Weather on December 18
Flagstaff, AZ
55 Years of Data
About This Date
December 18th in Flagstaff, AZ typically brings chilly winter weather, with average highs around 44°F and lows near 18°F — a 26°F daily swing. Over 55 years of records, the warmest December 18th was in 2025 (46°F average), while the coldest was 1992 (19°F) — a 27°F range across recorded history. Precipitation has occurred on 24% of recorded December 18th dates, with snow falling 22% of the time (heaviest snowfall: 5.3"). The last decade has been 1.1°F warmer on this date compared to 20-30 years ago.
The last decade has been 1.1°F warmer on this date compared to 20-30 years ago.
Planning for December 18th in Flagstaff, AZ? Bring layers as temperatures can vary throughout the day. Check road conditions if traveling, as snow is possible.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025warmest | 62° | 30° | 46° | — | — |
| 2024 | 54° | 24° | 39° | — | — |
| 2023 | 57° | 21° | 39° | — | — |
| 2022 | 36° | 14° | 25° | — | — |
| 2021 | 35° | 16° | 26° | — | — |
| 2020 | 40° | 14° | 27° | — | — |
| 2019 | 38° | 15° | 27° | — | — |
| 2018 | 49° | 20° | 35° | — | — |
| 2017 | 50° | 13° | 32° | — | — |
| 2016 | 30° | 9° | 20° | — | — |
| 2015 | 51° | 10° | 31° | — | — |
| 2014 | 36° | 17° | 27° | 0.2" | 2" |
| 2013 | 52° | 24° | 38° | — | — |
| 2012 | 34° | 30° | 32° | 0.3" | 1.6" |
| 2011 | 38° | 27° | 32° | 0.16" | 1.5" |
| 2010 | 37° | 32° | 35° | 0.07" | 0.5" |
| 2009 | 44° | 12° | 28° | — | — |
| 2008 | 35° | 24° | 30° | 0.48" | 4.4" |
| 2007 | 39° | 12° | 26° | — | — |
| 2006 | 32° | 19° | 26° | 0.19" | 5.3" |
| 2005 | 40° | 17° | 28° | — | — |
| 2004 | 46° | 30° | 38° | — | — |
| 2003 | 50° | 14° | 32° | — | — |
| 2002 | 29° | 20° | 24° | 0.29" | — |
| 2001 | 50° | 10° | 30° | — | — |
| 2000 | 40° | 23° | 31° | — | — |
| 1999 | 53° | 13° | 33° | — | — |
| 1998 | 48° | 24° | 36° | — | — |
| 1997 | 43° | 20° | 31° | — | — |
| 1996 | 33° | 11° | 22° | — | — |
| 1995 | 41° | 16° | 28° | — | — |
| 1994 | 54° | 15° | 34° | — | — |
| 1993 | 45° | 12° | 28° | — | — |
| 1992coldest | 28° | 11° | 19° | 0.16" | 3.7" |
| 1991 | 36° | 32° | 34° | 0.32" | 0.6" |
| 1990 | 42° | 13° | 27° | — | — |
| 1989 | 42° | 10° | 26° | — | — |
| 1988 | 51° | 22° | 36° | 0.05" | 0.5" |
| 1987 | 38° | 21° | 29° | 0.27" | 3.2" |
| 1986 | 43° | 21° | 32° | — | — |
| 1985 | 49° | 21° | 35° | — | — |
| 1984 | 38° | 20° | 29° | — | — |
| 1983 | 48° | 21° | 35° | — | — |
| 1982 | 57° | 19° | 38° | — | — |
| 1981 | 58° | 19° | 38° | — | — |
| 1980 | 56° | 29° | 42° | — | — |
| 1979 | 58° | 13° | 35° | — | — |
| 1978 | 40° | 31° | 35° | 2.65" | 0.7" |
| 1977 | 40° | 28° | 34° | 0.18" | 1.2" |
| 1976 | 51° | 15° | 33° | — | — |
| 1975 | 38° | 6° | 22° | — | — |
| 1974 | 48° | 10° | 29° | — | — |
| 1973 | 45° | 22° | 33° | — | — |
| 1972 | 51° | 16° | 33° | — | — |
| 1971 | 35° | 7° | 21° | — | — |
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.