Weather on March 31
Ontario, CA
55 Years of Data
Avg High
72°F
Avg Low
48°F
Warmest
2011
75°F avg
Coldest
1977
44°F avg
About This Date
March 31st in Ontario, CA typically brings pleasant spring weather, with average highs around 72°F and lows near 48°F. Over 42 years of records, the warmest March 31st was in 2011 (75°F average), while the coldest was 1977 (44°F) — a 31°F range across recorded history. Rain or other precipitation has occurred on about 14% of March 31st dates historically, with the wettest March 31st recording 2.97" of rain. The last decade has been 1.6°F cooler on this date compared to 20-30 years ago.
The last decade has been 1.6°F cooler on this date compared to 20-30 years ago.
Planning for March 31st in Ontario, CA? Great weather for outdoor activities.
Warming Trend
1.7°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2026 | 70° | 60° | 65° | 0.64" | — |
| 2025 | 69° | 53° | 61° | 0.05" | — |
| 2024 | 56° | 48° | 52° | 0.84" | — |
| 2023 | 66° | 41° | 54° | — | — |
| 2022 | 64° | 54° | 59° | — | — |
| 2021 | 87° | 59° | 73° | — | — |
| 2020 | 78° | 50° | 64° | — | — |
| 2019 | 89° | 51° | 70° | — | — |
| 2018 | 82° | 54° | 68° | — | — |
| 2017 | 71° | 48° | 60° | — | — |
| 2016 | 73° | 45° | 59° | — | — |
| 2015 | 80° | 53° | 67° | — | — |
| 2014 | 69° | 48° | 59° | — | — |
| 2013 | 72° | 52° | 62° | — | — |
| 2012 | 61° | 49° | 55° | 0.18" | — |
| 2011warmest | 93° | 57° | 75° | — | — |
| 2010 | 60° | 46° | 53° | 0.08" | — |
| 2009 | 75° | 47° | 61° | — | — |
| 2008 | 66° | 44° | 55° | — | — |
| 2007 | 82° | 50° | 66° | — | — |
| 2006 | 60° | 49° | 54° | — | — |
| 2005 | 78° | 51° | 65° | — | — |
| 2004 | 75° | 51° | 63° | — | — |
| 2003 | 87° | 54° | 70° | — | — |
| 2002 | 80° | 48° | 64° | — | — |
| 2001 | 77° | 55° | 66° | — | — |
| 2000 | 78° | 53° | 66° | — | — |
| 1999 | 59° | 47° | 53° | — | — |
| 1984 | 64° | 38° | 51° | — | — |
| 1983 | 73° | 45° | 59° | — | — |
| 1982 | 63° | 36° | 49° | — | — |
| 1981 | 77° | 41° | 59° | — | — |
| 1980 | 67° | 44° | 55° | — | — |
| 1979 | 71° | 38° | 54° | — | — |
| 1978 | 61° | 50° | 55° | 2.97" | — |
| 1977coldest | 55° | 33° | 44° | — | — |
| 1976 | 78° | 48° | 63° | — | — |
| 1975 | 67° | 38° | 52° | — | — |
| 1974 | 67° | 44° | 55° | — | — |
| 1973 | 58° | 45° | 51° | — | — |
| 1972 | 79° | 43° | 61° | — | — |
| 1971 | 73° | 45° | 59° | — | — |
42 years of data from ONTARIO INTL AP