May weather in Rancho Cucamonga, CA
The average temperature in Rancho Cucamonga in May is 67.7°F (55.6°F–79.8°F). Average precipitation: 0.30 inches.
May is a spring month in Rancho Cucamonga, and is warmer than the annual average of 66.8°F. Daily temperatures swing about 24.2°F between overnight low and afternoon high. Expect about 2 days with precipitation. Daylight averages about 13h 47m. For travel, May is one of the best months of the year to visit.
Avg High
79.8°F
Avg Low
55.6°F
Precipitation
0.30 in
Daylight
13h 47m
May records in Rancho Cucamonga
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| May 1 | 93.9°F (2004) | 42.1°F (1999) | 0.03 in (2018) |
| May 2 | 100.9°F (2004) | 46.0°F (1999) | 0.06 in (2003) |
| May 3 | 102.9°F (2004) | 48.0°F (2023) | 0.42 in (2003) |
| May 4 | 95.0°F (2004) | 46.0°F (2001) | 0.70 in (2023) |
| May 5 | 97.0°F (2018) | 45.0°F (1999) | 0.19 in (2025) |
| May 6 | 98.1°F (2020) | 43.0°F (2016) | 1.26 in (2016) |
| May 7 | 99.0°F (2020) | 46.0°F (2017) | 0.35 in (2017) |
| May 8 | 98.1°F (2007) | 44.1°F (2017) | 0.18 in (2015) |
| May 9 | 100.0°F (2025) | 48.9°F (2003) | 0.00 in (1999) |
| May 10 | 102.9°F (2025) | 46.0°F (2003) | 0.00 in (1999) |
| May 11 | 97.0°F (2013) | 46.0°F (2022) | 0.03 in (2009) |
| May 12 | 102.9°F (2013) | 46.9°F (2000) | 0.00 in (1999) |
| May 13 | 102.9°F (2013) | 48.9°F (2000) | 0.00 in (1999) |
| May 14 | 98.1°F (2014) | 50.0°F (2000) | 0.45 in (2015) |
| May 15 | 102.0°F (2014) | 48.9°F (2011) | 0.15 in (2017) |
| May 16 | 100.0°F (2008) | 46.0°F (2011) | 0.35 in (2019) |
| May 17 | 102.0°F (2008) | 45.0°F (2006) | 0.04 in (2011) |
| May 18 | 100.9°F (2008) | 48.9°F (2011) | 0.21 in (2011) |
| May 19 | 97.0°F (2008) | 46.0°F (2011) | 0.18 in (2019) |
| May 20 | 98.1°F (2000) | 51.1°F (2002) | 0.20 in (2002) |
| May 21 | 100.9°F (2000) | 46.9°F (2002) | 0.00 in (1999) |
| May 22 | 96.1°F (2005) | 48.0°F (2002) | 0.43 in (2006) |
| May 23 | 97.0°F (2001) | 50.0°F (2010) | 0.19 in (2008) |
| May 24 | 97.0°F (2021) | 48.0°F (2010) | 0.00 in (1999) |
| May 25 | 91.9°F (2020) | 48.0°F (2010) | 0.00 in (1998) |
| May 26 | 95.0°F (2020) | 48.9°F (2012) | 0.07 in (2019) |
| May 27 | 99.0°F (2000) | 46.0°F (1998) | 0.01 in (2001) |
| May 28 | 102.9°F (2003) | 50.0°F (1998) | 0.00 in (1998) |
| May 29 | 99.0°F (2002) | 48.9°F (2010) | 0.00 in (1998) |
| May 30 | 100.0°F (2025) | 48.9°F (1998) | 0.00 in (1998) |
| May 31 | 96.1°F (2006) | 52.0°F (1998) | 0.00 in (1998) |