Frost Dates for 70577 — Port Barre, Louisiana

Half of springs at Grand Coteau, LA see their last 32°F night by February 28; only one in ten is past it by January 31, and one in ten still has one after March 25. Planting tender crops after March 10 leaves a 30% risk of a frost on them, after March 16 20%, and after March 25 10%. The 25 days between the even-odds date and the one-in-ten date is wider than at 69% 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 November 23 in half of years, as early as November 5 one year in ten, and holds off past December 16 one year in ten. A hard freeze of 28°F follows 15 days later, around December 8; in spring the one-in-ten date for 28°F is March 8, 17 days before the 32°F one. The freeze-free season lasts 267 days in a typical year, shorter than at 51% of the 88 Louisiana stations; it reaches 301 days one year in ten and falls short of 237 one year in ten. On average 18 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 18 days longer, to about March 18, and return around November 13. Nights of 24°F, cold enough to damage hardier plants, come in 75% of winters and 16°F in 10%.

August is the warmest month at Grand Coteau, LA, averaging 92°F by day and 72°F at night; January is the coldest at 64°F and 41°F. A freezing night is all but certain in 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 77% of years and March still brings one in 45% of years.

Warmth for growing adds up to 6,929 growing degree days a year (base 50°F), more than at 73% of the 88 Louisiana stations. 43% of them (2,978) have built up by the end of June, and August adds the most, 997. Precipitation totals 61.6 inches a year, most in June (7.0") and least in March (3.8"); May to September bring 43% of it.

The nearest other station, Lafayette Regional Airport, LA, 24 miles south of Port Barre, has a last frost 15 days earlier (February 13), a first frost 11 days later (December 4), a season 32 days longer.

Measurable snow is rare here: only 0 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Grand Coteau, LA, 11.3 miles away, so there is no typical first-snow date to plan around.

ZIP 70577 is 11 miles from Grand Coteau, LA, which stands at 55 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 6 other ZIP codes share the station; its figures are presented in full for 70570 (Opelousas). The 2023 USDA Plant Hardiness Zone Map lists ZIP 70577 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.