Frost Dates for 70734 — Geismar, Louisiana

Half of springs at Carville 2 SW, LA see their last 32°F night by February 9; only one in ten is past it by January 12, and one in ten still has one after March 10. Planting tender crops after February 23 leaves a 30% risk of a frost on them, after March 1 20%, and after March 10 10%. The 29 days between the even-odds date and the one-in-ten date is wider than at 89% 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 13 in half of years, as early as November 16 one year in ten, and holds off past January 11 one year in ten. A hard freeze of 28°F follows 19 days later, around January 1; in spring the one-in-ten date for 28°F is February 27, 11 days before the 32°F one. The freeze-free season lasts 308 days in a typical year, longer than at 85% of the 88 Louisiana stations; it reaches 343 days one year in ten and falls short of 271 one year in ten. On average 10 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 19 days longer, to about February 28, and return around November 27. A 24°F night is unusual: 36% of winters had one.

July is the warmest month at Carville 2 SW, LA, averaging 90°F by day and 75°F at night; January is the coldest at 62°F and 43°F. From April to October the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 55% of years and March still brings one in 21% of years.

Warmth for growing adds up to 7,025 growing degree days a year (base 50°F), more than at 80% of the 88 Louisiana stations. 43% of them (3,000) have built up by the end of June, and July adds the most, 1,008. Precipitation totals 62.7 inches a year, most in June (7.1") and least in November (4.1"); May to September bring 47% of it.

The nearest other station, Donaldsonville 4 SW, LA, 10 miles south of Geismar, has a last frost 12 days later (February 21), a first frost 8 days earlier (December 5), a season 17 days shorter.

Measurable snow is rare here: only 0 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Carville 2 SW, LA, 7 miles away, so there is no typical first-snow date to plan around.

ZIP 70734 is 7 miles from Carville 2 SW, LA, which stands at 25 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 4 other ZIP codes share the station; its figures are presented in full for 70769 (Prairieville). The 2023 USDA Plant Hardiness Zone Map lists ZIP 70734 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.