Frost Dates for 78640 — Kyle, Texas

Half of springs at San Marcos, TX see their last 32°F night by February 28; only one in ten is past it by February 1, and one in ten still has one after March 21. Planting tender crops after March 8 leaves a 30% risk of a frost on them, after March 14 20%, and after March 21 10%. The 21 days between the even-odds date and the one-in-ten date is wider than at 50% of the 339 Texas stations behind this site's ZIP pages, so a fixed calendar date is a gamble here.

In fall the first 32°F night comes by November 29 in half of years, as early as November 8 one year in ten, and holds off past December 21 one year in ten. A hard freeze of 28°F follows 16 days later, around December 15; in spring the one-in-ten date for 28°F is March 8, 13 days before the 32°F one. The freeze-free season lasts 273 days in a typical year, longer than at 73% of the 339 Texas stations; it reaches 307 days one year in ten and falls short of 243 one year in ten. On average 20 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 14 days longer, to about March 14, and return around November 16. Nights of 24°F, cold enough to damage hardier plants, come in 75% of winters and 16°F in 9%.

August is the warmest month at San Marcos, TX, averaging 97°F by day and 74°F at night; January is the coldest at 62°F and 39°F. A freezing night is all but certain in every month from December to January (a 90% chance or more). From April to October the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 82% of years and March still brings one in 46% of years.

Warmth for growing adds up to 7,089 growing degree days a year (base 50°F), more than at 70% of the 351 Texas stations. 42% of them (2,951) have built up by the end of June, and August adds the most, 1,093. Precipitation totals 36.5 inches a year, most in May (4.5") and least in February (1.7"); May to September bring 46% of it.

The nearest other station, Austin Bergstrom Airport, TX, 16 miles northeast of Kyle and 185 feet lower, has a last frost 12 days later (March 12), a first frost 13 days earlier (November 16), a season 21 days shorter.

Measurable snow is rare here: only 3 of 25 winters from 1991 to 2020 recorded 0.1 inch or more at San Marcos, TX, 9.9 miles away, so there is no typical first-snow date to plan around.

ZIP 78640 is 10 miles from San Marcos, TX, which stands at 665 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 78666 (San Marcos). The 2023 USDA Plant Hardiness Zone Map lists ZIP 78640 in zone 9a, the band where the coldest night of the year averaged 20 to 25°F (-6.7 to -3.9°C) over 1991–2020; a zone describes winter lows, not frost dates.