Frost dates / Arizona / Sierra Vista

Frost dates in Sierra Vista, AZ

The station on this page is SIERRA VISTA, AZ US (USC00027880), 2.8 miles from the city point. Population in the Census 2024 estimate is 44,710.

Zone 8bUSDA average annual extreme minimum 15°F to 20°F, from ZIP 85613 (6.2 miles from the city point used on this page).

Median last 32°F is April 5. Median first 32°F is November 9. The 50% growing-season length is 216 days. The green band runs from the median last frost to the median first frost. Thin ticks mark the 10%, 50%, and 90% dates.

Outside the median season Growing seasonTicks: 10%, 50%, and 90%

Last 32°F in spring

NCEI’s probability is the chance the last spring minimum of 32°F or lower occurs on or after the date.

Probability	Date	How to read it
90%	March 15	Earlier date. A last 32°F on or after this day is common.
50%	April 5	Median.
10%	April 21	Later date. A last 32°F on or after this day is uncommon.

First 32°F in fall

NCEI’s probability is the chance the first autumn minimum of 32°F or lower occurs on or before the date.

Probability	Date	How to read it
10%	October 23	Earlier date. A first 32°F on or before this day is uncommon.
50%	November 9	Median.
90%	November 23	Later date. A first 32°F on or before this day is common.

32°F growing-season length

Days between the last spring 32°F and the first autumn 32°F. The figure is a length the season meets or exceeds at that probability, from NCEI, not a subtraction done on this site.

Probability the season is at least this long	Days
10%	239
50%	216
90%	194

28°F threshold

	10%	50%	90%
Last, on or after	April 5	March 15	February 21
First, on or before	November 4	November 21	December 5
Season at least	276 days	248 days	220 days

36°F threshold

	10%	50%	90%
Last, on or after	May 4	April 20	April 5
First, on or before	October 15	October 30	November 12
Season at least	211 days	191 days	171 days

Station SIERRA VISTA, AZ US (USC00027880). Completeness flag R, 19 years used for the 32°F dates. NCEI’s annual probability of at least one day at or below 32°F is 100%. Freeze dates are conditional on that threshold occurring. Elevation 1403.9 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.

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Sierra Vista, AZ

Zone 8bAverage annual extreme minimum 15°F to 20°F

Outside the median season Growing seasonTicks: 10%, 50%, and 90%

Arizona. Nearest qualified station: SIERRA VISTA, AZ US (USC00027880), 2.8 miles. Median last 32°F April 5. Median first 32°F November 9. The 50% growing-season length is 216 days.

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32°F probabilities at this station

	10%	50%	90%
Last 32°F on or after	April 21	April 5	March 15
First 32°F on or before	October 23	November 9	November 23

Column order matches the NCEI file: for the last freeze, 10% is the later date and 90% is the earlier date. How to read the probabilities.

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Planting calendar

Frost dates for Arizona are above. Planting windows appear for states with a cited extension guide. The fall and seed tools use the numbers you enter and the station dates.

Date checks use your device’s calendar and appear after the page loads.