Weather on April 18
Ontario, CA
55 Years of Data
Avg High
74°F
Avg Low
49°F
Warmest
2019
75°F avg
Coldest
1971
49°F avg
About This Date
April 18th in Ontario, CA typically brings pleasant spring weather, with average highs around 74°F and lows near 49°F — a 25°F daily swing. Over 42 years of records, the warmest April 18th was in 2019 (75°F average), while the coldest was 1971 (49°F) — a 26°F range across recorded history. Rain or other precipitation has occurred on about 17% of April 18th dates historically, with the wettest April 18th recording 1.68" of rain. The last decade has been 6.3°F warmer on this date compared to 20-30 years ago.
The last decade has been 6.3°F warmer on this date compared to 20-30 years ago.
Planning for April 18th in Ontario, CA? Great weather for outdoor activities.
Warming Trend
2.0°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 59° | 50° | 55° | 0.03" | — |
| 2024 | 78° | 53° | 66° | — | — |
| 2023 | 64° | 49° | 56° | — | — |
| 2022 | 82° | 53° | 68° | — | — |
| 2021 | 88° | 54° | 71° | — | — |
| 2020 | 63° | 52° | 57° | 0.08" | — |
| 2019warmest | 93° | 57° | 75° | — | — |
| 2018 | 77° | 50° | 64° | — | — |
| 2017 | 76° | 61° | 68° | — | — |
| 2016 | 91° | 57° | 74° | — | — |
| 2015 | 84° | 54° | 69° | — | — |
| 2014 | 75° | 58° | 66° | — | — |
| 2013 | 79° | 48° | 63° | — | — |
| 2012 | 81° | 53° | 67° | — | — |
| 2011 | 63° | 56° | 59° | — | — |
| 2010 | 80° | 51° | 66° | — | — |
| 2009 | 88° | 50° | 69° | — | — |
| 2008 | 87° | 55° | 71° | — | — |
| 2007 | 70° | 49° | 59° | — | — |
| 2006 | 79° | 45° | 62° | — | — |
| 2005 | 63° | 53° | 58° | — | — |
| 2004 | 67° | 46° | 56° | — | — |
| 2003 | 62° | 48° | 55° | — | — |
| 2002 | 66° | 43° | 54° | — | — |
| 2001 | 74° | 52° | 63° | — | — |
| 2000 | 61° | 47° | 54° | 1.68" | — |
| 1999 | 92° | 54° | 73° | — | — |
| 1998 | 81° | 39° | 60° | — | — |
| 1984 | 70° | 50° | 60° | — | — |
| 1983 | 64° | 50° | 57° | 1.14" | — |
| 1982 | 79° | 43° | 61° | — | — |
| 1981 | 65° | 52° | 58° | — | — |
| 1980 | 91° | 55° | 73° | — | — |
| 1979 | 66° | 40° | 53° | — | — |
| 1978 | 73° | 45° | 59° | — | — |
| 1977 | 74° | 49° | 61° | — | — |
| 1976 | 68° | 39° | 54° | — | — |
| 1975 | 64° | 36° | 50° | — | — |
| 1974 | 71° | 46° | 59° | — | — |
| 1973 | 69° | 42° | 56° | 0.08" | — |
| 1972 | 58° | 45° | 51° | 0.3" | — |
| 1971coldest | 60° | 38° | 49° | 0.25" | — |
42 years of data from ONTARIO INTL AP