As of 02:25 PDT

Rialto, CA weather in September

77°

Rialto, Sunday, 9 August, 02:25

Partly cloudy. Feels like 76°. High 101°, low 73°.

Pressure29.88 inHg

Wind1.6 mph NW

Humidity40%

Visibility6.2 mi

Dew point51°

See detailed hourly forecast

In September, Rialto, CA averages a high of 87.5° and a low of 62.1°. About 0.4 inches of precipitation fall over the month (1 wet days). The record high is 115° (2020) and the record low 45.9° (1965). Normals are computed over the last 60 years.

Day	High	Low	Chance of precip.	Record high	Record low
1	91.8°	65.1°	5%	107.1° (2022)	53.4° (1964)
2	91.9°	65.5°	8%	105.6° (2007)	49.8° (1964)
3	91.4°	66°	5%	108° (2022)	54.3° (1964)
4	91.9°	66°	2%	108° (2022)	54.3° (1985)
5	91.9°	66.4°	3%	113° (2020)	55.9° (2016)
6	91.9°	65.7°	3%	115° (2020)	53.6° (2000)
7	91.2°	65.8°	3%	108.5° (2024)	51.8° (1965)
8	90.3°	65.3°	2%	106.3° (2024)	47.8° (1965)
9	88.9°	64.6°	5%	106.3° (2024)	50.7° (1965)
10	87.6°	63.9°	7%	102.4° (1993)	51.8° (2010)
11	87.4°	62.8°	7%	102.4° (1971)	49.5° (1985)
12	87.1°	62.2°	2%	105.4° (1971)	48° (1985)
13	86.4°	61.7°	7%	106.3° (1971)	50.4° (1972)
14	86.5°	61.2°	3%	102.7° (2014)	51.1° (1970)
15	86.4°	61.2°	8%	103.1° (2014)	50.7° (1970)
16	85.8°	61.5°	7%	103.8° (2000)	52° (1986)
17	85.6°	61.2°	2%	100.4° (2000)	51.4° (2005)
18	85.3°	60.6°	3%	100.9° (2020)	48.4° (1993)
19	84.4°	59.7°	3%	97.3° (2016)	47.7° (1978)
20	84°	59.9°	10%	100.6° (2015)	45.9° (1965)
21	84.9°	58.6°	5%	99.5° (2021)	47.5° (1965)
22	85.8°	59.4°	3%	99.3° (2002)	49.8° (1968)
23	86.9°	59.7°	3%	101.5° (2002)	50.2° (1986)
24	86.9°	60.1°	3%	100.4° (2015)	50° (1986)
25	86.2°	60.4°	5%	102.2° (2010)	49.3° (2005)
26	85.3°	60.1°	10%	103.5° (2010)	49.1° (1971)
27	85.6°	59.7°	5%	105.8° (2010)	47.3° (2013)
28	85.5°	59.9°	2%	100.9° (2020)	46.8° (1971)
29	84.7°	60.1°	10%	102.2° (2020)	46° (1986)
30	85.5°	59°	3%	103.8° (2020)	47.3° (1982)