Frost Dates for 58545 — Hazen, North Dakota

Half of springs at Beulah 1 W, ND see their last 32°F night by May 21; only one in ten is past it by May 7, and one in ten still has one after June 3. Planting tender crops after May 26 leaves a 30% risk of a frost on them, after May 30 20%, and after June 3 10%. The 13 days between the even-odds date and the one-in-ten date is narrower than at 21% of the 33 North Dakota stations behind this site's ZIP pages.

In fall the first 32°F night comes by September 20 in half of years, as early as September 5 one year in ten, and holds off past October 4 one year in ten. A hard freeze of 28°F follows 8 days later, around September 28; in spring the one-in-ten date for 28°F is May 25, 9 days before the 32°F one. The freeze-free season lasts 121 days in a typical year, the shortest of the 33 North Dakota stations; it reaches 141 days one year in ten and falls short of 99 one year in ten. On average 191 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 10 days longer, to about May 31, and return around September 10. Severe cold of 16°F or below comes every winter, usually between October 29 and April 11.

July is the warmest month at Beulah 1 W, ND, averaging 86°F by day and 56°F at night; January is the coldest at 23°F and 3°F. A freezing night is all but certain in every month from October to May (a 90% chance or more). From July to August the chance of a 32°F night stays under 10% each month. In spring, June still brings one in 14% of years.

Warmth for growing adds up to 2,338 growing degree days a year (base 50°F), more than at 82% of the 33 North Dakota stations. 30% of them (690) have built up by the end of June, and July adds the most, 638. Precipitation totals 16.8 inches a year, most in June (3.3") and least in December (0.2"); May to September bring 69% of it.

The nearest other station, Garrison, ND, 26 miles north of Hazen, has a last frost 7 days earlier (May 14), a first frost 6 days later (September 26), a season 12 days longer.

The first measurable snow (0.1 inch or more) in Hazen usually arrives around October 31, and the last of the season around April 4. Those are the middle dates across the winters of 1991–2020 at Beulah 1 W, ND, 8.6 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 47 days after the last snow.

ZIP 58545 is 9 miles from Beulah 1 W, ND, which stands at 1,785 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 58545 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.