USDA Hardiness Zone 12b
Frost Dates for 96793 — Wailuku, Hawaii
NOAA 1991–2020 normals from Kahului Airport, HI (51 ft), 5 miles east.
Updated
No night at or below 32°F was recorded at Kahului Airport, HI in 1991–2020, not even 36°F, so Wailuku has no frost dates to plan around; the coolest month, January, averages a low of 64°F.
- Winters with a freeze
- 0%
- Winters with 36°F
- 0%
- Coldest month low
- 64°F
- Hardiness zone
- 12b
32°F or below, 1991–2020
frost possible on leaves
average, January
55 to 60°F (12.8 to 15.6°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 Wailuku
Kahului Airport, HI, 5 miles east of Wailuku, 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 Kahului Airport, 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 96793 →Compare Wailuku with another place →
Weather by month in Wailuku
August is the warmest month at Kahului Airport, HI, averaging 90°F by day and 72°F at night; January is the coldest at 82°F and 64°F. Not one month recorded a 32°F night; the lowest monthly average low is 64°F.
Warmth for growing adds up to 9,898 growing degree days a year (base 50°F), more than at 89% of the 35 Hawaii stations. 46% of them (4,584) have built up by the end of June, and August adds the most, 964. Precipitation totals 16.1 inches a year, most in December (2.8") and least in June (0.2"); May to September bring 15% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 82 | 64 | 2.4 | 0% | 0 | 710 |
| Feb | 82 | 64 | 2.0 | 0% | 0 | 644 |
| Mar | 83 | 65 | 2.6 | 0% | 0 | 744 |
| Apr | 85 | 67 | 1.3 | 0% | 0 | 767 |
| May | 87 | 68 | 0.7 | 0% | 0 | 840 |
| Jun | 88 | 70 | 0.2 | 0% | 0 | 879 |
| Jul | 89 | 72 | 0.5 | 0% | 0 | 946 |
| Aug | 90 | 72 | 0.5 | 0% | 0 | 964 |
| Sep | 90 | 71 | 0.5 | 0% | 0 | 918 |
| Oct | 89 | 70 | 0.8 | 0% | 0 | 911 |
| Nov | 86 | 68 | 1.8 | 0% | 0 | 813 |
| Dec | 83 | 66 | 2.8 | 0% | 0 | 763 |
Monthly normals 1991–2020 at Kahului Airport, HI (51 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, Puukolii 457.1, HI, 11 miles west of Wailuku and 370 feet higher, has no 32°F night on record either, and the same coolest-month low, 64°F.
When it snows in Wailuku, Hawaii
Measurable snow is rare here: only 0 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Waiehu Camp 484, HI, 1.9 miles away, so there is no typical first-snow date to plan around.
Where these figures come from
ZIP 96793 is 5 miles from Kahului Airport, HI, which stands at 51 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 96793 in zone 12b, the band where the coldest night of the year averaged 55 to 60°F (12.8 to 15.6°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.