YardThisWeek

Frost dates for ZIP 78578 (Brownsville, TX)

Average last spring and first fall frost dates with 10%, 50% and 90% odds, from NOAA's 1991–2020 climate normals for the nearest weather station, Port Isabel, TX (3 miles away).

Freezes are uncommon here

NOAA's normals for this station show a 32°F night in about 34% of years (about 1 freezing night(s) a year on average). The dates below describe freeze timing for the station's record; in many years there may be no 32°F freeze at all.

JanFebMarAprMayJunJulAugSepOctNovDecLight blue: spring freeze risk (90% to 10%). Tan: fall freeze risk (10% to 90%). Dark lines: 50% dates.

Last spring frost odds

Chance of a 32°F freeze after this dateDate
90% (early: most years still freeze after this)Dec 11 (prior Dec)
50% (the "average" last frost)Jan 3
10% (safe-side: only 1 year in 10 freezes later)Feb 2

Most gardeners plant frost-tender crops (tomatoes, peppers, basil) after the 50% date, and closer to the 10% date for less risk.

First fall frost odds

Chance the first 32°F freeze has happened by this dateDate
10% (early: 1 year in 10 freezes this soon)Dec 7
50% (the "average" first frost)Jan 1 (next year)
90% (late: most years have frozen by now)Feb 1 (next year)

Light frost, freeze and hard freeze

ThresholdLast spring (50%)First fall (50%)
36°F (light frost possible on clear, calm nights)Jan 17Dec 25
32°F (freeze)Jan 3Jan 1 (next year)
28°F (hard freeze)Jan 2Jan 1 (next year)

n/a means NOAA did not publish a date at that threshold for this station (usually because it rarely gets that cold).

This week in Brownsville

Soil temperature now

2-inch depth

70°F 55°F or warmer
24-hour average · latest 73°F, as of Oct 17, 8:00 PM CDT

30°50°55°70°90°

Estimate Not a measurement at this ZIP: distance-weighted average of Russell Farms (17 mi), Weslaco (41 mi), Texas AgriScience (42 mi).

4-inch depth

72°F 55°F or warmer
24-hour average · latest 74°F, as of Oct 17, 8:00 PM CDT

30°50°55°70°90°

Estimate Not a measurement at this ZIP: distance-weighted average of Russell Farms (17 mi), Weslaco (41 mi), Texas AgriScience (42 mi).

Fall: Texas A&M AgriLife times fall pre-emergent (for winter weeds such as annual bluegrass) to soil cooling to about 70°F for several days. The 50–55°F band is the spring trigger. Always read and follow the product label.

7-day forecast and frost risk

No frost in the 7-day forecast.

PeriodHighLowForecast
Tonight59°Partly Cloudy
Sunday77°68°Chance Rain Showers
Monday81°72°Chance Rain Showers
Tuesday84°73°Mostly Sunny then Chance Showers And Thunderstorms
Wednesday84°72°Chance Showers And Thunderstorms
Thursday84°70°Sunny
Friday85°73°Sunny

National Weather Service forecast, issued Oct 17, 8:28 PM CDT. Frost can form above 32°F on clear, calm nights. Full NWS forecast.

Where these numbers come from

Station: Port Isabel, TX (NOAA GHCN-Daily ID USC00417179), elevation 17 ft, 3.5 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).

Nearby stations

StationDistanceLast frost (50%)First frost (50%)
Port Isabel Cameron AP, TX9 miJan 8Jan 4 (next year)
Brownsville, TX11 miJan 6Jan 2 (next year)
WFO Brownsville, TX11 miJan 9Jan 4 (next year)

The average last-frost dates of these stations span 6 days, a rough guide to local variation. See data sources & methods.

Questions

When is the last frost in 78578?

The average (50% chance) last spring freeze of 32°F for ZIP 78578 is January 3. For a safer planting date, use February 2, when only 1 year in 10 still sees a later freeze.

When is the first frost in 78578?

The average first fall freeze is January 1 (next year). In 1 year in 10 it comes by December 7.

What hardiness zone is 78578?

ZIP 78578 is in USDA zone 10a (30 to 35°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.

Other ZIP codes in Cameron County

78520 78521 78526 78535 78550 78552 78559 78566 78567 78575 78583 78586 78592 78593 78597 All Cameron County ZIPs