USDA Hardiness Zone 12a
Frost Dates for 96791 — Waialua, Hawaii
NOAA 1991–2020 normals from Poamoho Exp Fm 855.2, HI (722 ft), 4 miles southeast.
Updated
No night at or below 32°F was recorded at Poamoho Exp Fm 855.2, HI in 1991–2020, not even 36°F, so Waialua has no frost dates to plan around; the coolest month, February, averages a low of 62°F.
- Winters with a freeze
- 0%
- Winters with 36°F
- 0%
- Coldest month low
- 62°F
- Hardiness zone
- 12a
32°F or below, 1991–2020
frost possible on leaves
average, February
50 to 55°F (10.0 to 12.8°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 20 observed
NOAA normal
Frost risk by date in Waialua
Poamoho Exp Fm 855.2, HI, 4 miles southeast of Waialua, did not record a night at or below 32°F in 1991–2020. 36 of the 37 other Hawaii stations behind this site's ZIP pages recorded no 32°F night either.
Freeze probabilities 1991–2020 at Poamoho Exp Fm 855.2, HI, 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 96791 →Compare Waialua with another place →
Weather by month in Waialua
August is the warmest month at Poamoho Exp Fm 855.2, HI, averaging 86°F by day and 70°F at night; February is the coldest at 76°F and 62°F. Not one month recorded a 32°F night; the lowest monthly average low is 62°F.
Warmth for growing adds up to 8,503 growing degree days a year (base 50°F), fewer than at 71% of the 35 Hawaii stations. 45% of them (3,853) have built up by the end of June, and August adds the most, 863. Precipitation totals 33.0 inches a year, most in December (5.6") and least in July (1.1"); May to September bring 21% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 76 | 63 | 4.8 | 0% | 0 | 592 |
| Feb | 76 | 62 | 2.8 | 0% | 0 | 529 |
| Mar | 76 | 63 | 4.5 | 0% | 0 | 609 |
| Apr | 79 | 64 | 2.4 | 0% | 0 | 641 |
| May | 80 | 66 | 1.8 | 0% | 0 | 708 |
| Jun | 84 | 68 | 1.2 | 0% | 0 | 774 |
| Jul | 85 | 69 | 1.1 | 0% | 0 | 836 |
| Aug | 86 | 70 | 1.5 | 0% | 0 | 863 |
| Sep | 85 | 70 | 1.3 | 0% | 0 | 818 |
| Oct | 83 | 69 | 2.6 | 0% | 0 | 798 |
| Nov | 79 | 67 | 3.4 | 0% | 0 | 696 |
| Dec | 77 | 65 | 5.6 | 0% | 0 | 639 |
Monthly normals 1991–2020 at Poamoho Exp Fm 855.2, HI (722 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, Waimea Valley 892.2, HI, 7 miles northeast of Waialua and 681 feet lower, has no 32°F night on record either, and the same coolest-month low, 62°F.
When it snows in Waialua, Hawaii
Measurable snow is rare here: only 0 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Waimea Valley 892.2, HI, 6.9 miles away, so there is no typical first-snow date to plan around.
Where these figures come from
ZIP 96791 is 4 miles from Poamoho Exp Fm 855.2, HI, which stands at 722 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 96791 in zone 12a, the band where the coldest night of the year averaged 50 to 55°F (10.0 to 12.8°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.