Weather on September 12
Flagstaff, AZ
55 Years of Data
About This Date
September 12th in Flagstaff, AZ typically brings pleasant fall weather, with average highs around 75°F and lows near 42°F — a 33°F daily swing. Over 55 years of records, the warmest September 12th was in 1990 (70°F average), while the coldest was 1985 (47°F) — a 23°F range across recorded history. Rain or other precipitation has occurred on about 24% of September 12th dates historically, with the wettest September 12th recording 0.63" of rain. The last decade has been 1.4°F warmer on this date compared to 20-30 years ago.
The last decade has been 1.4°F warmer on this date compared to 20-30 years ago.
Planning for September 12th in Flagstaff, AZ? Great weather for outdoor activities.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 74° | 45° | 59° | — | — |
| 2024 | 77° | 43° | 60° | — | — |
| 2023 | 68° | 55° | 62° | 0.05" | — |
| 2022 | 76° | 53° | 64° | 0.02" | — |
| 2021 | 81° | 47° | 64° | — | — |
| 2020 | 74° | 32° | 53° | — | — |
| 2019 | 74° | 36° | 55° | — | — |
| 2018 | 77° | 44° | 61° | — | — |
| 2017 | 82° | 50° | 66° | — | — |
| 2016 | 73° | 44° | 59° | — | — |
| 2015 | 79° | 45° | 62° | — | — |
| 2014 | 80° | 41° | 61° | — | — |
| 2013 | 73° | 40° | 56° | — | — |
| 2012 | 69° | 49° | 59° | — | — |
| 2011 | 67° | 47° | 57° | 0.28" | — |
| 2010 | 76° | 38° | 57° | — | — |
| 2009 | 78° | 42° | 60° | — | — |
| 2008 | 75° | 39° | 57° | — | — |
| 2007 | 79° | 47° | 63° | — | — |
| 2006 | 74° | 40° | 57° | — | — |
| 2005 | 68° | 43° | 55° | — | — |
| 2004 | 78° | 44° | 61° | 0.03" | — |
| 2003 | 75° | 35° | 55° | — | — |
| 2002 | 71° | 43° | 57° | — | — |
| 2001 | 83° | 43° | 63° | — | — |
| 2000 | 83° | 45° | 64° | — | — |
| 1999 | 73° | 41° | 57° | — | — |
| 1998 | 72° | 49° | 60° | 0.04" | — |
| 1997 | 73° | 49° | 61° | 0.16" | — |
| 1996 | 70° | 43° | 56° | 0.47" | — |
| 1995 | 79° | 39° | 59° | — | — |
| 1994 | 71° | 45° | 58° | 0.04" | — |
| 1993 | 73° | 46° | 60° | 0.63" | — |
| 1992 | 78° | 43° | 60° | — | — |
| 1991 | 72° | 35° | 53° | — | — |
| 1990warmest | 88° | 52° | 70° | — | — |
| 1989 | 73° | 41° | 57° | — | — |
| 1988 | 68° | 46° | 57° | — | — |
| 1987 | 75° | 37° | 56° | — | — |
| 1986 | 70° | 36° | 53° | — | — |
| 1985coldest | 70° | 25° | 47° | — | — |
| 1984 | 77° | 39° | 58° | — | — |
| 1983 | 83° | 45° | 64° | 0.11" | — |
| 1982 | 62° | 41° | 52° | — | — |
| 1981 | 76° | 45° | 60° | 0.05" | — |
| 1980 | 73° | 42° | 58° | — | — |
| 1979 | 82° | 42° | 62° | — | — |
| 1978 | 69° | 38° | 53° | — | — |
| 1977 | 71° | 50° | 61° | 0.05" | — |
| 1976 | 73° | 40° | 56° | — | — |
| 1975 | 75° | 48° | 62° | 0.14" | — |
| 1974 | 77° | 38° | 57° | — | — |
| 1973 | 80° | 36° | 58° | — | — |
| 1972 | 74° | 35° | 54° | — | — |
| 1971 | 80° | 38° | 59° | — | — |
Flagstaff, AZ Temperature Range by Month
Average monthly highs and lows. The shaded band shows the typical daily temperature range.
Flagstaff, AZ Monthly Precipitation
Average rainfall and snowfall per month, in inches.
Flagstaff, AZ 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 Flagstaff, AZ
Most pleasant months in Flagstaff, AZ: May, June, July, August, September.