USDA Hardiness Zone 9b
Frost Dates for 77979 — Port Lavaca, Texas
NOAA 1991–2020 normals from Pt Comfort, TX (20 ft), 6 miles northeast.
Updated
In Port Lavaca, the last spring frost (32°F) is around February 1 in half of years and has passed by March 4 in nine years out of ten. The first fall frost comes around December 21, as early as November 25 one year in ten, leaving a typical freeze-free season of 321 days (NOAA, Pt Comfort, TX).
- Last spring frost
- February 1
- First fall frost
- December 21
- Growing season
- 321 days
- Hardiness zone
- 9b
50% probability
50% probability
freeze-free, 50%
25 to 30°F (-3.9 to -1.1°C) coldest night
- First snow
- Rare
- Last snow
- Rare
- Winters with snow
- 0%
- Snow per year
- 0"
median, 1991–2020
median, 1991–2020
0 of 28 observed
NOAA normal
Frost risk by date in Port Lavaca
Half of springs at Pt Comfort, TX see their last 32°F night by February 1; only one in ten is past it by December 24, and one in ten still has one after March 4. Planting tender crops after February 16 leaves a 30% risk of a frost on them, after February 24 20%, and after March 4 10%. The 31 days between the even-odds date and the one-in-ten date is wider than at 92% 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 21 in half of years, as early as November 25 one year in ten, and holds off past January 18 one year in ten. A hard freeze of 28°F follows 11 days later, around January 1; in spring the one-in-ten date for 28°F is February 23, 9 days before the 32°F one. The freeze-free season lasts 321 days in a typical year, longer than at 92% of the 339 Texas stations; it reaches 361 days one year in ten and falls short of 280 one year in ten. On average 5 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 21 days longer, to about February 22, and return around December 3. A 24°F night is unusual: 20% of winters had one.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jan 25 | Feb 1 | Feb 8 | Feb 16 | Feb 22 | Feb 27 | Mar 4 | Mar 10 | Mar 18 |
| 32°F93% of yrs | Dec 24 | Jan 8 | Jan 19 | Jan 26 | Feb 1 | Feb 6 | Feb 16 | Feb 24 | Mar 4 |
| 28°F58% of yrs | Dec 17 | Dec 28 | Jan 4 | Jan 14 | Jan 21 | Jan 27 | Feb 1 | Feb 9 | Feb 23 |
| 24°F20% of yrs | too rare for a date | ||||||||
| 20°F3% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Nov 10 | Nov 18 | Nov 24 | Nov 28 | Dec 3 | Dec 7 | Dec 12 | Dec 19 | Dec 28 |
| 32°F93% of yrs | Nov 25 | Dec 3 | Dec 9 | Dec 15 | Dec 21 | Dec 26 | Jan 1 | Jan 7 | Jan 18 |
| 28°F58% of yrs | Dec 8 | Dec 15 | Dec 22 | Dec 28 | Jan 1 | Jan 6 | Jan 15 | Jan 22 | Feb 6 |
| 24°F20% of yrs | too rare for a date | ||||||||
| 20°F3% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Pt Comfort, 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 77979 →Compare Port Lavaca with another place →
Weather by month in Port Lavaca
August is the warmest month at Pt Comfort, TX, averaging 92°F by day and 78°F at night; January is the coldest at 64°F and 46°F. From April to October the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 38% of years and March still brings one in 13% of years.
Warmth for growing adds up to 7,902 growing degree days a year (base 50°F), more than at 88% of the 351 Texas stations. 43% of them (3,372) have built up by the end of June, and August adds the most, 1,094. Precipitation totals 41.5 inches a year, most in June (4.9") and least in February (1.8"); May to September bring 50% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 64 | 46 | 3.1 | 63% | 2 | 201 |
| Feb | 68 | 49 | 1.8 | 38% | 1 | 262 |
| Mar | 73 | 57 | 3.2 | 13% | <1 | 456 |
| Apr | 78 | 63 | 2.6 | 0% | 0 | 618 |
| May | 84 | 71 | 4.3 | 0% | 0 | 848 |
| Jun | 89 | 76 | 4.9 | 0% | 0 | 987 |
| Jul | 91 | 78 | 3.2 | 0% | 0 | 1079 |
| Aug | 92 | 78 | 3.4 | 0% | 0 | 1094 |
| Sep | 89 | 73 | 4.8 | 0% | 0 | 927 |
| Oct | 83 | 65 | 3.7 | 0% | 0 | 732 |
| Nov | 74 | 55 | 3.6 | 16% | <1 | 439 |
| Dec | 67 | 48 | 2.9 | 57% | 1 | 260 |
Monthly normals 1991–2020 at Pt Comfort, TX (20 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, Austwell, TX, 20 miles southwest of Port Lavaca, has a last frost 2 days earlier (January 30), a first frost 6 days later (December 27), a season 12 days longer.
When it snows in Port Lavaca, Texas
Measurable snow is rare here: only 0 of 28 winters from 1991 to 2020 recorded 0.1 inch or more at Pt Comfort, TX, 5.8 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 77979
| When | What to do |
|---|---|
| November 23 – December 7 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| December 7 – December 21 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| January 4 – January 18 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| February 1 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by September 28 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by December 7 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| December 21 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 77979 is 6 miles from Pt Comfort, TX, which stands at 20 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 77979 in zone 9b, the band where the coldest night of the year averaged 25 to 30°F (-3.9 to -1.1°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.