Frost Dates for 68138 — Omaha, Nebraska

Half of springs at Gretna 4NE, NE see their last 32°F night by April 21; only one in ten is past it by April 5, and one in ten still has one after May 4. Planting tender crops after April 27 leaves a 30% risk of a frost on them, after April 30 20%, and after May 4 10%. The 13 days between the even-odds date and the one-in-ten date is narrower than at 29% of the 68 Nebraska stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 18 in half of years, as early as October 4 one year in ten, and holds off past October 31 one year in ten. A hard freeze of 28°F follows 9 days later, around October 27; in spring the one-in-ten date for 28°F is April 25, 9 days before the 32°F one. The freeze-free season lasts 179 days in a typical year, longer than at 90% of the 68 Nebraska stations; it reaches 197 days one year in ten and falls short of 159 one year in ten. On average 136 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 10 days longer, to about May 1, and return around October 8. Severe cold of 16°F or below comes every winter, usually between November 23 and March 12.

July is the warmest month at Gretna 4NE, NE, averaging 86°F by day and 66°F at night; January is the coldest at 32°F and 14°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 18% of years.

Warmth for growing adds up to 3,408 growing degree days a year (base 50°F), more than at 68% of the 68 Nebraska stations. 35% of them (1,206) have built up by the end of June, and July adds the most, 801. Precipitation totals 33.3 inches a year, most in June (5.4") and least in January (0.9"); May to September bring 62% of it.

The nearest other station, Springfield 7E, NE, 10 miles southeast of Omaha and 175 feet lower, has a last frost 4 days earlier (April 17), a first frost 1 day later (October 19), a season 4 days longer.

The first measurable snow (0.1 inch or more) in Omaha usually arrives around November 22, and the last of the season around March 29. Those are the middle dates across the winters of 1991–2020 at Gretna 4NE, NE, 3.3 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 23 days after the last snow.

ZIP 68138 is 3 miles from Gretna 4NE, NE, which stands at 1,240 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 10 other ZIP codes share the station; its figures are presented in full for 68135 (Omaha). The 2023 USDA Plant Hardiness Zone Map lists ZIP 68138 in zone 6a, the band where the coldest night of the year averaged -10 to -5°F (-23.3 to -20.6°C) over 1991–2020; a zone describes winter lows, not frost dates.