Frost Dates for 79079 — Shamrock, Texas

Half of springs at Shamrock #2, TX see their last 32°F night by April 9; only one in ten is past it by March 26, and one in ten still has one after April 26. Planting tender crops after April 16 leaves a 30% risk of a frost on them, after April 20 20%, and after April 26 10%. The 17 days between the even-odds date and the one-in-ten date is narrower than at 86% of the 339 Texas stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 30 in half of years, as early as October 17 one year in ten, and holds off past November 11 one year in ten. A hard freeze of 28°F follows 7 days later, around November 6; in spring the one-in-ten date for 28°F is April 17, 9 days before the 32°F one. The freeze-free season lasts 202 days in a typical year, shorter than at 94% of the 339 Texas stations; it reaches 224 days one year in ten and falls short of 181 one year in ten. On average 97 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 11 days longer, to about April 20, and return around October 22. Severe cold of 16°F or below comes every winter, usually between December 10 and February 21.

July is the warmest month at Shamrock #2, TX, averaging 94°F by day and 68°F at night; January is the coldest at 50°F and 24°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 80% of years.

Warmth for growing adds up to 4,634 growing degree days a year (base 50°F), fewer than at 94% of the 351 Texas stations. 37% of them (1,715) have built up by the end of June, and July adds the most, 953. Precipitation totals 25.2 inches a year, most in June (3.7") and least in January (0.8"); May to September bring 58% of it.

The nearest other station, Wellington, TX, 27 miles south of Shamrock and 320 feet lower, has a last frost 8 days earlier (April 1), a first frost 5 days later (November 4), a season 13 days longer.

The first measurable snow (0.1 inch or more) in Shamrock usually arrives around December 11, and the last of the season around February 15. Those are the middle dates across the winters of 1991–2020 at Shamrock #2, TX, 1.6 miles away: half of years saw snow earlier, half later. Snow fell in 73% of those winters. The last 32°F night of spring typically comes 53 days after the last snow.

ZIP 79079 is 2 miles from Shamrock #2, TX, which stands at 2,360 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 79079 in zone 7b, the band where the coldest night of the year averaged 5 to 10°F (-15.0 to -12.2°C) over 1991–2020; a zone describes winter lows, not frost dates.