Frost Dates for 70403 — Hammond, Louisiana

Half of springs at Hammond 5 E, LA see their last 32°F night by March 8; only one in ten is past it by February 12, 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 23 days between the even-odds date and the one-in-ten date is wider than at 52% 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 19 in half of years, as early as November 3 one year in ten, and holds off past December 8 one year in ten. A hard freeze of 28°F follows 13 days later, around December 2; 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 257 days in a typical year, shorter than at 64% of the 88 Louisiana stations; it reaches 289 days one year in ten and falls short of 227 one year in ten. On average 31 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 17 days longer, to about March 25, and return around November 6. Nights of 24°F, cold enough to damage hardier plants, come in 88% of winters and 16°F in 18%.

July is the warmest month at Hammond 5 E, LA, averaging 92°F by day and 72°F at night; January is the coldest at 62°F and 38°F. A freezing night is all but certain in every month from December to 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 89% of years and March still brings one in 62% of years.

Warmth for growing adds up to 6,460 growing degree days a year (base 50°F), fewer than at 58% of the 88 Louisiana stations. 42% of them (2,701) have built up by the end of June, and July adds the most, 976. Precipitation totals 64.4 inches a year, most in July (6.8") and least in October (4.1"); May to September bring 45% of it.

The nearest other station, Amite, LA, 16 miles north of Hammond, has a last frost 1 day earlier (March 7), a first frost 1 day earlier (November 18).

Measurable snow is rare here: only 1 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Ponchatoula, LA, 2.3 miles away, so there is no typical first-snow date to plan around.

ZIP 70403 is 6 miles from Hammond 5 E, LA, which stands at 35 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 7 other ZIP codes share the station; its figures are presented in full for 70454 (Ponchatoula). The 2023 USDA Plant Hardiness Zone Map lists ZIP 70403 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.