Frost Dates for 87420 — Shiprock, New Mexico

Half of springs at Teec Nos Pos, AZ see their last 32°F night by April 11; only one in ten is past it by March 24, and one in ten still has one after May 2. Planting tender crops after April 19 leaves a 30% risk of a frost on them, after April 24 20%, and after May 2 10%. The 21 days between the even-odds date and the one-in-ten date is wider than at 96% of the 70 New Mexico stations behind this site's ZIP pages, so a fixed calendar date is a gamble here.

In fall the first 32°F night comes by November 1 in half of years, as early as October 16 one year in ten, and holds off past November 12 one year in ten. A hard freeze of 28°F follows 8 days later, around November 9; in spring the one-in-ten date for 28°F is April 13, 19 days before the 32°F one. The freeze-free season lasts 200 days in a typical year, longer than at 77% of the 70 New Mexico stations; it reaches 222 days one year in ten and falls short of 173 one year in ten. On average 117 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 16 days longer, to about April 27, and return around October 21. Severe cold of 16°F or below comes in 99% of winters, usually between December 9 and January 29.

July is the warmest month at Teec Nos Pos, AZ, averaging 95°F by day and 67°F at night; January is the coldest at 45°F and 24°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 74% of years and May still brings one in 13% of years.

Warmth for growing adds up to 4,243 growing degree days a year (base 50°F), more than at 69% of the 70 New Mexico stations. 36% of them (1,515) have built up by the end of June, and July adds the most, 959.

The nearest other station, Fruitland, NM, 25 miles east of Shiprock and 160 feet lower, has a last frost 31 days later (May 12), a first frost 28 days earlier (October 4), a season 57 days shorter.

The first measurable snow (0.1 inch or more) in Shiprock usually arrives around December 4, and the last of the season around February 25. Those are the middle dates across the winters of 1991–2020 at Fruitland, NM, 25 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 45 days after the last snow.

ZIP 87420 is 20 miles from Teec Nos Pos, AZ, which stands at 5,290 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 87420 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.