Weather on May 28
Ontario, CA
55 Years of Data
Avg High
81°F
Avg Low
55°F
Warmest
2003
84°F avg
Coldest
1971
51°F avg
About This Date
May 28th in Ontario, CA typically brings warm spring weather, with average highs around 81°F and lows near 55°F — a 26°F daily swing. Over 42 years of records, the warmest May 28th was in 2003 (84°F average), while the coldest was 1971 (51°F) — a 33°F range across recorded history. Rain or other precipitation has occurred on about 2% of May 28th dates historically. The last decade has been 2.2°F cooler on this date compared to 20-30 years ago.
The last decade has been 2.2°F cooler on this date compared to 20-30 years ago.
Planning for May 28th in Ontario, CA? Stay hydrated and seek shade during peak afternoon hours.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 76° | 60° | 68° | — | — |
| 2024 | 80° | 54° | 67° | — | — |
| 2023 | 68° | 56° | 62° | — | — |
| 2022 | 68° | 56° | 62° | — | — |
| 2021 | 86° | 56° | 71° | — | — |
| 2020 | 88° | 60° | 74° | — | — |
| 2019 | 79° | 50° | 64° | — | — |
| 2018 | 86° | 55° | 71° | — | — |
| 2017 | 87° | 55° | 71° | — | — |
| 2016 | 79° | 56° | 67° | — | — |
| 2015 | 85° | 54° | 69° | — | — |
| 2014 | 89° | 62° | 76° | — | — |
| 2013 | 77° | 59° | 68° | — | — |
| 2012 | 89° | 56° | 72° | — | — |
| 2011 | 73° | 54° | 63° | — | — |
| 2010 | 73° | 50° | 62° | — | — |
| 2009 | 83° | 59° | 71° | — | — |
| 2008 | 76° | 51° | 63° | — | — |
| 2007 | 79° | 55° | 67° | — | — |
| 2006 | 79° | 50° | 64° | — | — |
| 2005 | 77° | 59° | 68° | — | — |
| 2004 | 67° | 58° | 62° | — | — |
| 2003warmest | 103° | 65° | 84° | — | — |
| 2002 | 84° | 52° | 68° | — | — |
| 2001 | 69° | 59° | 64° | — | — |
| 2000 | 97° | 64° | 80° | — | — |
| 1999 | 82° | 57° | 70° | — | — |
| 1998 | 76° | 50° | 63° | — | — |
| 1984 | 106° | 56° | 81° | — | — |
| 1983 | 92° | 57° | 74° | — | — |
| 1982 | 72° | 56° | 64° | — | — |
| 1981 | 80° | 58° | 69° | — | — |
| 1980 | 64° | 47° | 55° | — | — |
| 1979 | 72° | 57° | 64° | — | — |
| 1978 | 98° | 56° | 77° | — | — |
| 1977 | 75° | 47° | 61° | — | — |
| 1976 | 74° | 54° | 64° | — | — |
| 1975 | 82° | 53° | 68° | — | — |
| 1974 | 80° | 53° | 67° | — | — |
| 1973 | 100° | 60° | 80° | — | — |
| 1972 | 96° | 46° | 71° | — | — |
| 1971coldest | 55° | 46° | 51° | 0.28" | — |
42 years of data from ONTARIO INTL AP