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Weather & Climate in Fern Forest, HI
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Fern Forest enjoys a temperate climate with an average annual temperature of 62°F (17°C). Winters average 59°F in January while summers reach 64°F in July / relatively mild seasonal variation. The area gets 330 sunny days per year, well above the U.S. average of 205 / making it one of the sunnier locations in the country. Annual precipitation totals 96.2 inches (wetter than the 38-inch national average). Air quality is rated Good with a median AQI of 24 / among the cleanest air in the country. The city sits at an elevation of 2,260 feet.
Temperature
59°F Jan (15°C)
64°F Jul (18°C)
| Annual Average | 61.7°F |
| 14% above US avg | |
| January Average | 59°F (15°C) |
| July Average | 64°F (18°C) |
| Sunny Days | 330 days/yr |
Geography
| Elevation | 2,260 ft (689 m) |
| Area | 12.5 sq mi (32.3 km²) |
| Population Density | 71/sq mi |
| Coordinates | 19.4647°N, 155.1324°W |
| Timezone | Pacific/Honolulu |
| County | Hawaii County County |
| Nearest Airport | Hilo International (ITO) 18 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 24.0 |
| Rating | Good |
Natural Hazard Risk
| Overall Risk | Relatively High |
| Risk Score | 98.5 / 100 |
| Social Vulnerability | 56.8 / 100 |
| Community Resilience | 56.7 / 100 |
Hazard Breakdown
| Tornado | Very Low |
| Hurricane | Relatively Low |
| Earthquake | Relatively High |
| Wildfire | Relatively High |
| Flood | Relatively High |
| Hail | Very Low |
| Strong Wind | Very Low |
| Heat Wave | No Rating |
| Winter Weather | Very Low |
| Lightning | Very High |
| Ice Storm | Very Low |
| Drought | Very Low |
| Cold Wave | Very Low |
| Landslide | Relatively Low |
| Coastal Flood | Relatively Low |
| Tsunami | Relatively Moderate |
| Volcano | Very High |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
14,129 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M6.9.
| May 4, 2018 | 18 km SSW of Leilani Estates, Hawaii | M6.9 | 21 km | 6 km |
| Feb 9, 2024 | 2 km SW of Pāhala, Hawaii | M5.9 | 49 km | 37 km |
| May 4, 2018 | 18 km SW of Leilani Estates, Hawaii | M5.7 | 19 km | 6 km |
| Apr 17, 1999 | 5 km N of P?hala, Hawaii | M5.6 | 44 km | 9 km |
| Mar 13, 2019 | 13 km SSE of Volcano, Hawaii | M5.5 | 17 km | 7 km |
| May 8, 1991 | Hawaii region, Hawaii | M5.5 | 115 km | 29 km |
| Jul 17, 2005 | 35 km SSE of Naalehu, Hawaii | M5.4 | 84 km | 32 km |
| Aug 14, 2007 | 15 km SSE of Fern Forest, Hawaii | M5.4 | 15 km | 9 km |
| Apr 14, 2019 | 20 km E of Kalaoa, Hawaii | M5.3 | 76 km | 13 km |
| Jul 15, 2005 | 50 km NNE of Pa‘auilo, Hawaii | M5.3 | 108 km | 15 km |
| Jun 5, 2013 | 54 km SE of P?hala, Hawaii | M5.3 | 62 km | 40 km |
| Jun 8, 2017 | 15 km S of Fern Forest, Hawaii | M5.3 | 15 km | 6 km |
| Feb 1, 1994 | 19 km ENE of P?hala, Hawaii | M5.3 | 29 km | 34 km |
| Dec 9, 1991 | 20 km SSW of Hawaiian Ocean View, Hawaii | M5.2 | 96 km | 44 km |
| Jun 28, 2015 | 12 km SSE of Volcano, Hawaii | M5.2 | 17 km | 8 km |
| Jul 5, 2021 | 12 km NNW of Kukuihaele, Hawaii | M5.2 | 99 km | 27 km |
| May 13, 2005 | 45 km ESE of Naalehu, Hawaii | M5.1 | 67 km | 43 km |
| Jun 30, 1997 | 14 km SSE of Fern Forest, Hawaii | M5.1 | 15 km | 8 km |
| Jun 27, 1998 | 51 km NW of Kalaoa, Hawaii | M5.1 | 142 km | 4 km |
| May 3, 2018 | 15 km SSE of Fern Forest, Hawaii | M5.1 | 15 km | 6 km |
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Hurricane History
8 hurricanes (Category 1+) recorded within 500 km since 1980. Strongest on record: Category 2.
| Year | Name | Category | Max Wind | Closest |
| 2024 | Hone | Category 1 | 86 mph | 153 km |
| 2020 | Douglas | Category 1 | 92 mph | 157 km |
| 2016 | Lester | Category 1 | 86 mph | 287 km |
| 2016 | Madeline | Category 1 | 81 mph | 236 km |
| 2014 | Iselle | Category 1 | 81 mph | 153 km |
| 2014 | Ana | Category 1 | 86 mph | 294 km |
| 2007 | Flossie | Category 2 | 104 mph | 235 km |
| 1986 | Estelle | Category 2 | 98 mph | 274 km |
Source: NOAA IBTrACS (Category 1+, 1980–2026).
Tornado History
7 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF2. Total: 4 injuries.
| Date | Rating | Distance | Path | Fatalities |
| Jan 28, 1971 | EF2 | 94 km | 1.0 mi | 0 |
| Mar 25, 1988 | EF1 | 39 km | 0.2 mi | 0 |
| Mar 20, 1980 | EF1 | 26 km | 1.0 mi | 0 |
| Feb 28, 2004 | EF0 | 48 km | 5.0 mi | 0 |
| Apr 3, 1986 | EF0 | 26 km | 0.2 mi | 0 |
| Nov 20, 1978 | EF0 | 52 km | 0.1 mi | 0 |
| Mar 19, 1955 | EF0 | 32 km | 0.1 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).
Tsunami History
10 tsunamis recorded within 500 km. Highest wave on record: 14.3 m (47 ft).
| Year | Location | Cause | Max Wave | Deaths | Distance |
| 1975 | HAWAII | Eruption + Earthquake | 14.3 m | 2 | 11 km |
| 1868 | HAWAII | Earthquake | 13.7 m | 77 | 65 km |
| 1869 | OFF COAST OF HAWAII | Unknown | 8.2 m | — | 61 km |
| 1919 | ALIKA, HAWAII | Explosion | 4.3 m | — | 85 km |
| 1951 | HAWAII | Earthquake | 3.6 m | — | 91 km |
| 1952 | HAWAII | Earthquake | 3.0 m | — | 43 km |
| 1908 | HAWAII | Earthquake | 1.2 m | — | 54 km |
| 2018 | HAWAII | Eruption | 0.4 m | — | 21 km |
| 1989 | HAWAII | Eruption + Earthquake | 0.3 m | — | 13 km |
| 2006 | HAWAII | Earthquake | 0.1 m | — | 96 km |
Source: NOAA/NCEI Historical Tsunami Database.
Nearby Volcanoes
5 volcanoes within 200 km. Closest: Kilauea (17 km).
| Name | Type | Elevation | Last Eruption | Distance |
| Kilauea | Shield | 1,222 m (4,009 ft) | 2018 | 17 km |
| Mauna Loa | Shield | 4,170 m (13,681 ft) | 1984 | 50 km |
| Mauna Kea | Shield | 4,205 m (13,796 ft) | -2460 | 53 km |
| Hualalai | Shield | 2,523 m (8,278 ft) | 1801 | 81 km |
| Haleakala | Shield | 3,055 m (10,023 ft) | 1750 | 181 km |
Source: Smithsonian Institution Global Volcanism Program (GVP).
Wildfire History
16 wildfires (100+ acres) recorded within 100 km. Largest: MANA ROAD FIRE (39,849 acres, 2021).
| Year | Name | Acres Burned | Distance |
| 2021 | MANA ROAD FIRE | 39,849 | 73 km |
| 2005 | LALAMILO | 18,960 | 84 km |
| 2018 | HIGHWAY 190 FIRE | 15,617 | 80 km |
| 2022 | LEILANI | 14,674 | 69 km |
| 2007 | WAIKOLOA FIRE | 8,791 | 81 km |
| 2018 | KEAUHOU RANCH BRUSH FIRE | 3,845 | 22 km |
| 2015 | KAWAIHAE FIRE | 3,743 | 95 km |
| 2003 | LUHI FIRE | 3,479 | 13 km |
| 2002 | KUPUKUPU | 2,479 | 14 km |
| 2003 | PANAU IKI | 1,926 | 16 km |
| 2016 | PUUWAAWAA MAKAI | 1,691 | 87 km |
| 2017 | WAIKAPUNA FIRE | 1,591 | 68 km |
| 1992 | KAWAIHAE | 1,567 | 94 km |
| 2000 | AHUWELA | 1,482 | 43 km |
| 2000 | UNNAMED | 1,178 | 41 km |
| 2000 | BROOMSEDGE | 1,011 | 18 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 59°F (15°C) | 13.0 in | Coldest |
| February | 66°F (19°C) | 10.9 in | |
| March | 66°F (19°C) | 6.5 in | |
| April | 66°F (19°C) | 9.2 in | |
| May | 67°F (20°C) | 7.0 in | |
| June | 68°F (20°C) | 4.3 in | Driest |
| July | 64°F (18°C) | 7.2 in | |
| August | 70°F (21°C) | 8.0 in | |
| September | 70°F (21°C) | 6.1 in | Warmest |
| October | 70°F (21°C) | 11.5 in | |
| November | 68°F (20°C) | 13.1 in | |
| December | 66°F (19°C) | 15.0 in | Wettest |
Fern Forest has a seasonal temperature swing of 12°F / from 59°F in January to 70°F in September. Total annual precipitation is 111.8 inches, with December being the wettest month (15.0") and June the driest (4.3").