USDA Hardiness Zone 12a
Frost Dates for 96797 — Waipahu, Hawaii
NOAA 1991–2020 normals from Ewa Beach Usgs 702.2, HI (5 ft), 6 miles south.
Updated
No night at or below 32°F was recorded at Ewa Beach Usgs 702.2, HI in 1991–2020, not even 36°F, so Waipahu has no frost dates to plan around; the coolest month, January, 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, January
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 Waipahu
Ewa Beach Usgs 702.2, HI, 6 miles south of Waipahu, 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 Ewa Beach Usgs 702.2, 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 96797 →Compare Waipahu with another place →
Weather by month in Waipahu
August is the warmest month at Ewa Beach Usgs 702.2, HI, averaging 87°F by day and 71°F at night; January is the coldest at 80°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 9,228 growing degree days a year (base 50°F), more than at 60% of the 35 Hawaii stations. 46% of them (4,266) have built up by the end of June, and August adds the most, 907. Precipitation totals 17.0 inches a year, most in March (2.7") and least in June (0.4"); May to September bring 21% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 80 | 62 | 1.8 | 0% | 0 | 651 |
| Feb | 80 | 63 | 1.7 | 0% | 0 | 601 |
| Mar | 81 | 64 | 2.7 | 0% | 0 | 687 |
| Apr | 82 | 66 | 0.8 | 0% | 0 | 722 |
| May | 84 | 67 | 1.0 | 0% | 0 | 784 |
| Jun | 86 | 69 | 0.4 | 0% | 0 | 822 |
| Jul | 87 | 71 | 0.5 | 0% | 0 | 885 |
| Aug | 87 | 71 | 0.8 | 0% | 0 | 907 |
| Sep | 87 | 70 | 0.8 | 0% | 0 | 848 |
| Oct | 86 | 69 | 1.7 | 0% | 0 | 848 |
| Nov | 84 | 67 | 2.2 | 0% | 0 | 758 |
| Dec | 81 | 65 | 2.6 | 0% | 0 | 718 |
Monthly normals 1991–2020 at Ewa Beach Usgs 702.2, HI (5 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, Upper Wahiawa 874.3, HI, 7 miles north of Waipahu and 1,001 feet higher, has no 32°F night on record either, and a coolest-month low 2°F colder (60°F).
When it snows in Waipahu, Hawaii
Measurable snow is rare here: only 0 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Ewa Beach Usgs 702.2, HI, 6.2 miles away, so there is no typical first-snow date to plan around.
Where these figures come from
ZIP 96797 is 6 miles from Ewa Beach Usgs 702.2, HI, which stands at 5 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station; its figures are presented in full for 96706 (Ewa Beach). The 2023 USDA Plant Hardiness Zone Map lists ZIP 96797 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.