- Latitude: 34.1
- Longitude: -117.783
High Temperatures
On June 23 in this location the average high temperature is 85.2 °F (29.5 °C). The lowest recored high temperature was 64.4 °F (18.0 °C) in 2025 and the highest recored high temperature was 106.9 °F (41.6 °C) in 1973. The high temperature is usually* between 80.1 °F (26.7 °C) and 90.2 °F (32.3 °C). About a quarter of the time, the high temperature is less than 80.1 °F (26.7 °C), and another quarter of the time, the high temperature is greater than and 90.2 °F (32.3 °C). About 95% of the time, the high temperature has been between 70.5 °F (21.4 °C) and 99.8 °F (37.7 °C).
Low Temperatures
On June 23 in this location the average low temperature is 59.8 °F (15.5 °C). The lowest recored low temperature was 41.0 °F (5.0 °C) in 2019 and the lowest recored low temperature was 75.2 °F (24.0 °C) in 2024. The low temperature is usually* between 57.3 °F (14.0 °C) and 62.4 °F (16.9 °C). About a quarter of the time, the low temperature is less than 57.3 °F (14.0 °C), and another quarter of the time, the low temperature is greater than and 62.4 °F (16.9 °C). About 95% of the time, the low temperature has been between 52.4 °F (11.3 °C) and 67.3 °F (19.6 °C).
Frost
On June 23 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 1998 to 2005
- ONTARIO INTL ARPT — Integrated Surface Dataset (ISD) station ID: 747040 — from year 2002 to 2004
- 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