Hilo, Hawaii climate: Normal weather by month, frost dates and records
Hilo's normal year runs from 64°F February nights to 83°F August afternoons, with 120.4 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 23.3°C, February lows of 18°C, August highs of 28°C, 3,058 mm of precipitation a year.
- NOAA stationHilo International Airport 87
- Station IDUSW00021504
- Location19.72°N 155.05°W
- Elevation38 ft (12 m)
- Population (census place)48,223
On October 23, the normal high in Hilo is 82°F and the normal low 69°F, and the chance of measurable rain or snow is 77%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Hilo.
- Jan 79° 64°
- Feb 78° 64°
- Mar 79° 65°
- Apr 79° 66°
- May 81° 67°
- Jun 82° 69°
- Jul 83° 70°
- Aug 83° 70°
- Sep 83° 70°
- Oct 82° 69°
- Nov 80° 68°
- Dec 79° 66°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Hilo each month?
August is the warmest month, with normal highs of 83°F; February the coldest, with normal lows of 64°F. The most precipitation falls in November (14.39 in), the least in May (6.99 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 79°F | 64°F | 71.4°F | 7.86 | 16 | <1 | <1 | 11 h |
| February | 78°F | 64°F | 71.2°F | 10.22 | 17 | <1 | <1 | 11 h 30 min |
| March | 79°F | 65°F | 71.9°F | 12.68 | 22 | <1 | <1 | 12 h |
| April | 79°F | 66°F | 72.5°F | 9.40 | 25 | <1 | <1 | 12 h 30 min |
| May | 81°F | 67°F | 74.0°F | 6.99 | 23 | <1 | <1 | 13 h |
| June | 82°F | 69°F | 75.2°F | 7.30 | 25 | <1 | <1 | 13 h 20 min |
| July | 83°F | 70°F | 76.3°F | 9.24 | 27 | <1 | <1 | 13 h 10 min |
| August | 83°F | 70°F | 76.6°F | 11.30 | 27 | <1 | <1 | 12 h 50 min |
| September | 83°F | 70°F | 76.5°F | 8.70 | 23 | 1 | <1 | 12 h 20 min |
| October | 82°F | 69°F | 75.7°F | 10.24 | 23 | <1 | <1 | 11 h 40 min |
| November | 80°F | 68°F | 74.0°F | 14.39 | 23 | <1 | <1 | 11 h 10 min |
| December | 79°F | 66°F | 72.2°F | 12.07 | 22 | <1 | <1 | 11 h |
| Year (annual) | 81°F | 67°F | 74.0°F | 120.39 | 273 | 2 | <1 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 26°C | 18°C | 21.9°C | 200 mm |
| February | 26°C | 18°C | 21.8°C | 260 mm |
| March | 26°C | 18°C | 22.2°C | 322 mm |
| April | 26°C | 19°C | 22.5°C | 239 mm |
| May | 27°C | 20°C | 23.3°C | 178 mm |
| June | 28°C | 20°C | 24.0°C | 185 mm |
| July | 28°C | 21°C | 24.6°C | 235 mm |
| August | 28°C | 21°C | 24.8°C | 287 mm |
| September | 29°C | 21°C | 24.7°C | 221 mm |
| October | 28°C | 21°C | 24.3°C | 260 mm |
| November | 27°C | 20°C | 23.3°C | 366 mm |
| December | 26°C | 19°C | 22.3°C | 307 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00021504; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Hilo?
Every month's normal high in Hilo falls between 65°F and 85°F.
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00021504.
How hot and how cold does it get in Hilo?
In a normal year in Hilo, 2 days a year reach 90°F, nights almost never fall to freezing and 273 days bring measurable precipitation.
- Days at 90°F or more
- 2a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- fewer than 1a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 273a normal year
The highest temperature in Hilo's official record (kept by the National Weather Service since 1949) is 94°F, on May 20, 1966; the lowest is 53°F, on February 21, 1962.
The wettest calendar year on that record is 1990, with 211.22 in.
Source: NOAA NCEI 1991-2020 annual normals, station USW00021504; records: ACIS (NOAA Regional Climate Centers), NWS threaded record ITOthr. Records use complete months only; a month missing more than three days is left out.
How humid and windy is Hilo, and how clear are its skies?
The summer (June-August) dew point averages 68°F. The muggiest month is July, with an average dew point of 69°F, above the 65°F at which most people call the air sticky; the driest air comes in January (62°F). February is the windiest month (7.1 mph on average), and January has the most clear or nearly clear hours (36%).
| Month | Dew point | Humidity | Afternoon humidity | Wind | Clear or few clouds | Overcast |
|---|---|---|---|---|---|---|
| January | 62°F | 74% | 63% | 6.9 mph | 36% | 30% |
| February | 63°F | 75% | 65% | 7.1 mph | 26% | 39% |
| March | 64°F | 78% | 67% | 6.8 mph | 20% | 42% |
| April | 65°F | 77% | 66% | 6.7 mph | 17% | 42% |
| May | 66°F | 76% | 64% | 6.4 mph | 21% | 30% |
| June | 68°F | 77% | 65% | 6.5 mph | 20% | 34% |
| July | 69°F | 79% | 68% | 6.3 mph | 19% | 38% |
| August | 69°F | 78% | 67% | 6.4 mph | 26% | 34% |
| September | 68°F | 77% | 67% | 6.2 mph | 26% | 32% |
| October | 68°F | 80% | 70% | 6.1 mph | 22% | 37% |
| November | 66°F | 80% | 71% | 6.3 mph | 22% | 39% |
| December | 63°F | 76% | 67% | 6.4 mph | 35% | 32% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00021504. Monthly averages of all hours; afternoon humidity at 3 p.m. local standard time; sky as the share of hours NOAA's observations rate clear or few clouds (a dash where NOAA publishes no sky value).
How sunny is Hilo?
Over a year 75% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Hilo, 5.3 kWh per square metre a day. January is the sunniest month (79%) and March the cloudiest (71%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 79% | 4.4 |
| February | 75% | 4.8 |
| March | 71% | 5.2 |
| April | 71% | 5.7 |
| May | 72% | 5.9 |
| June | 74% | 6.1 |
| July | 76% | 6.2 |
| August | 76% | 6.1 |
| September | 75% | 5.6 |
| October | 76% | 5.0 |
| November | 76% | 4.4 |
| December | 76% | 4.0 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Hilo need?
A normal year in Hilo brings 0 heating degree days, 100% fewer than the median U.S. place (5,373), and 3,283 cooling degree days, 3.6 times the median (908). No month reaches 300 heating degree days. For gardens and crops, NOAA counts 8,758 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 0 | 198 |
| February | 0 | 175 |
| March | 0 | 212 |
| April | 0 | 227 |
| May | 0 | 279 |
| June | 0 | 308 |
| July | 0 | 352 |
| August | 0 | 361 |
| September | 0 | 347 |
| October | 0 | 332 |
| November | 0 | 269 |
| December | 0 | 225 |
| Year (annual) | 0 | 3,283 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00021504. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Hilo been warmer than normal lately?
2023 averaged 75.0°F, 1.0°F above the 1991-2020 normal of 74.0°F. 2 of the 2 complete years since 2022 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2022 | 75.1°F | +1.1°F | 94.04 |
| 2023 | 75.0°F | +1.0°F | 102.49 |
Over 38 complete years from 1983 to 2025, the station's annual mean temperature rose at a fitted 3.5°F per century (+0.19°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USW00021504; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Hilo's climate compare?
Hilo is warmer than 5 of the other 17 places with their own NOAA record in Hawaii, and wetter than 16. Across the 7,247 U.S. stations with normals, its annual mean of 74.0°F is warmer than 98%.
In the Köppen classification computed from these normals, Hilo is Af: tropical rainforest. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Hilo share this climate record?
6 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Hawaiian Paradise Park, HI13,273 people · 11 mi SE
- Pepeekeo, HI1,505 people · 9 mi NW
- Papaikou, HI1,325 people · 6 mi NW
- Keaau, HI1,210 people · 7 mi S
- Wainaku, HI1,082 people · 3 mi NW
- Paukaa, HI528 people · 4 mi NW
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
What do Hilo's other NOAA stations record?
One more NOAA station keeps 1991-2020 normals in or near Hilo. This page uses Hilo International Airport 87; the other differs by site and elevation:
| Station | From this station | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Hilo (5 mi S) USW00021515 | 5 mi S | 622 ft | 70.6°F | 61°F | 79°F | 151.2 | – | – |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Hilo's climate
What is the coldest month in Hilo?
February, with a normal high of 78°F and a normal low of 64°F. The warmest is August (83°F by day, 70°F at night).
What is the rainiest month in Hilo?
November, with 14.39 in of precipitation in a normal year; the driest is May with 6.99 in.
What plant hardiness zone is Hilo in?
The USDA's 2023 map puts Hilo in zone 11a in ZIP code 96720. By the same method at Hilo's NOAA station, the coldest night of a typical year reaches 58°F (30 years, 1991-2020): zone 12b.
Nearby and next
- Hilo in OctoberThis month day by day, its records and recent years
- Hawaii climateThe statewide normals and every place in the state
- Glenwood #2 55.4, HI15 miles from this station, 67.0°F a year
- Kihalani 132.5, HI21 miles from this station, 71.4°F a year
- Hawaii Vol National Park Headquarters 54, HI24 miles from this station, 61.7°F a year
- Paauilo, HI30 miles from this station, 70.5°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made