Frost Dates for 21113 — Odenton, Maryland

Half of springs at Baltimore Wash International Airport, 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 April 25. Planting tender crops after April 16 leaves a 30% risk of a frost on them, after April 19 20%, and after April 25 10%. The 15 days between the even-odds date and the one-in-ten date is narrower than at 52% of the 50 Maryland stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 31 in half of years, as early as October 17 one year in ten, and holds off past November 12 one year in ten. A hard freeze of 28°F follows 10 days later, around November 10; in spring the one-in-ten date for 28°F is April 10, 15 days before the 32°F one. The freeze-free season lasts 204 days in a typical year, longer than at 54% of the 50 Maryland stations; it reaches 223 days one year in ten and falls short of 183 one year in ten. On average 93 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 27 and February 20.

July is the warmest month at Baltimore Wash International Airport, MD, averaging 89°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 May to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 78% of years.

Warmth for growing adds up to 4,007 growing degree days a year (base 50°F), more than at 62% of the 50 Maryland stations. 35% of them (1,415) have built up by the end of June, and July adds the most, 876. Precipitation totals 45.0 inches a year, most in July (4.5") and least in February (2.9"); May to September bring 46% of it.

The nearest other station, Glenn Dale Bell Stn, MD, 9 miles southwest of Odenton, has a last frost 12 days later (April 22), a first frost 9 days earlier (October 22), a season 21 days shorter.

The first measurable snow (0.1 inch or more) in Odenton usually arrives around December 11, and the last of the season around March 11. Those are the middle dates across the winters of 1991–2020 at Baltimore Wash International Airport, MD, 6.1 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 30 days after the last snow.

ZIP 21113 is 6 miles from Baltimore Wash International Airport, MD, which stands at 156 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 12 other ZIP codes share the station; its figures are presented in full for 21061 (Glen Burnie). The 2023 USDA Plant Hardiness Zone Map lists ZIP 21113 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.