Frost Dates for 87325 — Tohatchi, New Mexico

Half of springs at Window Rock Airport, AZ see their last 32°F night by May 29; only one in ten is past it by May 12, and one in ten still has one after June 10. Planting tender crops after June 2 leaves a 30% risk of a frost on them, after June 6 20%, and after June 10 10%. The 12 days between the even-odds date and the one-in-ten date is narrower than at 93% of the 70 New Mexico stations behind this site's ZIP pages.

In fall the first 32°F night comes by September 28 in half of years, as early as September 16 one year in ten, and holds off past October 8 one year in ten. A hard freeze of 28°F follows 6 days later, around October 4; in spring the one-in-ten date for 28°F is June 1, 9 days before the 32°F one. The freeze-free season lasts 121 days in a typical year, shorter than at 90% of the 70 New Mexico stations; it reaches 140 days one year in ten and falls short of 104 one year in ten. On average 196 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 June 8, and return around September 20. Severe cold of 16°F or below comes every winter, usually between November 4 and April 1.

July is the warmest month at Window Rock Airport, AZ, averaging 88°F by day and 55°F at night; December is the coldest at 46°F and 14°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 38% of years.

Warmth for growing adds up to 2,321 growing degree days a year (base 50°F), fewer than at 87% of the 70 New Mexico stations. 29% of them (682) have built up by the end of June, and July adds the most, 668. Precipitation totals 11.5 inches a year, most in August (1.9") and least in June (0.3"); May to September bring 51% of it.

The nearest other station, Gallup Sand & Gravel, NM, 33 miles south of Tohatchi and 162 feet lower, has a last frost 18 days earlier (May 11), a first frost 9 days later (October 7), a season 27 days longer.

The first measurable snow (0.1 inch or more) in Tohatchi usually arrives around November 28, and the last of the season around April 10. Those are the middle dates across the winters of 1991–2020 at Gallup Sand & Gravel, NM, 32.8 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 49 days after the last snow.

ZIP 87325 is 33 miles from Window Rock Airport, AZ, which stands at 6,739 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. That is farther than 25 miles, so local frost can differ noticeably from these figures. 4 other ZIP codes share the station; its figures are presented in full for 86504 (Fort Defiance). The 2023 USDA Plant Hardiness Zone Map lists ZIP 87325 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.