April is one of the cooler months of the year in Hilo, with average highs near 22.7°C and lows around 18.8°C (mean 20.8°C). It is a relatively wet time of year, averaging 235 mm of rainfall and 81% relative humidity across the period.
April is one of the cooler months of the year in Hilo. Across 45 years of records, the warmest April in Hilo was 1996 — when the month averaged 22.2°C — while the coldest was 1983 at 19.5°C. Typical April days reach 22.7°C with nights near 18.8°C. The long-term trend is warming, about 0.2°C per decade.
April is a relatively wet time of year in Hilo, averaging 235 mm of rainfall. The wettest April on record was 1983 with 2852 mm, while the driest was 1994 at 2 mm.
Relative humidity in Hilo during April averages 81%. The most humid April was 2018 at 87%, and the least humid was 1993 at 73%.
April receives about 5.6 kWh/m²/day of solar energy in Hilo. The sunniest April was 2000 at 6.1 kWh/m²/day, and the cloudiest was 2018 at 4.8.
Average wind speed in Hilo during April is 4.3 m/s. The windiest April was 1998 at 5.6 m/s, while the calmest was 2020 at 3.4 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 20.3°C | 21.0°C | 20.5°C | 21.0°C | 21.2°C | +0.9°C |
| Avg High | 22.2°C | 23.2°C | 22.2°C | 22.8°C | 23.1°C | +0.9°C |
| Avg Low | 18.4°C | 18.8°C | 18.7°C | 19.2°C | 19.2°C | +0.8°C |
| Avg Rain | 491 mm | 62 mm | 277 mm | 201 mm | 123 mm | -368 mm |
April temperatures in Hilo have risen by about 1°C between 1981–1985 and 2021–2025.
April has ranged from a record low of 15.8°C (1982) to a record high of 27.5°C (2018).
Rainfall in April is a relatively wet time of year, averaging 235 mm, with a wettest year of 2852 mm.
A quieter season to visit Hilo
If your dates are flexible, the more temperate months of June and May tend to be the most comfortable for visiting Hilo. That said, April — with days averaging 22.7°C and nights around 18.8°C (mean 20.8°C) and higher rainfall (235 mm) — can still be rewarding for travellers who don't mind the cooler conditions, and often means fewer crowds.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 23.8°C | 21.7°C | 19.7°C | 25.1°C | 19.0°C | 91 mm | 81% | 3.9 m/s | 5.9 |
| 2024 | 22.7°C | 20.9°C | 19.0°C | 25.8°C | 18.2°C | 142 mm | 85% | 4.1 m/s | 5.8 |
| 2023 | 22.9°C | 21.1°C | 19.2°C | 24.9°C | 18.1°C | 207 mm | 84% | 3.9 m/s | 5.6 |
| 2022 | 22.6°C | 21.0°C | 19.4°C | 23.4°C | 18.6°C | 154 mm | 84% | 4.5 m/s | 5.5 |
| 2021 | 22.8°C | 20.7°C | 18.5°C | 25.1°C | 17.3°C | 73 mm | 78% | 3.8 m/s | 5.8 |
| 2020 | 23.6°C | 21.5°C | 19.3°C | 25.8°C | 18.1°C | 72 mm | 82% | 3.4 m/s | 6 |
| 2019 | 23.2°C | 21.3°C | 19.4°C | 25.4°C | 18.3°C | 128 mm | 84% | 4 m/s | 6 |
| 2018 | 23.6°C | 21.9°C | 20.3°C | 27.5°C | 19.2°C | 442 mm | 87% | 3.8 m/s | 4.8 |
| 2017 | 23.5°C | 21.5°C | 19.5°C | 24.7°C | 18.5°C | 378 mm | 83% | 3.6 m/s | 5.7 |
| 2016 | 23.2°C | 21.4°C | 19.6°C | 24.3°C | 18.6°C | 191 mm | 83% | 4.3 m/s | 5.8 |
| 2015 | 22.7°C | 21.0°C | 19.3°C | 24.5°C | 18.5°C | 158 mm | 84% | 4.5 m/s | 5.7 |
| 2014 | 22.6°C | 21.0°C | 19.3°C | 23.8°C | 17.9°C | 115 mm | 83% | 4.7 m/s | 5.7 |
| 2013 | 23.5°C | 21.3°C | 19.1°C | 25.7°C | 16.9°C | 29 mm | 80% | 3.7 m/s | 6 |
| 2012 | 21.7°C | 20.0°C | 18.2°C | 23.2°C | 17.5°C | 62 mm | 82% | 4.5 m/s | 5.7 |
| 2011 | 22.6°C | 20.7°C | 18.8°C | 23.8°C | 18.0°C | 184 mm | 83% | 3.7 m/s | 5.5 |
| 2010 | 21.6°C | 19.9°C | 18.3°C | 23.1°C | 16.0°C | 326 mm | 84% | 4.7 m/s | 5.9 |
| 2009 | 21.7°C | 20.0°C | 18.3°C | 24.2°C | 17.4°C | 893 mm | 85% | 4 m/s | 5.1 |
| 2008 | 22.4°C | 20.6°C | 18.7°C | 23.9°C | 16.7°C | 114 mm | 83% | 4.2 m/s | 5.5 |
| 2007 | 22.4°C | 20.5°C | 18.6°C | 24.0°C | 17.0°C | 71 mm | 80% | 4.4 m/s | 6 |
| 2006 | 21.5°C | 20.0°C | 18.5°C | 23.9°C | 17.8°C | 334 mm | 83% | 4.9 m/s | 5.7 |
| 2005 | 22.3°C | 20.7°C | 19.0°C | 25.2°C | 17.9°C | 290 mm | 82% | 4.6 m/s | 6 |
| 2004 | 22.7°C | 21.0°C | 19.2°C | 24.8°C | 18.5°C | 477 mm | 85% | 4.2 m/s | 5.5 |
| 2003 | 22.0°C | 20.4°C | 18.7°C | 23.3°C | 18.0°C | 216 mm | 84% | 4.5 m/s | 5.3 |
| 2002 | 23.4°C | 21.3°C | 19.3°C | 25.8°C | 18.3°C | 251 mm | 84% | 3.8 m/s | 5.6 |
| 2001 | 22.0°C | 20.2°C | 18.5°C | 23.0°C | 17.6°C | 87 mm | 80% | 5.2 m/s | 5.6 |
| 2000 | 21.9°C | 19.9°C | 17.9°C | 24.6°C | 16.8°C | 35 mm | 77% | 4.9 m/s | 6.1 |
| 1999 | 21.8°C | 19.9°C | 18.0°C | 23.4°C | 17.0°C | 75 mm | 79% | 4.9 m/s | 5.8 |
| 1998 | 22.2°C | 20.3°C | 18.3°C | 23.7°C | 16.5°C | 5 mm | 75% | 5.6 m/s | 5.8 |
| 1997 | 24.2°C | 21.8°C | 19.3°C | 26.0°C | 18.2°C | 17 mm | 74% | 4.3 m/s | 5.7 |
| 1996 🔥 | 24.7°C | 22.2°C | 19.7°C | 26.7°C | 18.6°C | 9 mm | 77% | 4.3 m/s | 5.8 |
| 1995 | 23.8°C | 21.4°C | 19.0°C | 26.4°C | 17.9°C | 8 mm | 76% | 4.4 m/s | 5.7 |
| 1994 | 23.0°C | 20.9°C | 18.8°C | 24.5°C | 17.0°C | 2 mm | 77% | 5.2 m/s | 5.8 |
| 1993 | 23.6°C | 21.3°C | 19.1°C | 25.7°C | 18.3°C | 3 mm | 73% | 4.9 m/s | 5.8 |
| 1992 | 23.9°C | 21.4°C | 18.9°C | 26.6°C | 17.8°C | 22 mm | 76% | 3.6 m/s | 5.9 |
| 1991 | 22.2°C | 20.3°C | 18.4°C | 23.3°C | 16.7°C | 12 mm | 81% | 4.5 m/s | 5.4 |
| 1990 | 22.9°C | 20.9°C | 18.8°C | 24.5°C | 17.1°C | 466 mm | 82% | 3.7 m/s | 5.2 |
| 1989 | 23.1°C | 21.1°C | 19.2°C | 25.0°C | 17.6°C | 60 mm | 80% | 4.3 m/s | 5 |
| 1988 | 22.2°C | 20.3°C | 18.5°C | 23.3°C | 17.7°C | 182 mm | 81% | 4.5 m/s | 5.5 |
| 1987 | 21.9°C | 20.0°C | 18.1°C | 25.8°C | 16.7°C | 170 mm | 81% | 4.2 m/s | 5.9 |
| 1986 | 22.5°C | 20.9°C | 19.3°C | 24.1°C | 18.2°C | 294 mm | 84% | 4.9 m/s | 5.2 |
| 1985 | 21.5°C | 19.6°C | 17.7°C | 23.4°C | 15.9°C | 635 mm | 83% | 4 m/s | 5.3 |
| 1984 | 21.7°C | 20.1°C | 18.4°C | 23.3°C | 17.0°C | 130 mm | 83% | 4.9 m/s | 5.5 |
| 1983 ❄️ 🌧️ | 21.2°C | 19.5°C | 17.9°C | 23.6°C | 16.3°C | 2852 mm | 83% | 4.4 m/s | — |
| 1982 | 22.3°C | 20.2°C | 18.2°C | 26.0°C | 15.8°C | 57 mm | 82% | 4.2 m/s | — |
| 1981 | 23.5°C | 21.1°C | 18.7°C | 24.7°C | 17.5°C | 36 mm | 79% | 3.8 m/s | — |
Actual recorded April data for each year, 1981–2025 — sourced from NASA POWER.
The average high in April is around 22.7°C with lows near 18.8°C (mean 20.8°C), based on 45 years of NASA POWER data.
April averages 235 mm of rainfall in Hilo, a relatively wet time of year. The wettest on record was 2852 mm in 1983.
The hottest April reached 27.5°C in 2018. The coldest dipped to 15.8°C in 1982.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average April temperatures have risen by about 1°C. Daytime highs moved from 22°C to 23°C and overnight lows from 18.2°C to 19.2°C over the same span.
April is one of the cooler months of the year in Hilo and a relatively wet time of year, so plan for around 22.7°C daytime highs and 18.8°C at night.
Not quite — April is the 4th coolest month in Hilo, averaging 20.8°C.
For April in Hilo, pack light layers you can adjust through the day, with typical highs of 22.7°C and lows of 18.8°C. Bring an umbrella or light rain jacket too.
Relative humidity in April averages 81% — quite humid.
Average wind speed in April is 4.3 m/s. The windiest April on record averaged 5.6 m/s (1998).
The wettest April on record was 1983 with 2852 mm. On average, April sees 235 mm.
All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.
Explore how the weather in Hilo behaves each April, based on 45 years of NASA POWER climate data from 1981 to 2025. This page breaks down average temperatures, rainfall, humidity, wind and solar radiation for April specifically, along with year-by-year records and how the month has changed over the decades.
