When is the last frost in Rio Grande City, TX?

For ZIP code 78582, the average last spring frost (32°F) is January 31, based on NOAA 1991-2020 climate normals for the Rio Grande City, TX weather station. There is a 1-in-10 chance of a frost after March 4.

When is the first frost in Rio Grande City, TX?

The average first fall frost (32°F) is December 17. There is a 1-in-10 chance of frost by November 22, so tender plants are at risk from that point on.

How long is the growing season in 78582?

In half of years, the frost-free season (between the last and first 32°F frost) is at least 321 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 78582Rio Grande City, TX

The average last spring frost in Rio Grande City is January 31 and the average first fall frost is December 17, giving a typical growing season of about 321 days. Dates are based on NOAA 1991-2020 climate normals.

Average last spring frost: Jan 31
Average first fall frost: Dec 17
Growing season: 321 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)	Jan 22 · Feb 22 · Mar 14	Nov 11 · Dec 1 · Dec 28	285 days	100%
Frost / freeze (32°F)	Dec 29 · Jan 31 · Mar 4	Nov 22 · Dec 17 · Jan 20	321 days	93%
Hard freeze (28°F)	Dec 13 · Jan 12 · Feb 20	Dec 2 · Dec 29 · Feb 1	357 days	60%

Where these dates come from

ZIP code 78582 is matched to the NOAA station Rio Grande City, TX, 1.9 km away, at 172 ft elevation (11 ft higher than the ZIP code's center). Nearby stations for comparison:

Station	Elevation	Avg last frost	Avg first frost
Rio Grande City, TX (used)	172 ft	Jan 31	Dec 17
Falcon Dam, TX	320 ft	Jan 9	Jan 1
La Joya, TX	213 ft	Jan 23	Dec 28
Mcallen, TX	100 ft	Jan 9	Jan 1

Frost dates near Rio Grande City

Garciasville, TX 78547 · last Jan 31, first Dec 17
Roma, TX 78584 · last Jan 9, first Jan 1
Grulla, TX 78548 · last Jan 31, first Dec 17
Sullivan City, TX 78595 · last Jan 23, first Dec 28
Los Ebanos, TX 78565 · last Jan 23, first Dec 28
Salineno, TX 78585 · last Jan 9, first Jan 1
Santa Elena, TX 78591 · last Jan 23, first Dec 28
Falcon Heights, TX 78545 · last Jan 9, first Jan 1

Frequently asked questions

When is the last frost in Rio Grande City, TX?: For ZIP code 78582, the average last spring frost (32°F) is January 31, based on NOAA 1991-2020 climate normals for the Rio Grande City, TX weather station. There is a 1-in-10 chance of a frost after March 4.
When is the first frost in Rio Grande City, TX?: The average first fall frost (32°F) is December 17. There is a 1-in-10 chance of frost by November 22, so tender plants are at risk from that point on.
How long is the growing season in 78582?: In half of years, the frost-free season (between the last and first 32°F frost) is at least 321 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.