Frost Dates for 13603 — Fort Drum, New York

Half of springs at Watertown, NY see their last 32°F night by May 2; only one in ten is past it by April 20, and one in ten still has one after May 17. Planting tender crops after May 8 leaves a 30% risk of a frost on them, after May 12 20%, and after May 17 10%. The 15 days between the even-odds date and the one-in-ten date is narrower than at 29% of the 173 New York stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 13 in half of years, as early as October 1 one year in ten, and holds off past October 28 one year in ten. A hard freeze of 28°F follows 12 days later, around October 25; in spring the one-in-ten date for 28°F is May 6, 11 days before the 32°F one. The freeze-free season lasts 163 days in a typical year, longer than at 50% of the 173 New York stations; it reaches 181 days one year in ten and falls short of 145 one year in ten. On average 144 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 11 days longer, to about May 13, and return around October 2. Severe cold of 16°F or below comes every winter, usually between November 24 and March 27.

July is the warmest month at Watertown, NY, averaging 80°F by day and 62°F at night; January is the coldest at 29°F and 11°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 56% of years.

Warmth for growing adds up to 2,547 growing degree days a year (base 50°F), more than at 53% of the 173 New York stations. 31% of them (795) have built up by the end of June, and July adds the most, 648. Precipitation totals 44.5 inches a year, most in October (5.0") and least in March (2.8"); May to September bring 42% of it.

The nearest other station, Watertown International Airport, NY, 10 miles west of Fort Drum and 179 feet lower, has a last frost 9 days later (May 11), a first frost 12 days earlier (October 1), a season 23 days shorter.

The first measurable snow (0.1 inch or more) in Fort Drum usually arrives around November 19, and the last of the season around April 6. Those are the middle dates across the winters of 1991–2020 at Watertown, NY, 4.7 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 26 days after the last snow.

ZIP 13603 is 5 miles from Watertown, NY, which stands at 497 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 6 other ZIP codes share the station; its figures are presented in full for 13601 (Watertown). The 2023 USDA Plant Hardiness Zone Map lists ZIP 13603 in zone 5a, the band where the coldest night of the year averaged -20 to -15°F (-28.9 to -26.1°C) over 1991–2020; a zone describes winter lows, not frost dates.