Weather on September 18
Fort Collins, CO
55 Years of Data
About This Date
September 18th in Fort Collins, CO typically brings pleasant fall weather, with average highs around 77°F and lows near 47°F — a 30°F daily swing. Over 56 years of records, the warmest September 18th was in 2000 (76°F average), while the coldest was 1971 (37°F) — a 39°F range across recorded history. Precipitation has occurred on 16% of recorded September 18th dates, with snow falling 2% of the time (heaviest snowfall: 2"). The last decade has been 3.6°F warmer on this date compared to 20-30 years ago.
The last decade has been 3.6°F warmer on this date compared to 20-30 years ago.
Planning for September 18th in Fort Collins, CO? Great weather for outdoor activities.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2026 | 87° | 57° | 72° | — | — |
| 2025 | 74° | 45° | 59° | — | — |
| 2024 | 81° | 46° | 63° | — | — |
| 2023 | 85° | 49° | 67° | — | — |
| 2022 | 81° | 50° | 65° | — | — |
| 2021 | 89° | 42° | 66° | — | — |
| 2020 | 76° | 46° | 61° | — | — |
| 2019 | 77° | 57° | 67° | — | — |
| 2018 | 87° | 53° | 70° | — | — |
| 2017 | 81° | 42° | 61° | — | — |
| 2016 | 89° | 48° | 69° | — | — |
| 2015 | 73° | 50° | 62° | — | — |
| 2014 | 88° | 48° | 68° | — | — |
| 2013 | 84° | 57° | 71° | — | — |
| 2012 | 78° | 42° | 60° | — | — |
| 2011 | 73° | 41° | 57° | — | — |
| 2010 | 67° | 47° | 57° | — | — |
| 2009 | 77° | 44° | 61° | — | — |
| 2008 | 78° | 46° | 62° | — | — |
| 2007 | 76° | 52° | 64° | — | — |
| 2006 | 65° | 44° | 54° | — | — |
| 2005 | 76° | 43° | 59° | — | — |
| 2004 | 89° | 46° | 68° | — | — |
| 2003 | 58° | 36° | 47° | 0.01" | — |
| 2002 | 70° | 53° | 61° | — | — |
| 2001 | 71° | 49° | 60° | 0.03" | — |
| 2000warmest | 87° | 65° | 76° | — | — |
| 1999 | 82° | 42° | 62° | — | — |
| 1998 | 87° | 50° | 69° | — | — |
| 1997 | 75° | 57° | 66° | 0.09" | — |
| 1996 | 60° | 42° | 51° | 0.2" | — |
| 1995 | 76° | 55° | 65° | 0.28" | — |
| 1994 | 82° | 44° | 63° | — | — |
| 1993 | 53° | 45° | 49° | 0.83" | — |
| 1992 | 71° | 41° | 56° | — | — |
| 1991 | 59° | 40° | 49° | — | — |
| 1990 | 75° | 46° | 61° | 0.2" | — |
| 1989 | 85° | 51° | 68° | — | — |
| 1988 | 80° | 47° | 63° | — | — |
| 1987 | 67° | 35° | 51° | — | — |
| 1986 | 70° | 52° | 61° | — | — |
| 1985 | 81° | 47° | 64° | — | — |
| 1984 | 86° | 46° | 66° | — | — |
| 1983 | 77° | 46° | 62° | — | — |
| 1982 | 74° | 50° | 62° | — | — |
| 1981 | 83° | 40° | 61° | — | — |
| 1980 | 86° | 45° | 65° | — | — |
| 1979 | 74° | 49° | 61° | — | — |
| 1978 | 73° | 47° | 60° | 0.02" | — |
| 1977 | 70° | 42° | 56° | — | — |
| 1976 | 80° | 48° | 64° | — | — |
| 1975 | 74° | 47° | 60° | — | — |
| 1974 | 82° | 43° | 62° | — | — |
| 1973 | 78° | 39° | 59° | — | — |
| 1972 | 83° | 49° | 66° | — | — |
| 1971coldest | 44° | 31° | 37° | 0.31" | 2" |
Fort Collins, CO Temperature Range by Month
Average monthly highs and lows. The shaded band shows the typical daily temperature range.
Fort Collins, CO Monthly Precipitation
Average rainfall and snowfall per month, in inches.
Fort Collins, CO Daily Temperature Calendar
Average daily high temperature for every day of the year. Each cell is the climatological mean for that calendar day across 55 years of NOAA data.
Best Time to Visit Fort Collins, CO
Most pleasant months in Fort Collins, CO: May, June, September.
What to expect on September 18th
This page shows what actually happened each year. For the odds — typical high and low, and how often it stays dry — see the climatological outlook for this date.
September 18th outlook →