- Latitude: 34.112
- Longitude: -117.688
High Temperatures
On September 18 in this location the average high temperature is 87.7 °F (30.9 °C). The lowest recored high temperature was 73.9 °F (23.3 °C) in 1955 and the highest recored high temperature was 107.1 °F (41.7 °C) in 2016. The high temperature is usually* between 82.2 °F (27.9 °C) and 93.1 °F (34.0 °C). About a quarter of the time, the high temperature is less than 82.2 °F (27.9 °C), and another quarter of the time, the high temperature is greater than and 93.1 °F (34.0 °C). About 95% of the time, the high temperature has been between 71.9 °F (22.1 °C) and 103.5 °F (39.7 °C).
Low Temperatures
On September 18 in this location the average low temperature is 60.0 °F (15.5 °C). The lowest recored low temperature was 41.9 °F (5.5 °C) in 2006 and the lowest recored low temperature was 77.0 °F (25.0 °C) in 2020. The low temperature is usually* between 56.0 °F (13.3 °C) and 64.0 °F (17.8 °C). About a quarter of the time, the low temperature is less than 56.0 °F (13.3 °C), and another quarter of the time, the low temperature is greater than and 64.0 °F (17.8 °C). About 95% of the time, the low temperature has been between 48.3 °F (9.0 °C) and 71.7 °F (22.1 °C).
Frost
On September 18 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:
- ONTARIO INTERNATIONAL ARPT — Integrated Surface Dataset (ISD) station ID: 747040 — Weather Bureau Army Navy (WBAN): 03102 — from year 2005 to 2024
- RIVERSIDE MUNICIPAL ARPT — Integrated Surface Dataset (ISD) station ID: 722869 — Weather Bureau Army Navy (WBAN): 03171 — from year 2006 to 2024
- CHINO AIRPORT — Integrated Surface Dataset (ISD) station ID: 722899 — Weather Bureau Army Navy (WBAN): 03179 — from year 2006 to 2024
- CORONA MUNICIPAL AIRPORT — Integrated Surface Dataset (ISD) station ID: 720333 — Weather Bureau Army Navy (WBAN): 53175 — from year 2011 to 2024
- BRACKETT FIELD AIRPORT — Integrated Surface Dataset (ISD) station ID: 722887 — Weather Bureau Army Navy (WBAN): 03180 — from year 2012 to 2024
- EL MONTE AIRPORT — Integrated Surface Dataset (ISD) station ID: 747043 — Weather Bureau Army Navy (WBAN): 03165 — from year 2012 to 2024
- CABLE — Integrated Surface Dataset (ISD) station ID: 720329 — from year 2018 to 2024
- CORONA MUNI — Integrated Surface Dataset (ISD) station ID: 720333 — from year 2006 to 2017
- RIVERSIDE MUNI — Integrated Surface Dataset (ISD) station ID: 722869 — from year 1998 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 2001 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