Frost Dates for 19390 — West Grove, Pennsylvania

Half of springs at Avondale 2 N, PA see their last 32°F night by April 19; only one in ten is past it by April 1, and one in ten still has one after May 3. Planting tender crops after April 24 leaves a 30% risk of a frost on them, after April 28 20%, and after May 3 10%. The 14 days between the even-odds date and the one-in-ten date is narrower than at 86% of the 176 Pennsylvania stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 26 in half of years, as early as October 11 one year in ten, and holds off past November 8 one year in ten. A hard freeze of 28°F follows 9 days later, around November 4; in spring the one-in-ten date for 28°F is April 19, 14 days before the 32°F one. The freeze-free season lasts 189 days in a typical year, longer than at 78% of the 176 Pennsylvania stations; it reaches 209 days one year in ten and falls short of 167 one year in ten. On average 109 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 April 30, and return around October 13. Severe cold of 16°F or below comes every winter, usually between December 17 and March 1.

July is the warmest month at Avondale 2 N, PA, averaging 84°F by day and 64°F at night; January is the coldest at 39°F and 23°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 90% of years and May still brings one in 13% of years.

Warmth for growing adds up to 3,143 growing degree days a year (base 50°F), more than at 64% of the 176 Pennsylvania stations. 34% of them (1,068) have built up by the end of June, and July adds the most, 733. Precipitation totals 47.1 inches a year, most in September (4.5") and least in February (3.1"); May to September bring 45% of it.

The nearest other station, Octoraro Lake, PA, 11 miles west of West Grove, has a last frost 7 days later (April 26), a first frost 4 days earlier (October 22), a season 10 days shorter.

The first measurable snow (0.1 inch or more) in West Grove usually arrives around December 10, and the last of the season around April 5. Those are the middle dates across the winters of 1991–2020 at Coatesville 2 W, PA, 11.4 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 14 days after the last snow.

ZIP 19390 is 4 miles from Avondale 2 N, PA, which stands at 400 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 19348 (Kennett Square). The 2023 USDA Plant Hardiness Zone Map lists ZIP 19390 in zone 7a, the band where the coldest night of the year averaged 0 to 5°F (-17.8 to -15.0°C) over 1991–2020; a zone describes winter lows, not frost dates.