Frost Dates for 72390 — West Helena, Arkansas

Half of springs at Helena, AR see their last 32°F night by March 15; only one in ten is past it by February 27, and one in ten still has one after April 1. Planting tender crops after March 23 leaves a 30% risk of a frost on them, after March 28 20%, and after April 1 10%. The 17 days between the even-odds date and the one-in-ten date is narrower than at 41% of the 105 Arkansas stations behind this site's ZIP pages.

In fall the first 32°F night comes by November 16 in half of years, as early as November 2 one year in ten, and holds off past December 4 one year in ten. A hard freeze of 28°F follows 13 days later, around November 29; in spring the one-in-ten date for 28°F is March 21, 11 days before the 32°F one. The freeze-free season lasts 246 days in a typical year, longer than at 94% of the 105 Arkansas stations; it reaches 272 days one year in ten and falls short of 222 one year in ten. On average 53 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 15 days longer, to about March 30, and return around November 5. Nights of 24°F, cold enough to damage hardier plants, come in 99% of winters and 16°F in 62%.

July is the warmest month at Helena, AR, averaging 90°F by day and 73°F at night; January is the coldest at 49°F and 32°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 85% of years and April still brings one in 11% of years.

Warmth for growing adds up to 5,430 growing degree days a year (base 50°F), more than at 75% of the 105 Arkansas stations. 39% of them (2,145) have built up by the end of June, and July adds the most, 978. Precipitation totals 49.7 inches a year, most in April (5.7") and least in September (2.6"); May to September bring 35% of it.

The nearest other station, Marianna 2 S, AR, 15 miles northwest of West Helena, has a last frost 3 days later (March 18), a first frost 5 days earlier (November 11), a season 8 days shorter.

Measurable snow is rare here: only 7 of 25 winters from 1991 to 2020 recorded 0.1 inch or more at Helena, AR, 4.3 miles away, so there is no typical first-snow date to plan around.

ZIP 72390 is 4 miles from Helena, AR, which stands at 195 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 72390 in zone 8a, the band where the coldest night of the year averaged 10 to 15°F (-12.2 to -9.4°C) over 1991–2020; a zone describes winter lows, not frost dates.