- Latitude: 34.1
- Longitude: -117.25
High Temperatures
On January 20 in this location the average high temperature is 64.8 °F (18.2 °C). The lowest recored high temperature was 42.4 °F (5.8 °C) in 1933 and the highest recored high temperature was 84.9 °F (29.4 °C) in 1971. The high temperature is usually* between 58.9 °F (15.0 °C) and 70.6 °F (21.5 °C). About a quarter of the time, the high temperature is less than 58.9 °F (15.0 °C), and another quarter of the time, the high temperature is greater than and 70.6 °F (21.5 °C). About 95% of the time, the high temperature has been between 47.8 °F (8.8 °C) and 81.8 °F (27.7 °C).
Low Temperatures
On January 20 in this location the average low temperature is 41.4 °F (5.2 °C). The lowest recored low temperature was 24.1 °F (-4.4 °C) in 2008 and the lowest recored low temperature was 57.9 °F (14.4 °C) in 1976. The low temperature is usually* between 37.3 °F (2.9 °C) and 45.6 °F (7.5 °C). About a quarter of the time, the low temperature is less than 37.3 °F (2.9 °C), and another quarter of the time, the low temperature is greater than and 45.6 °F (7.5 °C). About 95% of the time, the low temperature has been between 29.3 °F (-1.5 °C) and 53.5 °F (11.9 °C).
Frost
On January 20 in this location expect the temperatures to drop below freezing for a risk of frost about 6.3% 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:
- MARCH AIR RESERVE BASE — Integrated Surface Dataset (ISD) station ID: 722860 — Weather Bureau Army Navy (WBAN): 23119 — from year 1933 to 2025
- NORTON AAF — Weather Bureau Army Navy (WBAN): 23122 — from year 2015 to 2025
- ONTARIO INTERNATIONAL ARPT — Integrated Surface Dataset (ISD) station ID: 747040 — Weather Bureau Army Navy (WBAN): 03102 — from year 2005 to 2025
- RIVERSIDE MUNICIPAL ARPT — Integrated Surface Dataset (ISD) station ID: 722869 — Weather Bureau Army Navy (WBAN): 03171 — from year 2006 to 2025
- SAN BERNARDINO INTL — Integrated Surface Dataset (ISD) station ID: 722866 — from year 2009 to 2025
- SAN BERNARDINO INTERNATIONAL — Integrated Surface Dataset (ISD) station ID: 722866 — Weather Bureau Army Navy (WBAN): 23122 — from year 1943 to 2014
- RIVERSIDE MUNI — Integrated Surface Dataset (ISD) station ID: 722869 — from year 1999 to 2005
- RIVERSIDE/MARCH AFB — Integrated Surface Dataset (ISD) station ID: 722860 — from year 2000 to 2004
- 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 2001
- BEAUMONT — Integrated Surface Dataset (ISD) station ID: 722867 — from year 2000 to 2001
- ONTARIO — Integrated Surface Dataset (ISD) station ID: 722865 — Weather Bureau Army Navy (WBAN): 93180 — from year 1943 to 1999
- BEAUMONT — Integrated Surface Dataset (ISD) station ID: 722867 — Weather Bureau Army Navy (WBAN): 23156 — from year 1973 to 1999
- ONTARIO INTERNATIONAL ARPT — Weather Bureau Army Navy (WBAN): 03102 — from year 1968 to 1972
- BEAUMONT 1 E — Weather Bureau Army Navy (WBAN): 23156 — from year 1948 to 1953