Weather on September 18 at North Cascades
North Cascades National Park
Based on 54 years of data from Seattle, WA
Elevation Note: North Cascades sits at 4,200 ft. Expect temperatures 15°F cooler than the data shown below, which comes from Seattle, WA at a lower elevation.
Planning Your Visit
September 18th in North Cascades National Park (via Seattle, WA) typically brings mild fall weather, with average highs around 69°F and lows near 53°F. Over 54 years of records, the warmest September 18th was in 1991 (69°F average), while the coldest was 1988 (52°F) — a 17°F range across recorded history. Rain or other precipitation has occurred on about 41% of September 18th dates historically, with the wettest September 18th recording 0.82" of rain. The last decade has been 1.6°F warmer on this date compared to 20-30 years ago.
The last decade has been 1.6°F warmer on this date compared to 20-30 years ago.
Planning for September 18th in North Cascades? Great weather for outdoor activities. Consider bringing rain gear or an umbrella.
Year by Year History
| Year | High | Low | Precip | Snow |
|---|---|---|---|---|
| 2025 | 72°F | 56°F | 0" | -- |
| 2024 | 71°F | 59°F | 0" | -- |
| 2023 | 65°F | 54°F | 0.22" | -- |
| 2022 | 72°F | 56°F | 0" | -- |
| 2021 | 65°F | 53°F | 0.34" | -- |
| 2020 | 68°F | 61°F | 0.22" | -- |
| 2019 | 68°F | 55°F | 0.06" | -- |
| 2018 | 66°F | 49°F | 0" | -- |
| 2017 | 63°F | 51°F | 0.17" | -- |
| 2016 | 69°F | 53°F | 0" | -- |
| 2015 | 70°F | 56°F | 0.01" | -- |
| 2014 | 72°F | 62°F | 0" | -- |
| 2013 | 71°F | 57°F | 0" | -- |
| 2012 | 80°F | 54°F | 0" | -- |
| 2011 | 68°F | 53°F | 0.16" | -- |
| 2010 | 75°F | 61°F | 0.82" | -- |
| 2009 | 83°F | 53°F | 0" | -- |
| 2008 | 61°F | 55°F | 0" | -- |
| 2007 | 63°F | 48°F | 0" | -- |
| 2006 | 69°F | 56°F | 0.32" | -- |
| 2005 | 69°F | 50°F | 0" | -- |
| 2004 | 57°F | 48°F | 0.08" | -- |
| 2003 | 68°F | 54°F | 0.01" | -- |
| 2002 | 72°F | 47°F | 0" | -- |
| 2001 | 64°F | 55°F | 0.11" | -- |
| 2000 | 72°F | 62°F | 0.01" | -- |
| 1999 | 75°F | 51°F | 0" | -- |
| 1997 | 66°F | 51°F | 0.16" | 0" |
| 1996 | 61°F | 48°F | 0.11" | 0" |
| 1995 | 74°F | 57°F | 0" | 0" |
| 1994 | 74°F | 56°F | 0" | 0" |
| 1993 | 64°F | 50°F | 0" | 0" |
| 1992 | 69°F | 46°F | 0.02" | 0" |
| 1991 | 83°F | 56°F | 0" | 0" |
| 1990 | 73°F | 54°F | 0" | 0" |
| 1989 | 67°F | 47°F | 0" | 0" |
| 1988 | 59°F | 45°F | 0.14" | 0" |
| 1987 | 70°F | 50°F | 0" | 0" |
| 1986 | 66°F | 54°F | 0.13" | 0" |
| 1985 | 63°F | 49°F | 0" | 0" |
| 1984 | 73°F | 58°F | 0" | 0" |
| 1983 | 61°F | 47°F | 0.8" | 0" |
| 1982 | 76°F | 53°F | 0" | 0" |
| 1981 | 75°F | 58°F | 0.27" | 0" |
| 1980 | 67°F | 58°F | 0" | 0" |
| 1979 | 77°F | 55°F | 0" | 0" |
| 1978 | 63°F | 46°F | 0" | 0" |
| 1977 | 64°F | 54°F | 0.18" | 0" |
| 1976 | 68°F | 58°F | 0" | 0" |
| 1975 | 71°F | 49°F | 0" | 0" |
| 1974 | 74°F | 55°F | 0" | 0" |
| 1973 | 65°F | 55°F | 0.03" | 0" |
| 1972 | 64°F | 51°F | 0" | 0" |
| 1971 | 77°F | 53°F | 0" | 0" |