USDA Hardiness Zone 9b
Frost Dates for 78380 — Robstown, Texas
NOAA 1991–2020 normals from Robstown, TX (85 ft), 2 miles east.
Updated
A freeze (32°F) reaches Robstown in 82% of winters. When it does, the first fall frost comes around December 24 and the last spring frost around January 26; after March 3 the chance of another is under 8%.
- Last spring frost
- January 26
- First fall frost
- December 24
- Winters with a freeze
- 82%
- Hardiness zone
- 9b
50%, in freezing years
50%, in freezing years
32°F or below, 1991–2020
25 to 30°F (-3.9 to -1.1°C) coldest night
- First snow
- Rare
- Last snow
- Rare
- Winters with snow
- 9%
- Snow per year
- 0.2"
median, 1991–2020
median, 1991–2020
2 of 23 observed
NOAA normal
Frost risk by date in Robstown
In the 82% of winters that bring a 32°F night, half of springs at Robstown, TX see their last 32°F night by January 26; only one in ten is past it by December 18, and one in ten still has one after March 3. Counting the winters with no freeze at all, the risk of a 32°F night after March 3 is under 8% and after January 26 41%. The 36 days between the even-odds date and the one-in-ten date is wider than at 97% 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 24 in half of years, as early as November 28 one year in ten, and holds off past February 2 one year in ten. A hard freeze of 28°F is less common: it came in 36% of winters. The freeze-free season lasts 336 days in a typical year, longer than at 96% of the 339 Texas stations; it reaches 365 days one year in ten and falls short of 290 one year in ten. On average 4 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 20 days longer, to about February 15, and return around December 8. A 24°F night is unusual: 6% of winters had one.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F99% of yrs | Jan 13 | Jan 26 | Feb 3 | Feb 9 | Feb 15 | Feb 21 | Feb 28 | Mar 4 | Mar 12 |
| 32°F82% of yrs | Dec 18 | Dec 29 | Jan 7 | Jan 16 | Jan 26 | Feb 2 | Feb 9 | Feb 20 | Mar 3 |
| 28°F36% of yrs | too rare for a date | ||||||||
| 24°F6% of yrs | too rare for a date | ||||||||
| 20°F0% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F99% of yrs | Nov 16 | Nov 24 | Nov 29 | Dec 3 | Dec 8 | Dec 13 | Dec 20 | Dec 29 | Jan 7 |
| 32°F82% of yrs | Nov 28 | Dec 5 | Dec 11 | Dec 18 | Dec 24 | Jan 1 | Jan 6 | Jan 15 | Feb 2 |
| 28°F36% of yrs | too rare for a date | ||||||||
| 24°F6% of yrs | too rare for a date | ||||||||
| 20°F0% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Robstown, 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 78380 →Compare Robstown with another place →
Weather by month in Robstown
August is the warmest month at Robstown, TX, averaging 96°F by day and 76°F at night; January is the coldest at 68°F and 47°F. From April to October the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 28% of years and March still brings one in 11% of years.
Warmth for growing adds up to 8,522 growing degree days a year (base 50°F), more than at 93% of the 351 Texas stations. 44% of them (3,754) have built up by the end of June, and August adds the most, 1,121. Precipitation totals 31.1 inches a year, most in September (5.0") and least in January (1.5"); May to September bring 55% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 68 | 47 | 1.5 | 44% | 2 | 259 |
| Feb | 72 | 51 | 1.5 | 28% | 1 | 332 |
| Mar | 77 | 57 | 2.2 | 11% | <1 | 538 |
| Apr | 83 | 64 | 1.7 | 0% | 0 | 701 |
| May | 88 | 70 | 3.3 | 0% | 0 | 905 |
| Jun | 93 | 75 | 3.0 | 0% | 0 | 1018 |
| Jul | 95 | 76 | 2.8 | 0% | 0 | 1093 |
| Aug | 96 | 76 | 3.0 | 0% | 0 | 1121 |
| Sep | 92 | 72 | 5.0 | 0% | 0 | 965 |
| Oct | 86 | 65 | 3.3 | 0% | 0 | 782 |
| Nov | 77 | 56 | 2.1 | 10% | <1 | 495 |
| Dec | 70 | 49 | 1.7 | 42% | 1 | 314 |
Monthly normals 1991–2020 at Robstown, TX (85 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, Corpus Christi, TX, 11 miles east of Robstown, has a last frost 2 days later (January 28), a first frost 3 days earlier (December 21), a season 5 days shorter.
When it snows in Robstown, Texas
Measurable snow is rare here: only 2 of 23 winters from 1991 to 2020 recorded 0.1 inch or more at Robstown, TX, 1.6 miles away, so there is no typical first-snow date to plan around.
Where these figures come from
ZIP 78380 is 2 miles from Robstown, TX, which stands at 85 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station; its figures are presented in full for 78410 (Corpus Christi). The 2023 USDA Plant Hardiness Zone Map lists ZIP 78380 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.