USDA Hardiness Zone 6b
Frost Dates for 85933 — Overgaard, Arizona
NOAA 1991–2020 normals from Heber (Black Mesa) Rs, AZ (6,590 ft), 2 miles west.
Updated
In Overgaard, the last spring frost (32°F) is around May 23 in half of years and has passed by June 6 in nine years out of ten. The first fall frost comes around October 5, as early as September 24 one year in ten, leaving a typical freeze-free season of 135 days (NOAA, Heber (Black Mesa) Rs, AZ).
- Last spring frost
- May 23
- First fall frost
- October 5
- Growing season
- 135 days
- Hardiness zone
- 6b
50% probability
50% probability
freeze-free, 50%
-5 to 0°F (-20.6 to -17.8°C) coldest night
- First snow
- December 16
- Last snow
- February 28
- Winters with snow
- 93%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
28 of 30 observed
NOAA normal
Frost risk by date in Overgaard
Half of springs at Heber (Black Mesa) Rs, AZ see their last 32°F night by May 23; only one in ten is past it by May 6, and one in ten still has one after June 6. Planting tender crops after May 30 leaves a 30% risk of a frost on them, after June 2 20%, and after June 6 10%. The 14 days between the even-odds date and the one-in-ten date is narrower than at 95% of the 98 Arizona stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 5 in half of years, as early as September 24 one year in ten, and holds off past October 19 one year in ten. A hard freeze of 28°F follows 11 days later, around October 16; in spring the one-in-ten date for 28°F is May 28, 9 days before the 32°F one. The freeze-free season lasts 135 days in a typical year, shorter than at 95% of the 98 Arizona stations; it reaches 155 days one year in ten and falls short of 114 one year in ten. On average 170 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 June 3, and return around September 27. Severe cold of 16°F or below comes every winter, usually between November 20 and March 10.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 22 | May 26 | May 30 | May 31 | Jun 3 | Jun 5 | Jun 8 | Jun 12 | Jun 18 |
| 32°F | May 6 | May 11 | May 16 | May 20 | May 23 | May 27 | May 30 | Jun 2 | Jun 6 |
| 28°F | Apr 23 | Apr 28 | May 1 | May 5 | May 8 | May 12 | May 16 | May 21 | May 28 |
| 24°F | Apr 3 | Apr 9 | Apr 15 | Apr 19 | Apr 23 | Apr 27 | May 1 | May 5 | May 11 |
| 20°F | Mar 11 | Mar 18 | Mar 25 | Mar 30 | Apr 3 | Apr 8 | Apr 12 | Apr 18 | Apr 24 |
| 16°F | Feb 19 | Feb 27 | Mar 3 | Mar 6 | Mar 10 | Mar 14 | Mar 21 | Mar 30 | Apr 9 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 16 | Sep 19 | Sep 22 | Sep 25 | Sep 27 | Sep 30 | Oct 2 | Oct 4 | Oct 9 |
| 32°F | Sep 24 | Sep 28 | Oct 1 | Oct 3 | Oct 5 | Oct 8 | Oct 11 | Oct 15 | Oct 19 |
| 28°F | Oct 1 | Oct 5 | Oct 9 | Oct 13 | Oct 16 | Oct 19 | Oct 22 | Oct 26 | Nov 1 |
| 24°F | Oct 11 | Oct 17 | Oct 20 | Oct 24 | Oct 27 | Oct 30 | Nov 2 | Nov 5 | Nov 10 |
| 20°F | Oct 22 | Oct 29 | Nov 1 | Nov 4 | Nov 7 | Nov 11 | Nov 14 | Nov 18 | Nov 23 |
| 16°F | Nov 4 | Nov 9 | Nov 13 | Nov 17 | Nov 20 | Nov 22 | Nov 26 | Nov 29 | Dec 3 |
Freeze probabilities 1991–2020 at Heber (Black Mesa) Rs, AZ, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.
Frost risk on any date in 85933 →Compare Overgaard with another place →
Weather by month in Overgaard
July is the warmest month at Heber (Black Mesa) Rs, AZ, averaging 83°F by day and 56°F at night; January is the coldest at 46°F and 20°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 25% of years.
Warmth for growing adds up to 2,298 growing degree days a year (base 50°F), fewer than at 95% of the 102 Arizona stations. 30% of them (680) have built up by the end of June, and July adds the most, 601. Precipitation totals 18.4 inches a year, most in August (3.0") and least in June (0.5"); May to September bring 47% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 46 | 20 | 1.7 | 100% | 29 | 0 |
| Feb | 50 | 23 | 1.7 | 100% | 25 | 1 |
| Mar | 57 | 28 | 1.4 | 100% | 24 | 9 |
| Apr | 64 | 32 | 0.7 | 100% | 18 | 43 |
| May | 71 | 39 | 0.6 | 95% | 7 | 182 |
| Jun | 82 | 48 | 0.5 | 25% | 1 | 444 |
| Jul | 83 | 56 | 2.7 | 0% | 0 | 601 |
| Aug | 81 | 55 | 3.0 | 0% | 0 | 547 |
| Sep | 76 | 48 | 1.8 | 27% | 1 | 348 |
| Oct | 67 | 36 | 1.2 | 99% | 12 | 108 |
| Nov | 55 | 27 | 1.2 | 100% | 24 | 14 |
| Dec | 46 | 20 | 1.9 | 100% | 29 | 1 |
Monthly normals 1991–2020 at Heber (Black Mesa) Rs, AZ (6,590 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.
Compared with the next station
The nearest other station, Snowflake, AZ, 26 miles east of Overgaard and 948 feet lower, has a last frost 12 days earlier (May 11), a first frost 5 days later (October 10), a season 14 days longer.
When it snows in Overgaard, Arizona
The first measurable snow (0.1 inch or more) in Overgaard usually arrives around December 16, and the last of the season around February 28. Those are the middle dates across the winters of 1991–2020 at Heber (Black Mesa) Rs, AZ, 2.1 miles away: half of years saw snow earlier, half later. Snow fell in 93% of those winters. The last 32°F night of spring typically comes 84 days after the last snow.
Planting calendar for 85933
| When | What to do |
|---|---|
| March 14 – March 28 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 28 – April 11 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 25 – May 9 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 23 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 13 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 21 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 5 onward | Plant garlic, mulch beds, lift tender bulbsGarlic wants a cold spell; bare soil loses structure over winter. |
The weeks before and after the 50% dates are general rules of thumb, not NOAA figures; a seed packet gives the timing for each variety.
Where these figures come from
ZIP 85933 is 2 miles from Heber (Black Mesa) Rs, AZ, which stands at 6,590 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 85933 in zone 6b, the band where the coldest night of the year averaged -5 to 0°F (-20.6 to -17.8°C) over 1991–2020; a zone describes winter lows, not frost dates.
Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.
Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.