Frost Dates for 03813 — Center Conway, New Hampshire

Half of springs at N Conway, NH see their last 32°F night by May 7; only one in ten is past it by April 27, and one in ten still has one after May 19. Planting tender crops after May 13 leaves a 30% risk of a frost on them, after May 16 20%, and after May 19 10%. The 12 days between the even-odds date and the one-in-ten date is narrower than at 88% of the 51 New Hampshire stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 5 in half of years, as early as September 23 one year in ten, and holds off past October 20 one year in ten. A hard freeze of 28°F follows 12 days later, around October 17; in spring the one-in-ten date for 28°F is May 9, 10 days before the 32°F one. The freeze-free season lasts 150 days in a typical year, longer than at 55% of the 51 New Hampshire stations; it reaches 168 days one year in ten and falls short of 132 one year in ten. On average 172 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 18, and return around September 26. Severe cold of 16°F or below comes every winter, usually between November 26 and March 25.

July is the warmest month at N Conway, NH, averaging 81°F by day and 58°F at night; January is the coldest at 30°F and 10°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 77% of years.

Warmth for growing adds up to 2,221 growing degree days a year (base 50°F), fewer than at 55% of the 51 New Hampshire stations. 30% of them (677) have built up by the end of June, and July adds the most, 611. Precipitation totals 50.3 inches a year, most in October (5.5") and least in February (3.2"); May to September bring 41% of it.

The nearest other station, Fryeburg E Slopes Airport, ME, 7 miles southeast of Center Conway, has a last frost 10 days later (May 17), a first frost 10 days earlier (September 25), a season 22 days shorter.

The first measurable snow (0.1 inch or more) in Center Conway usually arrives around November 17, and the last of the season around April 9. Those are the middle dates across the winters of 1991–2020 at N Conway, NH, 3.5 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 03813 is 4 miles from N Conway, NH, which stands at 522 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station; its figures are presented in full for 03818 (Conway). The 2023 USDA Plant Hardiness Zone Map lists ZIP 03813 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.