- Latitude: 33.975
- Longitude: -117.636
High Temperatures
On December 21 in this location the average high temperature is 66.8 °F (19.4 °C). The lowest recored high temperature was 48.9 °F (9.4 °C) in 1970 and the highest recored high temperature was 87.1 °F (30.6 °C) in 2020. The high temperature is usually* between 61.6 °F (16.5 °C) and 72.0 °F (22.2 °C). About a quarter of the time, the high temperature is less than 61.6 °F (16.5 °C), and another quarter of the time, the high temperature is greater than and 72.0 °F (22.2 °C). About 95% of the time, the high temperature has been between 51.7 °F (11.0 °C) and 82.0 °F (27.8 °C).
Low Temperatures
On December 21 in this location the average low temperature is 41.9 °F (5.5 °C). The lowest recored low temperature was 25.0 °F (-3.9 °C) in 1968 and the lowest recored low temperature was 57.9 °F (14.4 °C) in 2023. The low temperature is usually* between 37.7 °F (3.2 °C) and 46.0 °F (7.8 °C). About a quarter of the time, the low temperature is less than 37.7 °F (3.2 °C), and another quarter of the time, the low temperature is greater than and 46.0 °F (7.8 °C). About 95% of the time, the low temperature has been between 29.9 °F (-1.2 °C) and 53.9 °F (12.1 °C).
Frost
On December 21 in this location expect the temperatures to drop below freezing for a risk of frost about 5.4% 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:
- 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
- FULLERTON MUNICIPAL ARPT — Integrated Surface Dataset (ISD) station ID: 722976 — Weather Bureau Army Navy (WBAN): 03166 — 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
- CABLE — Integrated Surface Dataset (ISD) station ID: 720329 — from year 2017 to 2024
- CORONA MUNI — Integrated Surface Dataset (ISD) station ID: 720333 — from year 2006 to 2016
- 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 1942 to 1999
- ONTARIO INTERNATIONAL ARPT — Weather Bureau Army Navy (WBAN): 03102 — from year 1968 to 1972