- Latitude: 34.1
- Longitude: -117.25
High Temperatures
On September 1 in this location the average high temperature is 93.9 °F (34.4 °C). The lowest recored high temperature was 73.0 °F (22.8 °C) in 1942 and the highest recored high temperature was 114.1 °F (45.6 °C) in 2017. The high temperature is usually* between 88.8 °F (31.5 °C) and 99.0 °F (37.2 °C). About a quarter of the time, the high temperature is less than 88.8 °F (31.5 °C), and another quarter of the time, the high temperature is greater than and 99.0 °F (37.2 °C). About 95% of the time, the high temperature has been between 79.0 °F (26.1 °C) and 108.8 °F (42.7 °C).
Low Temperatures
On September 1 in this location the average low temperature is 62.3 °F (16.8 °C). The lowest recored low temperature was 48.2 °F (9.0 °C) in 1999 and the lowest recored low temperature was 105.1 °F (40.6 °C) in 1987. The low temperature is usually* between 58.0 °F (14.5 °C) and 66.6 °F (19.2 °C). About a quarter of the time, the low temperature is less than 58.0 °F (14.5 °C), and another quarter of the time, the low temperature is greater than and 66.6 °F (19.2 °C). About 95% of the time, the low temperature has been between 49.9 °F (9.9 °C) and 74.8 °F (23.8 °C).
Frost
On September 1 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:
- MARCH AIR RESERVE BASE — Integrated Surface Dataset (ISD) station ID: 722860 — Weather Bureau Army Navy (WBAN): 23119 — from year 1933 to 2024
- 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
- SAN BERNARDINO INTL — Integrated Surface Dataset (ISD) station ID: 722866 — from year 2009 to 2024
- NORTON AAF — Weather Bureau Army Navy (WBAN): 23122 — from year 2014 to 2023
- SAN BERNARDINO INTERNATIONAL — Integrated Surface Dataset (ISD) station ID: 722866 — Weather Bureau Army Navy (WBAN): 23122 — from year 1943 to 2013
- RIVERSIDE MUNI — Integrated Surface Dataset (ISD) station ID: 722869 — from year 1998 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 2001 to 2004
- BEAUMONT — Integrated Surface Dataset (ISD) station ID: 722867 — from year 2000 to 2001
- 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
- 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 1952