Frost Dates for 78643 — Llano, Texas

Half of springs at Llano, TX see their last 32°F night by March 20; only one in ten is past it by February 28, and one in ten still has one after April 11. Planting tender crops after March 31 leaves a 30% risk of a frost on them, after April 4 20%, and after April 11 10%. The 22 days between the even-odds date and the one-in-ten date is wider than at 63% 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 10 in half of years, as early as October 28 one year in ten, and holds off past November 30 one year in ten. A hard freeze of 28°F follows 11 days later, around November 21; in spring the one-in-ten date for 28°F is March 26, 16 days before the 32°F one. The freeze-free season lasts 235 days in a typical year, shorter than at 69% of the 339 Texas stations; it reaches 264 days one year in ten and falls short of 207 one year in ten. On average 50 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 15 days longer, to about April 4, and return around November 3. Nights of 24°F, cold enough to damage hardier plants, come in 99% of winters and 16°F in 50%.

August is the warmest month at Llano, TX, averaging 97°F by day and 72°F at night; January is the coldest at 62°F and 34°F. A freezing night is all but certain in every month from December to February (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, March still brings one in 84% of years and April still brings one in 29% of years.

Warmth for growing adds up to 6,680 growing degree days a year (base 50°F), more than at 61% of the 351 Texas stations. 41% of them (2,758) have built up by the end of June, and August adds the most, 1,072. Precipitation totals 27.6 inches a year, most in May (3.9") and least in January (1.5"); May to September bring 47% of it.

The nearest other station, Burnet Municipal Airport, TX, 26 miles east of Llano and 268 feet higher, has a last frost 14 days earlier (March 6), a first frost 13 days later (November 23), a season 27 days longer.

Measurable snow is rare here: only 1 of 25 winters from 1991 to 2020 recorded 0.1 inch or more at Llano, TX, 1.6 miles away, so there is no typical first-snow date to plan around.

ZIP 78643 is 2 miles from Llano, TX, which stands at 1,020 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station; its figures are presented in full for 78639 (Kingsland). The 2023 USDA Plant Hardiness Zone Map lists ZIP 78643 in zone 8b, the band where the coldest night of the year averaged 15 to 20°F (-9.4 to -6.7°C) over 1991–2020; a zone describes winter lows, not frost dates.