Frost Dates for 55072 — Sandstone, Minnesota

Half of springs at Sandstone 6 W, MN see their last 32°F night by May 13; only one in ten is past it by April 29, and one in ten still has one after May 28. Planting tender crops after May 19 leaves a 30% risk of a frost on them, after May 22 20%, and after May 28 10%. The 15 days between the even-odds date and the one-in-ten date is wider than at 64% of the 142 Minnesota stations behind this site's ZIP pages.

In fall the first 32°F night comes by September 29 in half of years, as early as September 15 one year in ten, and holds off past October 13 one year in ten. A hard freeze of 28°F follows 11 days later, around October 10; in spring the one-in-ten date for 28°F is May 15, 13 days before the 32°F one. The freeze-free season lasts 137 days in a typical year, shorter than at 83% of the 142 Minnesota stations; it reaches 159 days one year in ten and falls short of 116 one year in ten. On average 177 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 24, and return around September 19. Severe cold of 16°F or below comes every winter, usually between November 12 and April 2.

July is the warmest month at Sandstone 6 W, MN, averaging 79°F by day and 56°F at night; January is the coldest at 20°F and 2°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 83% of years.

Warmth for growing adds up to 1,916 growing degree days a year (base 50°F), fewer than at 85% of the 142 Minnesota stations. 31% of them (588) have built up by the end of June, and July adds the most, 541. Precipitation totals 33.5 inches a year, most in July (5.6") and least in January (0.8"); May to September bring 61% of it.

The nearest other station, Hinckley, MN, 17 miles southwest of Sandstone, has a last frost 3 days later (May 16), a first frost 5 days earlier (September 24), a season 7 days shorter.

The first measurable snow (0.1 inch or more) in Sandstone usually arrives around November 6, and the last of the season around April 19. Those are the middle dates across the winters of 1991–2020 at Bruno 7ENE, MN, 14.5 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 24 days after the last snow.

ZIP 55072 is 14 miles from Sandstone 6 W, MN, which stands at 1,130 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 55072 in zone 4a, the band where the coldest night of the year averaged -30 to -25°F (-34.4 to -31.7°C) over 1991–2020; a zone describes winter lows, not frost dates.