Weather on September 21 at Channel Islands
Channel Islands National Park
Based on 55 years of data from Ventura, CA
Planning Your Visit
September 21st in Channel Islands National Park (via Ventura, CA) typically brings warm fall weather, with average highs around 84°F and lows near 53°F — a 31°F daily swing. Over 55 years of records, the warmest September 21st was in 2015 (80°F average), while the coldest was 1988 (57°F) — a 23°F range across recorded history. Rain or other precipitation has occurred on about 2% of September 21st dates historically. The last decade has been 2.7°F cooler on this date compared to 20-30 years ago.
The last decade has been 2.7°F cooler on this date compared to 20-30 years ago.
Planning for September 21st in Channel Islands? Stay hydrated and seek shade during peak afternoon hours.
Year by Year History
| Year | High | Low | Precip | Snow |
|---|---|---|---|---|
| 2025 | 88°F | 54°F | 0" | -- |
| 2024 | 77°F | 46°F | 0" | -- |
| 2023 | 70°F | 56°F | 0.05" | -- |
| 2022 | 81°F | 47°F | 0" | -- |
| 2021 | 87°F | 49°F | 0" | -- |
| 2020 | 92°F | 44°F | 0" | -- |
| 2019 | 83°F | 46°F | 0" | -- |
| 2018 | 88°F | 56°F | 0" | -- |
| 2017 | 74°F | 52°F | 0" | -- |
| 2016 | 93°F | 58°F | 0" | -- |
| 2015 | 102°F | 57°F | 0" | -- |
| 2014 | 83°F | 53°F | 0" | -- |
| 2013 | 78°F | 53°F | 0" | -- |
| 2012 | 95°F | 59°F | -- | -- |
| 2011 | 81°F | 55°F | -- | -- |
| 2010 | 68°F | 50°F | -- | -- |
| 2009 | 88°F | 52°F | -- | -- |
| 2008 | 73°F | 50°F | -- | -- |
| 2007 | 73°F | 45°F | -- | -- |
| 2006 | 77°F | 50°F | -- | -- |
| 2005 | 82°F | 52°F | -- | -- |
| 2004 | 84°F | 54°F | -- | -- |
| 2003 | 99°F | 54°F | -- | -- |
| 2002 | 91°F | 54°F | -- | -- |
| 2001 | 86°F | 50°F | -- | -- |
| 2000 | 68°F | 61°F | -- | -- |
| 1999 | 85°F | 52°F | 0" | 0" |
| 1998 | 75°F | 62°F | 0" | 0" |
| 1997 | 95°F | 52°F | 0" | 0" |
| 1996 | 88°F | 55°F | 0" | 0" |
| 1995 | 87°F | 53°F | 0" | 0" |
| 1994 | 84°F | 49°F | 0" | 0" |
| 1993 | 73°F | 51°F | 0" | 0" |
| 1992 | 100°F | 49°F | 0" | 0" |
| 1991 | 92°F | 52°F | 0" | 0" |
| 1990 | 76°F | 59°F | 0" | 0" |
| 1989 | 100°F | 53°F | 0" | 0" |
| 1988 | 68°F | 47°F | 0" | 0" |
| 1987 | 92°F | 55°F | 0" | 0" |
| 1986 | 71°F | 48°F | 0" | 0" |
| 1985 | 90°F | 44°F | 0" | 0" |
| 1984 | 81°F | 69°F | 0" | 0" |
| 1983 | 85°F | 71°F | 0" | 0" |
| 1982 | 89°F | 49°F | 0" | 0" |
| 1981 | 87°F | 49°F | 0" | 0" |
| 1980 | 75°F | 42°F | 0" | 0" |
| 1979 | 91°F | 49°F | 0" | 0" |
| 1978 | 90°F | 42°F | 0" | 0" |
| 1977 | 84°F | 49°F | 0" | 0" |
| 1976 | 79°F | 57°F | 0" | 0" |
| 1975 | 96°F | 61°F | 0" | 0" |
| 1974 | 83°F | 53°F | 0" | 0" |
| 1973 | 73°F | 54°F | 0" | 0" |
| 1972 | 98°F | 53°F | 0" | 0" |
| 1971 | 77°F | 56°F | 0" | 0" |