PlainClimate
NOAA 1991–2020 normals Census-designated place · exact match 2 NOAA stations · Multiple stations mapped

Hilo, HI Climate: Temperature & Rain by Month

Annual temperature and rainfall from NOAA NCEI's 1991–2020 normals →; comfort score computed by PlainClimate

30-year climate normals (1991-2020) from Hilo's primary NOAA station, HILO INTL AP - 2 stations mapped to the area.

The climate verdict for Hilo

Warm-season cooling demand defines Hilo, Hawaii, running at more than twice its heating total. The NOAA normal records an annual average of 74°F. August is the warmest month at 77°F and February the coldest at 71°F.

74°F
annual average temperature (NOAA normal)
120.4"
precipitation, annual total

Hilo: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.

Normals record plate

Sheet USW00021504 · Hilo, HI 74°F mean · 120.4" precip

TEMP-HOT · RANK-WARM · PHOTO-FINISH · PRCP-WET · SWING-NARROW · COMF-UNK · LOAD-COOL · STN-MULTI · BOOK-FULL

Nearest mean-temperature peer: Kilauea, HI ( -0.1 °F mean)

Instrument codes from this station's NOAA 1991–2020 normals, mean temperature, corpus warmth rank, photo-finish peer station, precipitation band, seasonal swing, comfort composite, degree-day load, and field book, not a livability rating.

Mean-temperature neighbourhood

Nationwide NOAA normal poles and nearest peers, not a reprint of every HI station list.

Hilo sits in Hawaii, the #2 hottest U.S. state at 72.4°F statewide annual average - see all 50 hottest states ranked by NOAA normals

Climate Living Index · Hilo

Hilo: 60/100 · grade C

Hilo publishes 4 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals · NOAA hourly normals); 2 missing weights rescale to 100.

C
60/100Climate Living Index

PlainClimate-derived for Hilo, not an official NOAA rating. Breakpoints and limits.

Hilo Living Index dimension scores
DimensionStation valueScore
Normal heat + freeze calendar 0 calendar days 100/100 · A
Annual temperature balance 74.0°F · 6.5° from 67.5°F 80/100 · B
Summer moisture balance 68.4°F mean dew point 20/100 · F
Precipitation balance 120.4 in · 85.4 from 35 in 0/100 · F

Hilo · 2026-08-04 · NOAA NCEI Climate Normals · method .

Hilo stays in the tropical Köppen band: Af

Every month stays warm (coldest ≥18°C) and the driest month still averages ≥60 mm: tropical rainforest (Af). Class Af is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: tropical, specifically tropical rainforest.

Köppen code
Af
Group
Tropical
Warmest month
76.6°F
Coldest month
71.2°F

Source: official public datasets monthly normals (1991–2020) at the city’s primary station. This is a station classification, not a mapped regional consensus.

National standing · cooling-led station

Where Hilo sits across the climate record

Three NOAA fields for Hilo's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.

Annual temperature
Top 2% warmest
Among 6,861 stations, Hilo sits in the warmer third of annual means.
Annual precipitation
Top 1% wettest
Hilo's annual total ranks in the wetter third of 6,352 measured normals.
Seasonal temperature swing
Narrower than 100%
Warmest-to-coldest month gap for Hilo is compact versus 6,861 complete station-years.

Hilo's measured station temperature trend

Methodology

Across 38 complete annual observations from 1983 to 2025, HILO INTL AP warmed at a fitted rate of 0.19°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.

Hilo fitted annual mean temperature change, 1983-2025 Fitted station-temperature change from 1983 to 2025, relative to the fitted first year. The linear trend warmed at 0.19 °C per decade. -0.2°C +0.0°C +0.2°C +0.4°C +0.6°C +0.8°C +1.0°C 20002020
  • Hilo primary station fitted change +0.19 °C/decade
Source: NOAA GHCN-M v4, quality-controlled monthly mean temperature. PlainClimate fits ordinary least squares over complete calendar years; minimum 30 years, record must reach 2015 or later.

Monthly Temperatures

Average daily high and low temperatures by month

Month Avg High Avg Low Mean
January 79°F (26°C) 64°F (18°C) 71°F (22°C)
February 78°F (26°C) 64°F (18°C) 71°F (22°C)
March 79°F (26°C) 65°F (18°C) 72°F (22°C)
April 79°F (26°C) 66°F (19°C) 73°F (23°C)
May 81°F (27°C) 67°F (20°C) 74°F (23°C)
June 82°F (28°C) 69°F (20°C) 75°F (24°C)
July 83°F (28°C) 70°F (21°C) 76°F (25°C)
August 83°F (28°C) 70°F (21°C) 77°F (25°C)
September 83°F (29°C) 70°F (21°C) 77°F (25°C)
October 82°F (28°C) 69°F (21°C) 76°F (24°C)
November 80°F (27°C) 68°F (20°C) 74°F (23°C)
December 79°F (26°C) 66°F (19°C) 72°F (22°C)

The year, day by day

The calendar barely moves in Hilo: no date carries a normal high of 90°F or a normal low at freezing. The year runs between 64°F near January 23 and 83°F near September 14.

Normal daily high and low temperature for Hilo, January through December Peaks 83°F around September 14. Bottoms 64°F around January 23. 55 60 65 70 75 80 85 90 JanFebMarAprMayJunJulAugSepOctNovDec
Normal daily high and low across the calendar year. NOAA 1991–2020 daily normals, HILO INTL AP.

No freezing date

Not one calendar date in the 1991–2020 record carries a normal low at or below 32°F. The coldest normal low of the year is 64°F around January 23.

Where the wet dates fall

The likeliest wet date is August 3, when 88% of years recorded at least a hundredth of an inch. The driest is January 19 at 52%. Summed across the calendar, that is about 273 wet dates a year.

The widest day

January 23 carries the biggest normal gap between afternoon and dawn, 15°F between the normal high and the normal low.

Look up any date

Any date's 1991–2020 normal for Hilo.

Where Hilo Stands Nationally

This is one of the wettest normals climates ranked: about 120 inches of precipitation in a normal year, a total fewer than one station in ten surpasses.

Among the steadiest day-night climates ranked: even the widest normal daily swing holds to roughly 15°F.

Hilo earns 2 nationally notable standings (outer quintiles) against 6,860 NOAA 1991–2020 normals stations; only those extremes render.

Monthly Precipitation

Average monthly rainfall

January 7.9"

15.7 days with precipitation

February 10.2"

16.6 days with precipitation

March 12.7"

21.8 days with precipitation

April 9.4"

24.5 days with precipitation

May 7.0"

22.9 days with precipitation

June 7.3"

25.4 days with precipitation

July 9.2"

26.6 days with precipitation

August 11.3"

27.2 days with precipitation

September 8.7"

23.3 days with precipitation

October 10.2"

23.4 days with precipitation

November 14.4"

23.3 days with precipitation

December 12.1"

22.3 days with precipitation

Hilo spreads its precipitation across the year

Neither half of the year dominates here: June through August take 23% of the annual total and December through February 25%, with neither reaching the 35% that would mark a distinct wet season. Hilo has no dry season to plan around, though it does carry an unusually narrow 5.4°F seasonal spread.

The gap between the wettest and driest month still matters: November averages 14.4" and May 7.0". The three wettest months together take 33% of the year, against the 25% a perfectly flat distribution would give them.

Shares are computed from this station's own 1991-2020 monthly precipitation normals. "Spread across the year" means neither the June-August nor the December-February share reaches 35%; it describes an average year, not the variability of any single one.

When it rains in Hilo, it arrives in quantity

120.4" of precipitation falls across only about 273 wet days here, averaging 0.44 inches each. Fewer days carry more water: the year's total is delivered in comparatively heavy events rather than persistent damp.

Days with measurable precipitation
about 273 a year, 75% of all days
Average depth per wet day
0.44 inches
Most wet days
August, about 27
Fewest wet days
January, about 16

A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year, and a per-day average is not a forecast of any individual storm.

Frost Dates & Growing Season

First Fall Freeze

N/A

50% probability date

Last Spring Freeze

N/A

50% probability date

Heating & Cooling Degree Days

Annual totals indicate energy demand for heating and cooling

Heating Degree Days

0

Higher = more heating needed

Cooling Degree Days

3,283

Higher = more cooling needed

Warmest Month

August

Coldest Month

February

Humidity & Wind

Monthly averages from hourly observations

Month Humidity Wind (mph)
January 74% 6.9
February 75% 7.1
March 78% 6.8
April 77% 6.7
May 76% 6.4
June 77% 6.5
July 79% 6.3
August 78% 6.4
September 77% 6.2
October 80% 6.1
November 80% 6.3
December 76% 6.4

Nationwide similar cities

Other rankable U.S. places outside HI closest to Hilo on two NOAA annual-normal axes (mean temperature and annual precipitation). Chip rows use distinct link sets.

Closest by average temperature

Nearest out-of-state peers by annual mean temperature (74°F here).

Closest by annual precipitation

Nearest out-of-state peers by annual precipitation (120.4" here), excluding temperature-peer places.

Hawaii climate overview →

Data-derived climate profile

How Hilo's climate pattern fits together

cooling led · wet · low swing

Warm-season load persists through a relatively even calendar in Hilo. Cooling totals 3,283 degree days, more than double the 0 heating measure, and the 5.4°F seasonal range is compact rather than sharply divided.

Warm-season demand is paired with a wet annual normal: 120.4 inches of precipitation at Hilo. Snowfall is not added to the interpretation because its annual value is missing. The month-by-month bars distinguish a concentrated wet season from moisture spread across the calendar.

Hilo's 5.4°F seasonal spread is compact even though precipitation is abundant. August and February mark the typical warm and cold ends of the calendar. The annual average is 74°F. Temperature is relatively steady; the monthly rows show how rain and snow observations vary across the calendar.

A frost-free growing-season length is not available for Hilo. That missing field is kept separate from the observed temperature and precipitation record rather than filled from a regional estimate.

These labels group NOAA 1991-2020 normals from Hilo's primary station, so the summer figures are a thirty-year average rather than a ceiling: individual years have run hotter and will again. For Hilo that means a descriptive range only — not an official NOAA classification and not a prediction for next summer.

Questions about Hilo's climate

How much rain does Hilo get?
Hilo receives 120.4 inches of precipitation. Based on NOAA 30-year climate normals (1991-2020).
How much energy does heating and cooling require in Hilo?
Hilo has 0 heating degree days and 3,283 cooling degree days annually, a cooling-dominated climate. Degree-day definitions: reading weather data.

Data Sources

Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Hilo's primary station: HILO INTL AP (USW00021504). 2 NOAA stations are mapped to the Hilo area; the primary station's record is used for consistency. For informational purposes only.

Place identity: U.S. Census Bureau 2024 Gazetteer places. The 2024 Census Gazetteer identifies the exact name-and-state match as a census-designated place (GEOID 1514650), not an incorporated municipality. Match rule for Hilo: exact normalized name + state only, no fuzzy expansion, so nearby differently spelled facilities stay unmatched.

Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainClimate

On this page every temperature, precipitation, and derived score for Hilo comes from its primary NOAA station record. No figure on this page is typed in by an editor - each value is rendered from NOAA 1991-2020 U.S. Climate Normals. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 1991–2020 normals.