USDA Hardiness Zone 11a
Frost Dates for 96720 — Hilo, Hawaii
NOAA 1991–2020 normals from Hilo International Airport, HI (38 ft), 3 miles east.
Updated
No night at or below 32°F was recorded at Hilo International Airport, HI in 1991–2020, not even 36°F, so Hilo 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
- 11a
32°F or below, 1991–2020
frost possible on leaves
average, January
40 to 45°F (4.4 to 7.2°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 Hilo
Hilo International Airport, HI, 3 miles east of Hilo, 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 Hilo International 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 96720 →Compare Hilo with another place →
Weather by month in Hilo
August is the warmest month at Hilo International Airport, HI, averaging 83°F by day and 70°F at night; February is the coldest at 78°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 8,758 growing degree days a year (base 50°F), fewer than at 63% of the 35 Hawaii stations. 47% of them (4,114) have built up by the end of June, and August adds the most, 826. Precipitation totals 120.4 inches a year, most in November (14.4") and least in May (7.0"); May to September bring 36% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 79 | 64 | 7.9 | 0% | 0 | 663 |
| Feb | 78 | 64 | 10.2 | 0% | 0 | 595 |
| Mar | 79 | 65 | 12.7 | 0% | 0 | 677 |
| Apr | 79 | 66 | 9.4 | 0% | 0 | 677 |
| May | 81 | 67 | 7.0 | 0% | 0 | 744 |
| Jun | 82 | 69 | 7.3 | 0% | 0 | 758 |
| Jul | 83 | 70 | 9.2 | 0% | 0 | 817 |
| Aug | 83 | 70 | 11.3 | 0% | 0 | 826 |
| Sep | 83 | 70 | 8.7 | 0% | 0 | 797 |
| Oct | 82 | 69 | 10.2 | 0% | 0 | 797 |
| Nov | 80 | 68 | 14.4 | 0% | 0 | 719 |
| Dec | 79 | 66 | 12.1 | 0% | 0 | 690 |
Monthly normals 1991–2020 at Hilo International Airport, HI (38 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, Hilo 5 S, HI, 5 miles south of Hilo and 584 feet higher, has no 32°F night on record either, and a coolest-month low 3°F colder (61°F).
When it snows in Hilo, Hawaii
Measurable snow is rare here: only 0 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Waiakea Scd 88.2, HI, 4.4 miles away, so there is no typical first-snow date to plan around.
Where these figures come from
ZIP 96720 is 3 miles from Hilo International Airport, HI, which stands at 38 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 96720 in zone 11a, the band where the coldest night of the year averaged 40 to 45°F (4.4 to 7.2°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.