Frost Dates for 70817 — Baton Rouge, Louisiana

Half of springs at Lsu Ben-Hur Farm, 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 21. Planting tender crops after March 10 leaves a 30% risk of a frost on them, after March 16 20%, and after March 21 10%. The 21 days between the even-odds date and the one-in-ten date is narrower than at 60% 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 26 in half of years, as early as November 6 one year in ten, and holds off past December 22 one year in ten. A hard freeze of 28°F follows 20 days later, around December 16; in spring the one-in-ten date for 28°F is March 10, 11 days before the 32°F one. The freeze-free season lasts 272 days in a typical year, longer than at 60% of the 88 Louisiana stations; it reaches 309 days one year in ten and falls short of 240 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 16 days longer, to about March 16, and return around November 12. Nights of 24°F, cold enough to damage hardier plants, come in 71% of winters and 16°F in 8%.

July is the warmest month at Lsu Ben-Hur Farm, LA, averaging 91°F by day and 73°F at night; January is the coldest at 61°F and 40°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 79% of years and March still brings one in 45% of years.

Warmth for growing adds up to 6,647 growing degree days a year (base 50°F), more than at 57% of the 88 Louisiana stations. 42% of them (2,813) have built up by the end of June, and July adds the most, 986. Precipitation totals 60.6 inches a year, most in June (6.5") and least in November (4.0"); May to September bring 45% of it.

The nearest other station, Baton Rouge Ryan Airport, LA, 14 miles northwest of Baton Rouge, has a last frost 3 days earlier (February 25), the same first-frost date, a season 4 days longer.

Measurable snow is rare here: only 2 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Baton Rouge Sherwood, LA, 5.2 miles away, so there is no typical first-snow date to plan around.

ZIP 70817 is 10 miles from Lsu Ben-Hur Farm, LA, which stands at 21 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 9 other ZIP codes share the station; its figures are presented in full for 70816 (Baton Rouge). The 2023 USDA Plant Hardiness Zone Map lists ZIP 70817 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.