallettsville 2 N, TX, 8.3 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 77964
| When | What to do |
|---|---|
| December 9 – December 23 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| December 23 – January 6 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| January 20 – February 3 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| February 17 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by September 11 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by November 20 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| December 4 onward | Plant garlic, mulch beds, lift tender bulbsGarlic wants a cold spell; bare soil loses structure over winter. |
The weeks before and after the 50% dates are general rules of thumb, not NOAA figures; a seed packet gives the timing for each variety.
Where these figures come from
ZIP 77964 is 8 miles from Hallettsville 2 N, TX, which stands at 275 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 77964 in zone 9a, the band where the coldest night of the year averaged 20 to 25°F (-6.7 to -3.9°C) over 1991–2020; a zone describes winter lows, not frost dates.
Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.
Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.