- Latitude: 34.1
- Longitude: -117.783
High Temperatures
On May 12 in this location the average high temperature is 77.7 °F (25.4 °C). The lowest recored high temperature was 39.2 °F (4.0 °C) in 1998 and the highest recored high temperature was 102.9 °F (39.4 °C) in 2013. The high temperature is usually* between 71.8 °F (22.1 °C) and 83.7 °F (28.7 °C). About a quarter of the time, the high temperature is less than 71.8 °F (22.1 °C), and another quarter of the time, the high temperature is greater than and 83.7 °F (28.7 °C). About 95% of the time, the high temperature has been between 60.5 °F (15.8 °C) and 95.0 °F (35.0 °C).
Low Temperatures
On May 12 in this location the average low temperature is 54.0 °F (12.2 °C). The lowest recored low temperature was 32.0 °F (0.0 °C) in 1998 and the lowest recored low temperature was 70.0 °F (21.1 °C) in 1996. The low temperature is usually* between 50.6 °F (10.4 °C) and 57.4 °F (14.1 °C). About a quarter of the time, the low temperature is less than 50.6 °F (10.4 °C), and another quarter of the time, the low temperature is greater than and 57.4 °F (14.1 °C). About 95% of the time, the low temperature has been between 44.2 °F (6.8 °C) and 63.8 °F (17.7 °C).
Frost
On May 12 in this location expect the temperatures to drop below freezing for a risk of frost about 0.0% of the time.
Data Source(s)
The data used to compute the average high/low temperatures for this location were taken from the following stations:
- MOUNT WILSON — Integrated Surface Dataset (ISD) station ID: 722890 — Weather Bureau Army Navy (WBAN): 93136 — from year 1980 to 2025
- ONTARIO INTERNATIONAL ARPT — Integrated Surface Dataset (ISD) station ID: 747040 — Weather Bureau Army Navy (WBAN): 03102 — from year 2005 to 2025
- CHINO AIRPORT — Integrated Surface Dataset (ISD) station ID: 722899 — Weather Bureau Army Navy (WBAN): 03179 — from year 2006 to 2025
- FULLERTON MUNICIPAL ARPT — Integrated Surface Dataset (ISD) station ID: 722976 — Weather Bureau Army Navy (WBAN): 03166 — from year 2006 to 2025
- CORONA MUNICIPAL AIRPORT — Integrated Surface Dataset (ISD) station ID: 720333 — Weather Bureau Army Navy (WBAN): 53175 — from year 2011 to 2025
- BRACKETT FIELD AIRPORT — Integrated Surface Dataset (ISD) station ID: 722887 — Weather Bureau Army Navy (WBAN): 03180 — from year 2013 to 2025
- EL MONTE AIRPORT — Integrated Surface Dataset (ISD) station ID: 747043 — Weather Bureau Army Navy (WBAN): 03165 — from year 2012 to 2025
- CABLE — Integrated Surface Dataset (ISD) station ID: 720329 — from year 2018 to 2025
- CORONA MUNI — Integrated Surface Dataset (ISD) station ID: 720333 — from year 2007 to 2017
- FULLERTON MUNICIPAL — Integrated Surface Dataset (ISD) station ID: 722976 — from year 1981 to 2005
- CHINO — Integrated Surface Dataset (ISD) station ID: 722899 — from year 1999 to 2005
- ONTARIO INTL ARPT — Integrated Surface Dataset (ISD) station ID: 747040 — from year 2002 to 2004
- MOUNT WILSON — Integrated Surface Dataset (ISD) station ID: 722890 — from year 2003 to 2003
- ONTARIO — Integrated Surface Dataset (ISD) station ID: 722865 — from year 2000 to 2000
- ONTARIO — Integrated Surface Dataset (ISD) station ID: 722865 — Weather Bureau Army Navy (WBAN): 93180 — from year 1943 to 1999
- ONTARIO INTERNATIONAL ARPT — Weather Bureau Army Navy (WBAN): 03102 — from year 1968 to 1972
- PASADENA — Integrated Surface Dataset (ISD) station ID: 749169 — from year 1944 to 1944