Frost Dates for 78605 — Bertram, Texas

Half of springs at Austin 33 NW, TX see their last 32°F night by March 2; only one in ten is past it by February 6, and one in ten still has one after March 20. Planting tender crops after March 9 leaves a 30% risk of a frost on them, after March 14 20%, and after March 20 10%. The 18 days between the even-odds date and the one-in-ten date is narrower than at 75% of the 339 Texas stations behind this site's ZIP pages.

In fall the first 32°F night comes by November 29 in half of years, as early as November 10 one year in ten, and holds off past December 19 one year in ten. A hard freeze of 28°F follows 14 days later, around December 13; in spring the one-in-ten date for 28°F is March 11, 9 days before the 32°F one. The freeze-free season lasts 274 days in a typical year, longer than at 74% of the 339 Texas stations; it reaches 304 days one year in ten and falls short of 245 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 12 days longer, to about March 14, and return around November 18. Nights of 24°F, cold enough to damage hardier plants, come in 77% of winters and 16°F in 10%.

August is the warmest month at Austin 33 NW, TX, averaging 95°F by day and 73°F at night; January is the coldest at 60°F and 40°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 85% of years and March still brings one in 55% of years.

Warmth for growing adds up to 6,738 growing degree days a year (base 50°F), more than at 63% of the 351 Texas stations. 42% of them (2,800) have built up by the end of June, and August adds the most, 1,050. Precipitation totals 33.2 inches a year, most in May (4.0") and least in January (1.9"); May to September bring 45% of it.

The nearest other station, Burnet, TX, 12 miles west of Bertram, has a last frost 13 days later (March 15), a first frost 18 days earlier (November 11), a season 31 days shorter.

Measurable snow is rare here: only 1 of 25 winters from 1991 to 2020 recorded 0.1 inch or more at Bertram 3 ENE, TX, 0.9 miles away, so there is no typical first-snow date to plan around.

ZIP 78605 is 10 miles from Austin 33 NW, TX, which stands at 1,361 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station; its figures are presented in full for 78642 (Liberty Hill). The 2023 USDA Plant Hardiness Zone Map lists ZIP 78605 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.