Frost Dates for 30450 — Portal, Georgia

Half of springs at Rocky Ford 4SE, GA see their last 32°F night by March 14; only one in ten is past it by February 19, and one in ten still has one after April 5. Planting tender crops after March 22 leaves a 30% risk of a frost on them, after March 28 20%, and after April 5 10%. The 22 days between the even-odds date and the one-in-ten date is wider than at 90% of the 127 Georgia 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 15 in half of years, as early as November 1 one year in ten, and holds off past December 5 one year in ten. A hard freeze of 28°F follows 14 days later, around November 29; in spring the one-in-ten date for 28°F is March 20, 16 days before the 32°F one. The freeze-free season lasts 248 days in a typical year, longer than at 65% of the 127 Georgia stations; it reaches 278 days one year in ten and falls short of 222 one year in ten. On average 44 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 30, and return around November 5. Nights of 24°F, cold enough to damage hardier plants, come in 94% of winters and 16°F in 25%.

July is the warmest month at Rocky Ford 4SE, GA, averaging 92°F by day and 71°F at night; January is the coldest at 58°F and 36°F. A freezing night is all but certain in every month from December to February (a 90% chance or more). From May to October the chance of a 32°F night stays under 10% each month. In spring, March still brings one in 72% of years and April still brings one in 15% of years.

Warmth for growing adds up to 5,789 growing degree days a year (base 50°F), more than at 61% of the 127 Georgia stations. 41% of them (2,352) have built up by the end of June, and July adds the most, 970. Precipitation totals 48.4 inches a year, most in July (5.9") and least in November (2.9"); May to September bring 48% of it.

The nearest other station, Metter, GA, 14 miles southwest of Portal, has a last frost 12 days earlier (March 2), a first frost 12 days later (November 27), a season 21 days longer.

Measurable snow is rare here: only 0 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Brooklet 1 W, GA, 19.1 miles away, so there is no typical first-snow date to plan around.

ZIP 30450 is 10 miles from Rocky Ford 4SE, GA, which stands at 160 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station; its figures are presented in full for 30467 (Sylvania). The 2023 USDA Plant Hardiness Zone Map lists ZIP 30450 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.