Rio Grande City, TX 78536 Frost Dates
Rio Grande City, TX: when does the frost end?
Typically, the last spring freeze lands around 01/31, roughly 156 days out. Fall's first freeze usually shows up around 12/17, roughly 321 days after the last spring frost.
Rio Grande City sits in USDA Zone 9b (25 to 30°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
With roughly 16 weeks until Rio Grande City's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
01/31 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/04 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 12/29 and only about 1 year in 10 sees frost after that.
Rio Grande City against the rest of the dataset
At roughly 321 frost-free days, Rio Grande City places 3,292 of 40,283 ZIP codes in this dataset. Within TX, it ranks 207 of 2,558.
Learn more
Before leaning on 78536's figures: local microclimates explains what one yard in Rio Grande City can differ from the 78536 normal, while zone vs. frost date explains why Zone 9b and Rio Grande City's frost date answer different questions.