Frost Dates for 75089 — Rowlett, Texas

Half of springs at Lavon Dam, TX see their last 32°F night by March 10; only one in ten is past it by February 20, and one in ten still has one after March 31. Planting tender crops after March 18 leaves a 30% risk of a frost on them, after March 23 20%, and after March 31 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 19 in half of years, as early as November 1 one year in ten, and holds off past December 5 one year in ten. A hard freeze of 28°F follows 12 days later, around December 1; in spring the one-in-ten date for 28°F is March 17, 14 days before the 32°F one. The freeze-free season lasts 254 days in a typical year, longer than at 58% of the 339 Texas stations; it reaches 278 days one year in ten and falls short of 227 one year in ten. On average 44 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 16 days longer, to about March 26, and return around November 8. Nights of 24°F, cold enough to damage hardier plants, come in 99% of winters and 16°F in 34%.

August is the warmest month at Lavon Dam, TX, averaging 93°F by day and 73°F at night; January is the coldest at 54°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 October the chance of a 32°F night stays under 10% each month. In spring, March still brings one in 73% of years and April still brings one in 10% of years.

Warmth for growing adds up to 5,884 growing degree days a year (base 50°F), fewer than at 78% of the 351 Texas stations. 39% of them (2,298) have built up by the end of June, and August adds the most, 1,027. Precipitation totals 39.8 inches a year, most in May (4.7") and least in July (1.9"); May to September bring 40% of it.

The nearest other station, Richardson, TX, 12 miles northwest of Rowlett and 168 feet higher, has a last frost 3 days earlier (March 7), a first frost 2 days later (November 21), a season 5 days longer.

Measurable snow is rare here: only 2 of 19 winters from 1991 to 2020 recorded 0.1 inch or more at Rockwall, TX, 4.8 miles away, so there is no typical first-snow date to plan around.

ZIP 75089 is 9 miles from Lavon Dam, TX, which stands at 510 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 10 other ZIP codes share the station; its figures are presented in full for 75098 (Wylie). The 2023 USDA Plant Hardiness Zone Map lists ZIP 75089 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.