Frost Dates for 70346 — Donaldsonville, Louisiana

Half of springs at Donaldsonville 4 SW, LA see their last 32°F night by February 21; only one in ten is past it by January 23, and one in ten still has one after March 15. Planting tender crops after March 3 leaves a 30% risk of a frost on them, after March 8 20%, and after March 15 10%. The 22 days between the even-odds date and the one-in-ten date is narrower than at 49% of the 88 Louisiana 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 December 5 in half of years, as early as November 14 one year in ten, and holds off past January 6 one year in ten. A hard freeze of 28°F follows 23 days later, around December 28; in spring the one-in-ten date for 28°F is March 5, 10 days before the 32°F one. The freeze-free season lasts 291 days in a typical year, longer than at 70% of the 88 Louisiana stations; it reaches 330 days one year in ten and falls short of 257 one year in ten. On average 16 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 13 days longer, to about March 6, and return around November 20. Nights of 24°F, cold enough to damage hardier plants, come in 55% of winters and 16°F in 5%.

July is the warmest month at Donaldsonville 4 SW, LA, averaging 91°F by day and 74°F at night; January is the coldest at 62°F and 42°F. From April to October the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 69% of years and March still brings one in 34% of years.

Warmth for growing adds up to 6,896 growing degree days a year (base 50°F), more than at 72% of the 88 Louisiana stations. 43% of them (2,953) have built up by the end of June, and July adds the most, 994. Precipitation totals 63.5 inches a year, most in June (7.0") and least in March (4.0"); May to September bring 49% of it.

The nearest other station, Carville 2 SW, LA, 10 miles northwest of Donaldsonville, has a last frost 12 days earlier (February 9), a first frost 8 days later (December 13), a season 17 days longer.

Measurable snow is rare here: only 2 of 23 winters from 1991 to 2020 recorded 0.1 inch or more at Donaldsonville 4 SW, LA, 2.7 miles away, so there is no typical first-snow date to plan around.

ZIP 70346 is 3 miles from Donaldsonville 4 SW, LA, which stands at 30 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 5 other ZIP codes share the station; its figures are presented in full for 70774 (Saint Amant). The 2023 USDA Plant Hardiness Zone Map lists ZIP 70346 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.