Frost Dates for 20705 — Beltsville, Maryland

Half of springs at Beltsville, MD see their last 32°F night by April 10; only one in ten is past it by March 27, and one in ten still has one after May 1. Planting tender crops after April 18 leaves a 30% risk of a frost on them, after April 21 20%, and after May 1 10%. The 21 days between the even-odds date and the one-in-ten date is wider than at 96% of the 50 Maryland 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 1 in half of years, as early as October 16 one year in ten, and holds off past November 14 one year in ten. A hard freeze of 28°F follows 10 days later, around November 11; in spring the one-in-ten date for 28°F is April 10, 21 days before the 32°F one. The freeze-free season lasts 202 days in a typical year, shorter than at 50% of the 50 Maryland stations; it reaches 221 days one year in ten and falls short of 180 one year in ten. On average 95 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 14 days longer, to about April 24, and return around October 21. Severe cold of 16°F or below comes in 99% of winters, usually between December 30 and February 20.

July is the warmest month at Beltsville, MD, averaging 87°F by day and 68°F at night; January is the coldest at 43°F and 25°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 77% of years and May still brings one in 10% of years.

Warmth for growing adds up to 3,927 growing degree days a year (base 50°F), more than at 54% of the 50 Maryland stations. 35% of them (1,374) have built up by the end of June, and July adds the most, 848. Precipitation totals 44.0 inches a year, most in July (4.5") and least in February (2.4"); May to September bring 48% of it.

The nearest other station, Laurel 3 W, MD, 3 miles north of Beltsville and 255 feet higher, has a last frost 5 days earlier (April 5), a first frost 8 days later (November 9), a season 16 days longer.

The first measurable snow (0.1 inch or more) in Beltsville usually arrives around December 14, and the last of the season around March 2. Those are the middle dates across the winters of 1991–2020 at Beltsville, MD, 1.4 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 39 days after the last snow.

ZIP 20705 is 1 mile from Beltsville, MD, which stands at 145 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 9 other ZIP codes share the station; its figures are presented in full for 20904 (Silver Spring). The 2023 USDA Plant Hardiness Zone Map lists ZIP 20705 in zone 7b, the band where the coldest night of the year averaged 5 to 10°F (-15.0 to -12.2°C) over 1991–2020; a zone describes winter lows, not frost dates.