- Latitude: 34.1
- Longitude: -117.783
High Temperatures
On March 12 in this location the average high temperature is 68.6 °F (20.4 °C). The lowest recored high temperature was 32.0 °F (0.0 °C) in 2006 and the highest recored high temperature was 97.0 °F (36.1 °C) in 2007. The high temperature is usually* between 62.7 °F (17.0 °C) and 74.6 °F (23.7 °C). About a quarter of the time, the high temperature is less than 62.7 °F (17.0 °C), and another quarter of the time, the high temperature is greater than and 74.6 °F (23.7 °C). About 95% of the time, the high temperature has been between 51.3 °F (10.7 °C) and 86.0 °F (30.0 °C).
Low Temperatures
On March 12 in this location the average low temperature is 47.0 °F (8.3 °C). The lowest recored low temperature was 19.4 °F (-7.0 °C) in 2006 and the lowest recored low temperature was 66.2 °F (19.0 °C) in 2013. The low temperature is usually* between 43.2 °F (6.2 °C) and 50.9 °F (10.5 °C). About a quarter of the time, the low temperature is less than 43.2 °F (6.2 °C), and another quarter of the time, the low temperature is greater than and 50.9 °F (10.5 °C). About 95% of the time, the low temperature has been between 35.8 °F (2.1 °C) and 58.2 °F (14.6 °C).
Frost
On March 12 in this location expect the temperatures to drop below freezing for a risk of frost about 0.4% 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 1979 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
- EL MONTE AIRPORT — Integrated Surface Dataset (ISD) station ID: 747043 — Weather Bureau Army Navy (WBAN): 03165 — from year 2013 to 2025
- CABLE — Integrated Surface Dataset (ISD) station ID: 720329 — from year 2018 to 2025
- BRACKETT FIELD AIRPORT — Integrated Surface Dataset (ISD) station ID: 722887 — Weather Bureau Army Navy (WBAN): 03180 — from year 2013 to 2024
- 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 2000 to 2003
- ONTARIO — Integrated Surface Dataset (ISD) station ID: 722865 — from year 2000 to 2001
- 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