USDA Hardiness Zone 9b
Frost Dates for 86429 — Bullhead City, Arizona
NOAA 1991–2020 normals from Laughlin, NV (605 ft), 2 miles west.
Updated
A freeze (32°F) reaches Bullhead City in 61% of winters. When it does, the first fall frost comes around December 24 and the last spring frost around January 5; after February 13 the chance of another is under 6%.
- Last spring frost
- January 5
- First fall frost
- December 24
- Winters with a freeze
- 61%
- Hardiness zone
- 9b
50%, in freezing years
50%, in freezing years
32°F or below, 1991–2020
25 to 30°F (-3.9 to -1.1°C) coldest night
- First snow
- Rare
- Last snow
- Rare
- Winters with snow
- 0%
- Snow per year
- 0"
median, 1991–2020
median, 1991–2020
0 of 30 observed
NOAA normal
Frost risk by date in Bullhead City
In the 61% of winters that bring a 32°F night, half of springs at Laughlin, NV see their last 32°F night by January 5; only one in ten is past it by December 11, and one in ten still has one after February 13. Counting the winters with no freeze at all, the risk of a 32°F night after February 13 is under 6% and after January 5 30%. The 39 days between the even-odds date and the one-in-ten date is wider than at 98% of the 98 Arizona 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 December 24 in half of years, as early as December 3 one year in ten, and holds off past February 1 one year in ten. A hard freeze of 28°F is less common: it came in 15% of winters. The freeze-free season lasts 354 days in a typical year, longer than at 96% of the 98 Arizona stations; it reaches 365 days one year in ten and falls short of 317 one year in ten. On average 3 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 28 days longer, to about February 2, and return around December 13. No night reached 24°F in 1991–2020.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F98% of yrs | Dec 31 | Jan 8 | Jan 18 | Jan 27 | Feb 2 | Feb 9 | Feb 16 | Feb 23 | Mar 3 |
| 32°F61% of yrs | Dec 11 | Dec 18 | Dec 26 | Dec 31 | Jan 5 | Jan 11 | Jan 22 | Feb 2 | Feb 13 |
| 28°F15% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F98% of yrs | Nov 24 | Nov 30 | Dec 3 | Dec 8 | Dec 13 | Dec 17 | Dec 22 | Dec 28 | Jan 5 |
| 32°F61% of yrs | Dec 3 | Dec 9 | Dec 14 | Dec 19 | Dec 24 | Dec 30 | Jan 3 | Jan 12 | Feb 1 |
| 28°F15% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Laughlin, NV, 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 86429 →Compare Bullhead City with another place →
Weather by month in Bullhead City
July is the warmest month at Laughlin, NV, averaging 110°F by day and 82°F at night; December is the coldest at 64°F and 44°F. From March to November the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 13% of years.
Warmth for growing adds up to 8,869 growing degree days a year (base 50°F), more than at 92% of the 102 Arizona stations. 41% of them (3,638) have built up by the end of June, and July adds the most, 1,421. Precipitation totals 5.3 inches a year, most in February (1.2") and least in May (0.0"); May to September bring 17% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 65 | 45 | 1.0 | 27% | 1 | 159 |
| Feb | 69 | 47 | 1.2 | 13% | <1 | 229 |
| Mar | 77 | 51 | 0.8 | 0% | 0 | 444 |
| Apr | 86 | 57 | 0.2 | 0% | 0 | 647 |
| May | 95 | 66 | 0.0 | 0% | 0 | 956 |
| Jun | 106 | 75 | 0.0 | 0% | 0 | 1203 |
| Jul | 110 | 82 | 0.2 | 0% | 0 | 1421 |
| Aug | 108 | 81 | 0.4 | 0% | 0 | 1390 |
| Sep | 102 | 74 | 0.3 | 0% | 0 | 1136 |
| Oct | 89 | 61 | 0.3 | 0% | 0 | 775 |
| Nov | 74 | 51 | 0.3 | 4% | <1 | 373 |
| Dec | 64 | 44 | 0.6 | 36% | 1 | 136 |
Monthly normals 1991–2020 at Laughlin, NV (605 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, Bullhead City, AZ, 3 miles southwest of Bullhead City, has a last frost 1 day earlier (January 4), a first frost 1 day earlier (December 23), a season 2 days longer.
When it snows in Bullhead City, Arizona
Measurable snow is rare here: only 0 of 30 winters from 1991 to 2020 recorded 0.1 inch or more at Laughlin, NV, 1.9 miles away, so there is no typical first-snow date to plan around.
Where these figures come from
ZIP 86429 is 2 miles from Laughlin, NV, which stands at 605 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 86429 in zone 9b, the band where the coldest night of the year averaged 25 to 30°F (-3.9 to -1.1°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.