USDA Hardiness Zone 10a
Frost Dates for 78520 — Brownsville, Texas
NOAA 1991–2020 normals from WFO Brownsville, TX (15 ft), 6 miles east.
Updated
Frost is not a yearly event in Brownsville: a night at or below 32°F came in 31% of the winters of 1991–2020 at WFO Brownsville, TX, and a 36°F night, cold enough for frost on exposed leaves, in 75%. There is no reliable "last frost date" here; most years have none.
- Winters with a freeze
- 31%
- Winters with 36°F
- 75%
- Coldest month low
- —
- Hardiness zone
- 10a
32°F or below, 1991–2020
frost possible on leaves
30 to 35°F (-1.1 to 1.7°C) coldest night
- First snow
- Rare
- Last snow
- Rare
- Winters with snow
- 5%
- Snow per year
- 0.2"
median, 1991–2020
median, 1991–2020
1 of 20 observed
NOAA normal
Frost risk by date in Brownsville
At WFO Brownsville, TX, 6 miles east of Brownsville, 31% of the winters of 1991–2020 had at least one night at or below 32°F, 9% reached 28°F. Nights of 36°F, enough for frost on exposed leaves, are more common (75% of winters) and, when they come, fall between about December 30 and January 25. 11 of the 351 other Texas stations behind this site's ZIP pages freeze in fewer than half of winters too.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F75% of yrs | Dec 16 | Dec 30 | Jan 7 | Jan 17 | Jan 25 | Feb 1 | Feb 11 | Feb 26 | Mar 7 |
| 32°F31% of yrs | too rare for a date | ||||||||
| 28°F9% of yrs | too rare for a date | ||||||||
| 24°F1% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F75% of yrs | Nov 30 | Dec 7 | Dec 14 | Dec 23 | Dec 30 | Jan 3 | Jan 9 | Jan 21 | Feb 7 |
| 32°F31% of yrs | too rare for a date | ||||||||
| 28°F9% of yrs | too rare for a date | ||||||||
| 24°F1% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at WFO Brownsville, 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 78520 →Compare Brownsville with another place →
Compared with the next station
The nearest other station, Port Isabel, TX, 17 miles northeast of Brownsville, has a 32°F night in 34% of winters against 31% here.
When it snows in Brownsville, Texas
Measurable snow is rare here: only 1 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Port Isabel, TX, 17.2 miles away, so there is no typical first-snow date to plan around.
Where these figures come from
ZIP 78520 is 6 miles from WFO Brownsville, TX, which stands at 15 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station; its figures are presented in full for 78521 (Brownsville). The 2023 USDA Plant Hardiness Zone Map lists ZIP 78520 in zone 10a, the band where the coldest night of the year averaged 30 to 35°F (-1.1 to 1.7°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.