Weather on May 18
Rialto, CA
55 Years of Data
About This Date
May 18th in Rialto, CA typically brings warm spring weather, with average highs around 80°F and lows near 53°F — a 27°F daily swing. Over 49 years of records, the warmest May 18th was in 2008 (84°F average), while the coldest was 2011 (49°F) — a 35°F range across recorded history. Rain or other precipitation has occurred on about 2% of May 18th dates historically, with the wettest May 18th recording 0.61" of rain.
Planning for May 18th in Rialto, CA? Stay hydrated and seek shade during peak afternoon hours.
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2026 | 84° | 55° | 70° | — | — |
| 2025 | 73° | 55° | 64° | — | — |
| 2017 | 79° | 48° | 63° | — | — |
| 2016 | 84° | 54° | 69° | — | — |
| 2015 | 63° | 53° | 58° | — | — |
| 2014 | 78° | 57° | 68° | — | — |
| 2013 | 73° | 55° | 64° | — | — |
| 2012 | 71° | 54° | 62° | — | — |
| 2011coldest | 54° | 45° | 49° | — | — |
| 2010 | 62° | 49° | 55° | — | — |
| 2009 | 91° | 64° | 78° | — | — |
| 2008warmest | 98° | 70° | 84° | — | — |
| 2007 | 82° | 51° | 67° | — | — |
| 2006 | 87° | 57° | 72° | — | — |
| 2005 | 81° | 50° | 65° | — | — |
| 2004 | 74° | 54° | 64° | — | — |
| 2003 | 77° | 51° | 64° | — | — |
| 2002 | 78° | 49° | 63° | — | — |
| 2001 | 79° | 53° | 66° | — | — |
| 2000 | 91° | 54° | 72° | — | — |
| 1999 | 85° | 55° | 70° | — | — |
| 1998 | 81° | 49° | 65° | — | — |
| 1997 | 84° | 59° | 72° | — | — |
| 1996 | 80° | 55° | 68° | — | — |
| 1995 | 79° | 48° | 63° | — | — |
| 1994 | 62° | 48° | 55° | 0.61" | — |
| 1993 | 79° | 55° | 67° | — | — |
| 1992 | 87° | 55° | 71° | — | — |
| 1991 | 64° | 44° | 54° | — | — |
| 1990 | 75° | 54° | 64° | — | — |
| 1989 | 74° | 56° | 65° | — | — |
| 1988 | 82° | 51° | 67° | — | — |
| 1987 | 78° | 59° | 69° | — | — |
| 1986 | 96° | 57° | 77° | — | — |
| 1985 | 80° | 49° | 64° | — | — |
| 1984 | 92° | 55° | 73° | — | — |
| 1983 | 90° | 52° | 71° | — | — |
| 1982 | 79° | 55° | 67° | — | — |
| 1981 | 86° | 45° | 65° | — | — |
| 1980 | 91° | 55° | 73° | — | — |
| 1979 | 83° | 54° | 68° | — | — |
| 1978 | 94° | 52° | 73° | — | — |
| 1977 | 76° | 41° | 58° | — | — |
| 1976 | 89° | 54° | 71° | — | — |
| 1975 | 79° | 53° | 66° | — | — |
| 1974 | 68° | 51° | 60° | — | — |
| 1973 | 88° | 55° | 71° | — | — |
| 1972 | 73° | 53° | 63° | — | — |
| 1971 | 89° | 50° | 70° | — | — |
Rialto, CA Temperature Range by Month
Average monthly highs and lows. The shaded band shows the typical daily temperature range.
Rialto, CA Monthly Precipitation
Average rainfall and snowfall per month, in inches.
Rialto, CA 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 Rialto, CA
Rialto, CA has no months that meet our "pleasant" threshold — every season has tradeoffs.