Frost Dates for 01845 — North Andover, Massachusetts

Half of springs at Lawrence Municipal Airport, MA see their last 32°F night by April 21; only one in ten is past it by April 9, and one in ten still has one after May 1. Planting tender crops after April 25 leaves a 30% risk of a frost on them, after April 28 20%, and after May 1 10%. The 10 days between the even-odds date and the one-in-ten date is the narrowest of the 71 Massachusetts stations behind this site's ZIP pages, so the end of frost is fairly predictable.

In fall the first 32°F night comes by October 21 in half of years, as early as October 6 one year in ten, and holds off past November 5 one year in ten. A hard freeze of 28°F follows 11 days later, around November 1; in spring the one-in-ten date for 28°F is April 20, 11 days before the 32°F one. The freeze-free season lasts 182 days in a typical year, longer than at 77% of the 71 Massachusetts stations; it reaches 202 days one year in ten and falls short of 163 one year in ten. On average 123 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 12 days longer, to about May 3, and return around October 9. Severe cold of 16°F or below comes every winter, usually between December 11 and March 11.

July is the warmest month at Lawrence Municipal Airport, MA, averaging 83°F by day and 63°F at night; January is the coldest at 35°F and 19°F. A freezing night is all but certain in every month from November 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 12% of years.

Warmth for growing adds up to 2,840 growing degree days a year (base 50°F), more than at 73% of the 71 Massachusetts stations. 31% of them (867) have built up by the end of June, and July adds the most, 719. Precipitation totals 40.9 inches a year, most in October (4.1") and least in February (2.4"); May to September bring 43% of it.

The nearest other station, Lawrence, MA, 3 miles west of North Andover, has a last frost 8 days earlier (April 13), a first frost 7 days later (October 28), a season 16 days longer.

The first measurable snow (0.1 inch or more) in North Andover usually arrives around December 6, and the last of the season around March 24. Those are the middle dates across the winters of 1991–2020 at Lawrence, MA, 2.9 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 28 days after the last snow.

ZIP 01845 is 2 miles from Lawrence Municipal Airport, MA, which stands at 149 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 01845 in zone 6b, the band where the coldest night of the year averaged -5 to 0°F (-20.6 to -17.8°C) over 1991–2020; a zone describes winter lows, not frost dates.