Frost Dates for 39272 — Byram, Mississippi

Half of springs at Oakley Exp Stn, MS see their last 32°F night by March 16; only one in ten is past it by February 25, and one in ten still has one after April 6. Planting tender crops after March 26 leaves a 30% risk of a frost on them, after March 31 20%, and after April 6 10%. The 21 days between the even-odds date and the one-in-ten date is wider than at 73% of the 96 Mississippi 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 6 in half of years, as early as October 24 one year in ten, and holds off past November 26 one year in ten. A hard freeze of 28°F follows 12 days later, around November 18; in spring the one-in-ten date for 28°F is March 21, 16 days before the 32°F one. The freeze-free season lasts 236 days in a typical year, shorter than at 57% of the 96 Mississippi stations; it reaches 261 days one year in ten and falls short of 210 one year in ten. On average 54 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 April 2, and return around October 30. Nights of 24°F, cold enough to damage hardier plants, come in 99% of winters and 16°F in 50%.

July is the warmest month at Oakley Exp Stn, MS, averaging 93°F by day and 71°F at night; January is the coldest at 59°F and 35°F. A freezing night is all but certain in every month from November to February (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, March still brings one in 79% of years and April still brings one in 20% of years.

Warmth for growing adds up to 6,186 growing degree days a year (base 50°F), more than at 70% of the 96 Mississippi stations. 41% of them (2,550) have built up by the end of June, and July adds the most, 1,001. Precipitation totals 60.3 inches a year, most in January (5.9") and least in October (4.0"); May to September bring 39% of it.

The nearest other station, Jackson Hawkins Field, MS, 10 miles east of Byram, has a last frost 10 days earlier (March 6), a first frost 13 days later (November 19), a season 22 days longer.

Measurable snow is rare here: only 4 of 30 winters from 1991 to 2020 recorded 0.1 inch or more at Oakley Exp Stn, MS, 9.9 miles away, so there is no typical first-snow date to plan around.

ZIP 39272 is 10 miles from Oakley Exp Stn, MS, which stands at 205 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 5 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 39272 in zone 8b, the band where the coldest night of the year averaged 15 to 20°F (-9.4 to -6.7°C) over 1991–2020; a zone describes winter lows, not frost dates.