Hawaii

Naalehu, Hawaii Climate

NOAA 1991-2020 normals for Sea Mtn 12.15, 10.3 km from Naalehu

The warmest month is August, with an average high of 85°F; the coldest is February, with an average low of 65°F. A normal year brings 35.2 in of precipitation.

Temperature through the year

The normal daily high and low and the record for every date at Bradshaw_aaf/Hawaii (PHSF), since 2005. The line marks today.

Normal daily high and low temperature at Naalehu through the year, in °F, with the record for each date.20406080100JanFebMarAprMayJunJulAugSepOctNovDec
  • Normal low
  • Normal high
  • Record high
  • Record low

Normals for Sep 24

Normal high
84°F
Normal low
70°F
Record high
65°Fin 2021
Record low
35°Fin 2017
Chance of a wet day
28%
Daylight
12 h 04 min

Month by month

Averages for 1991-2020. Wet days have at least 0.01 inch of precipitation. Freeze nights have a low of 32°F or colder; degree days are on a 65°F base. Each month links to its own page.

MonthAvg highAvg lowRecord highRecord lowPrecipitationWet daysFreeze nightsHeating DDCooling DD
January79°F65°F66°F (2010)22°F (2014)3.52 in8.00.00223
February80°F65°F66°F (2024)21°F (2019)3.94 in8.00.00207
March80°F66°F66°F (2016)27°F (2021)4.03 in9.00.00239
April80°F67°F67°F (2020)28°F (2021)1.89 in7.60.00263
May82°F68°F67°F (2020)31°F (2015)1.41 in7.00.00307
June83°F70°F68°F (2010)31°F (2011)0.80 in5.80.00333
July84°F70°F69°F (2024)30°F (2008)1.87 in5.70.00371
August85°F71°F68°F (2024)31°F (2008)2.89 in5.30.00389
September84°F70°F67°F (2009)33°F (2011)2.77 in7.20.00365
October84°F70°F66°F (2022)32°F (2011)4.14 in9.40.00372
November82°F69°F64°F (2023)29°F (2007)3.96 in9.00.00312
December81°F67°F63°F (2015)26°F (2021)4.00 in7.50.00273
Year82°F68°F35.22 in90003,652

Precipitation

Rain and melted snow together. The chance of a wet day is the share of days with at least 0.01 inch of precipitation.

35.2 in in a normal year, most in October.

Chance of a wet day

The chance of at least 0.01 inch of precipitation on each date at Naalehu, in percent.010203040JanFebMarAprMayJunJulAugSepOctNovDec
  • Chance of a wet day

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Sea Mtn 12.15. A median date has an even chance of a later freeze in spring, or an earlier one in fall.

A freeze (32°F or colder) happens in only 0 percent of years at Sea Mtn 12.15, so there is no typical freeze season.

Frost dates, growing season and degree days

Humidity and comfort

NASA POWER reanalysis, 1991-2020, for the grid cell around Naalehu.

The muggiest month is August, when 96 percent of days are muggy or worse, with a mean dew point of 65°F or more.

MonthDew pointHumidityDryComfortableHumidMuggyOppressiveMiserable
January63°F78%0%11%64%25%0%0%
February63°F78%0%16%62%22%0%0%
March63°F78%0%9%63%27%0%0%
April64°F77%0%4%61%34%0%0%
May65°F78%0%1%40%58%1%0%
June66°F77%0%0%19%80%1%0%
July67°F78%0%0%8%83%9%0%
August68°F77%0%0%4%78%18%0%
September68°F78%0%0%4%79%17%0%
October68°F79%0%0%7%77%16%0%
November66°F79%0%1%21%72%5%0%
December65°F79%0%5%50%45%1%0%

Comfort is judged by the day's mean dew point: dry below 55°F, comfortable to 60°F, humid to 65°F, muggy to 70°F, oppressive to 75°F, miserable above.

Clouds

Average share of the sky covered, from satellite (CERES and GEWEX SRB) by way of NASA POWER, 1991-2020.

The clearest month is August, with the sky 52 percent covered on average; the cloudiest is April, at 61 percent.

Wind

The mean wind speed over the whole day, from the MERRA-2 reanalysis by way of NASA POWER. Gusts run well above it.

The windiest month is April, averaging 13.9 mph at 10 meters (33 feet) above the ground.

Daylight and sunshine

The longest day is Jun 13, with 13 h 17 min of daylight; the shortest is Dec 14, with 10 h 59 min.

Hours of daylight at Naalehu through the year.0510152025JanFebMarAprMayJunJulAugSepOctNovDec
  • Day length

Solar energy

Average daily sunshine reaching the ground on a flat surface, in kilowatt-hours per square meter, clouds included.

Sunrise and sunset calendar

How Hawaii County is running

NOAA NCEI Climate at a Glance, from the nClimGrid analysis of every station, updated early each month. A rank of 1 is the highest or lowest of all years since 1895.

August 2026 in Hawaii County: 68.2°F (+1.9 °F against 1991-2020), the 3rd warmest in 36 years on record.

August 2026 in Hawaii County: 19.56 in (+13.79 in against 1991-2020), the 2nd wettest in 36 years on record.

January to August 2026 in Hawaii County: 64.0°F (+1.1 °F against 1991-2020), the warmest in 36 years on record.

January to August 2026 in Hawaii County: 75.04 in (+34.37 in against 1991-2020), the 2nd wettest in 36 years on record.

Warmest August
68.7°F in 2019
Coolest August
64.6°F in 1998
Wettest August
25.24 in in 2018
Driest August
1.75 in in 2010

Every year since 1991

Each year's average temperature in Hawaii County against the 1991-2020 average, in °F, 1991 to 2025.-2-10+1+220002020NOAA NCEI Climate at a Glance

Hawaii climate and rankings

Month pages

The weather in Naalehu in each month, day by day.

What this means

A normal is the average of the thirty years 1991 to 2020, the period the World Meteorological Organization and NOAA use for comparison. It is an average, not a forecast: most days depart from it, and some by a long way.

A record is the highest or lowest value on the date in every year the station has reported, back to 2005. It rests on one station, so a neighbor a few miles away can hold different ones.

Cloud, humidity, wind and sunshine come from a reanalysis: a weather model run over the past with every observation fed in, averaged over a grid cell about 50 km across. It is consistent everywhere on Earth; it smooths local detail such as a lake shore or a valley.

More for this place

Nearby

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00518600 (Sea Mtn 12.15), public domain. Records: NOAA GHCN-Daily, station USW00021514, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus. Rankings: NOAA NCEI Climate at a Glance, public domain.