Weather on September 21 at Hawaii Volcanoes
Hawaii Volcanoes National Park
Based on 55 years of data from Hilo, HI
Elevation Note: Hawaii Volcanoes sits at 4,000 ft. Expect temperatures 14°F cooler than the data shown below, which comes from Hilo, HI at a lower elevation.
Planning Your Visit
September 21st in Hawaii Volcanoes National Park (via Hilo, HI) typically brings warm fall weather, with average highs around 84°F and lows near 69°F. Over 55 years of records, the warmest September 21st was in 2014 (81°F average), while the coldest was 1999 (72°F) — a 9°F range across recorded history. Rain or other precipitation has occurred on about 75% of September 21st dates historically, with the wettest September 21st recording 11.71" of rain. The last decade has been 1.5°F warmer on this date compared to 20-30 years ago.
The last decade has been 1.5°F warmer on this date compared to 20-30 years ago.
Planning for September 21st in Hawaii Volcanoes? Stay hydrated and seek shade during peak afternoon hours. Consider bringing rain gear or an umbrella.
Year by Year History
| Year | High | Low | Precip | Snow |
|---|---|---|---|---|
| 2025 | 85°F | 69°F | 0.08" | -- |
| 2024 | 84°F | 69°F | 0.3" | -- |
| 2023 | 84°F | 69°F | 0.25" | -- |
| 2022 | 85°F | 69°F | 0.18" | -- |
| 2021 | 80°F | 71°F | 1.6" | -- |
| 2020 | 87°F | 69°F | 0.03" | -- |
| 2019 | 88°F | 74°F | 1.27" | -- |
| 2018 | 87°F | 72°F | 0" | -- |
| 2017 | 84°F | 68°F | 0.36" | -- |
| 2016 | 84°F | 70°F | 0.69" | -- |
| 2015 | 88°F | 73°F | 1.65" | -- |
| 2014 | 89°F | 74°F | 0.13" | -- |
| 2013 | 84°F | 69°F | 0.1" | 0" |
| 2012 | 84°F | 67°F | 0.18" | -- |
| 2011 | 83°F | 70°F | 0.84" | -- |
| 2010 | 83°F | 68°F | 0.23" | -- |
| 2009 | 84°F | 66°F | 0.1" | -- |
| 2008 | 83°F | 66°F | 0.28" | -- |
| 2007 | 82°F | 70°F | 0.53" | -- |
| 2006 | 83°F | 67°F | 0.51" | -- |
| 2005 | 84°F | 70°F | 0.13" | -- |
| 2004 | 87°F | 68°F | 0.03" | -- |
| 2003 | 84°F | 71°F | 0.08" | -- |
| 2002 | 84°F | 66°F | 0" | -- |
| 2001 | 83°F | 67°F | 0.81" | -- |
| 2000 | 82°F | 68°F | 0.58" | -- |
| 1999 | 79°F | 66°F | 2.54" | -- |
| 1998 | 82°F | 70°F | 2.82" | -- |
| 1997 | 86°F | 68°F | 0.03" | 0" |
| 1996 | 85°F | 69°F | 0" | 0" |
| 1995 | 86°F | 68°F | 0" | 0" |
| 1994 | 84°F | 69°F | 0.05" | 0" |
| 1993 | 85°F | 70°F | 0" | 0" |
| 1992 | 84°F | 68°F | 0.1" | 0" |
| 1991 | 84°F | 68°F | 0" | 0" |
| 1990 | 88°F | 71°F | 0" | 0" |
| 1989 | 81°F | 66°F | 0.15" | 0" |
| 1988 | 82°F | 68°F | 0.41" | 0" |
| 1987 | 84°F | 66°F | 0" | 0" |
| 1986 | 86°F | 74°F | 0.05" | 0" |
| 1985 | 81°F | 68°F | 0.51" | 0" |
| 1984 | 81°F | 70°F | 1.22" | 0" |
| 1983 | 81°F | 70°F | 2.16" | 0" |
| 1982 | 83°F | 69°F | 0" | 0" |
| 1981 | 87°F | 72°F | 0" | 0" |
| 1980 | 80°F | 71°F | 11.71" | 0" |
| 1979 | 86°F | 66°F | 0" | 0" |
| 1978 | 84°F | 67°F | 0.36" | 0" |
| 1977 | 87°F | 67°F | 0" | 0" |
| 1976 | 85°F | 66°F | 0.18" | 0" |
| 1975 | 84°F | 67°F | 0" | 0" |
| 1974 | 87°F | 67°F | 0" | 0" |
| 1973 | 86°F | 70°F | 0.38" | 0" |
| 1972 | 81°F | 68°F | 0.53" | 0" |
| 1971 | 82°F | 70°F | 3.43" | 0" |