Weather on December 31
Hillsboro, OR
55 Years of Data
Avg High
44°F
Avg Low
32°F
Warmest
1980
54°F avg
Coldest
1978
18°F avg
About This Date
December 31st in Hillsboro, OR typically brings chilly winter weather, with average highs around 44°F and lows near 32°F. Over 55 years of records, the warmest December 31st was in 1980 (54°F average), while the coldest was 1978 (18°F) — a 36°F range across recorded history. Precipitation has occurred on 55% of recorded December 31st dates, with snow falling 2% of the time. The last decade has been 3.4°F cooler on this date compared to 20-30 years ago.
The last decade has been 3.4°F cooler on this date compared to 20-30 years ago.
Planning for December 31st in Hillsboro, OR? Bring layers as temperatures can vary throughout the day. Consider bringing rain gear or an umbrella.
Warming Trend
0.3°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 47° | 26° | 36° | — | — |
| 2024 | 51° | 33° | 42° | 0.13" | — |
| 2023 | 44° | 40° | 42° | — | — |
| 2022 | 49° | 36° | 42° | 0.2" | — |
| 2021 | 39° | 24° | 32° | 0.1" | — |
| 2020 | 51° | 45° | 48° | 0.1" | — |
| 2019 | 50° | 39° | 45° | 0.51" | — |
| 2018 | 46° | 28° | 37° | — | — |
| 2017 | 50° | 25° | 38° | — | — |
| 2016 | 35° | 24° | 30° | 0.25" | — |
| 2015 | 38° | 31° | 35° | — | — |
| 2014 | 39° | 19° | 29° | — | — |
| 2013 | 48° | 35° | 42° | 0.05" | — |
| 2012 | 35° | 25° | 30° | 0.03" | — |
| 2011 | 39° | 27° | 33° | — | — |
| 2010 | 35° | 22° | 29° | — | — |
| 2009 | 48° | 31° | 40° | 2.03" | — |
| 2008 | 45° | 39° | 42° | 0.15" | — |
| 2007 | 40° | 28° | 34° | — | — |
| 2006 | 41° | 27° | 34° | — | — |
| 2005 | 51° | 44° | 48° | 0.64" | — |
| 2004 | 43° | 31° | 37° | 1.47" | — |
| 2003 | 39° | 31° | 35° | 0.51" | — |
| 2002 | 47° | 41° | 44° | 3.53" | — |
| 2001 | 45° | 30° | 37° | 0.56" | — |
| 2000 | 46° | 37° | 42° | 0.08" | — |
| 1999 | 44° | 37° | 41° | 0.81" | — |
| 1998 | 54° | 36° | 45° | — | — |
| 1997 | 51° | 37° | 44° | 0.05" | — |
| 1996 | 58° | 48° | 53° | 3.96" | — |
| 1995 | 55° | 40° | 47° | — | — |
| 1994 | 43° | 34° | 38° | — | — |
| 1993 | 44° | 35° | 40° | 1.07" | — |
| 1992 | 38° | 28° | 33° | 0.3" | 1" |
| 1991 | 47° | 31° | 39° | — | — |
| 1990 | 30° | 15° | 23° | — | — |
| 1989 | 44° | 36° | 40° | — | — |
| 1988 | 47° | 34° | 40° | 0.25" | — |
| 1987 | 35° | 23° | 29° | 0.2" | — |
| 1986 | 45° | 36° | 40° | 0.25" | — |
| 1985 | 40° | 30° | 35° | — | — |
| 1984 | 46° | 27° | 36° | — | — |
| 1983 | 37° | 32° | 35° | 0.23" | — |
| 1982 | 41° | 23° | 32° | — | — |
| 1981 | 40° | 31° | 35° | 0.1" | — |
| 1980warmest | 62° | 46° | 54° | 0.05" | — |
| 1979 | 48° | 38° | 43° | 0.76" | — |
| 1978coldest | 21° | 14° | 18° | — | — |
| 1977 | 41° | 30° | 36° | — | — |
| 1976 | 48° | 24° | 36° | — | — |
| 1975 | 45° | 30° | 37° | — | — |
| 1974 | 39° | 32° | 36° | — | — |
| 1973 | 42° | 32° | 37° | 0.08" | — |
| 1972 | 47° | 33° | 40° | — | — |
| 1971 | 43° | 38° | 40° | 0.03" | — |
55 years of data from HILLSBORO