When is the last frost in Port Mansfield, TX?

For ZIP code 78598, the average last spring frost (32°F) is January 12, based on NOAA 1991-2020 climate normals for the Port Mansfield, TX weather station. There is a 1-in-10 chance of a frost after February 19.

When is the first frost in Port Mansfield, TX?

The average first fall frost (32°F) is January 1. There is a 1-in-10 chance of frost by December 5, so tender plants are at risk from that point on.

How long is the growing season in 78598?

In half of years, the frost-free season (between the last and first 32°F frost) is at least 362 days long.

Are these frost dates a forecast?

No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.

Frost dates for 78598Port Mansfield, TX

The average last spring frost in Port Mansfield is January 12 and the average first fall frost is January 1, giving a typical growing season of about 362 days. Dates are based on NOAA 1991-2020 climate normals.

Average last spring frost: Jan 12
Average first fall frost: Jan 1
Growing season: 362 days

Frost risk by date

NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.

Spring dates: chance of a frost AFTER the date. Fall dates: chance of a frost BEFORE the date.
Temperature	Last spring: 90% / 50% / 10% chance	First fall: 10% / 50% / 90% chance	Growing season (50%)	Years with at least one
Light frost (36°F)	Dec 24 · Jan 30 · Mar 3	Nov 24 · Dec 19 · Jan 22	327 days	91%
Frost / freeze (32°F)	Dec 15 · Jan 12 · Feb 19	Dec 5 · Jan 1 · Feb 5	362 days	56%
Hard freeze (28°F)	Dec 15 · Jan 7 · Feb 9	Dec 14 · Jan 5 · Feb 3	365 days	17%

Where these dates come from

ZIP code 78598 is matched to the NOAA station Port Mansfield, TX, 0.4 km away, at 9 ft elevation (2 ft higher than the ZIP code's center). Nearby stations for comparison:

Station	Elevation	Avg last frost	Avg first frost
Port Mansfield, TX (used)	9 ft	Jan 12	Jan 1
Raymondville, TX	31 ft	Jan 21	Dec 26
Armstrong 4Se, TX	25 ft	Feb 22	Dec 5
Harlingen Rio Grande Ap, TX	34 ft	Jan 8	Dec 29

Frost dates near Port Mansfield

San Perlita, TX 78590 · last Jan 21, first Dec 26
Rio Hondo, TX 78583 · last Jan 8, first Dec 29
Raymondville, TX 78580 · last Jan 21, first Dec 26
Lyford, TX 78569 · last Jan 21, first Dec 26
South Padre Island, TX 78597 · last Jan 8, first Jan 4
Lozano, TX 78568 · last Jan 8, first Dec 29
Sebastian, TX 78594 · last Jan 10, first Dec 27
Harlingen, TX 78551 · last Jan 9, first Jan 3

Frequently asked questions

When is the last frost in Port Mansfield, TX?: For ZIP code 78598, the average last spring frost (32°F) is January 12, based on NOAA 1991-2020 climate normals for the Port Mansfield, TX weather station. There is a 1-in-10 chance of a frost after February 19.
When is the first frost in Port Mansfield, TX?: The average first fall frost (32°F) is January 1. There is a 1-in-10 chance of frost by December 5, so tender plants are at risk from that point on.
How long is the growing season in 78598?: In half of years, the frost-free season (between the last and first 32°F frost) is at least 362 days long.
Are these frost dates a forecast?: No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.