Climate - Riverside (California)

The climate of Riverside is arid subtropical, with very mild, relatively rainy winters and very hot, sunny summers.
The city is located at 250 meters (820 ft) above sea level, 90 km (55 mi) east of Los Angeles, and south-east of San Bernardino, in an area far enough from the ocean to be very hot in summer.
In winter, however, sometimes it can get cold at night, although in general the temperature only reaches the freezing mark on the coldest nights of the year. In January 2007 it dropped to -4.4 °C (24 °F). Due to its location in an area surrounded by mountains, the city is also subject to air stagnation and therefore pollution.
In summer, the temperature can exceed 40 °C (104 °F) on the hottest days, and sometimes it can reach 44/45 °C (111/113 °F). In July 2018, it reached 47.8 °C (118 °F), while in September 2020 it reached 47.2 °C (117 °C).
The average temperature of the coldest month (December) is of 12.7 °C (54.8 °F), that of the warmest month (August) is of 26.6 °C (79.8 °F). Here are the average temperatures.

Precipitation amounts to 240 millimeters (9.4 inches) per year: it is therefore scarce (although in winter there may be periods of bad weather). It ranges from 0 mm (0 in) in the driest months (June, August) to 60 mm (2.4 in) in the wettest ones (January, February). Here is the average precipitation.

Best Time

To visit Riverside, you can choose the periods from mid-March to mid-April and from mid-October to mid-November. In winter, the weather is often mild and sunny, but sometimes it can be cold at night, and it can also rain.

Back to California.

Riverside - Weather by month

Based on the period 1991-2020

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In January, the weather in Riverside is usually mild. However, there are remarkable differences between night and day. The average temperature is of 13.1 °C (56 °F), with a minimum of 6.4 °C (43.6 °F) and a maximum of 19.8 °C (67.7 °F).
On the coldest nights of the month, the temperature usually drops to around 1 °C (33.5 °F).
On the warmest days of the month, the temperature usually reaches around 28.5 °C (83 °F).
Precipitation amounts to 60 mm (2.4 in), distributed over 5 days.
The day lasts on average 10 hours and 10 minutes.
The average humidity is 50%.
The average wind speed is 8 kph (5 mph).

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In February, the weather in Riverside is usually mild. The average temperature is of 13.5 °C (56 °F), with a minimum of 7.1 °C (44.7 °F) and a maximum of 19.9 °C (67.9 °F).
On the coldest nights of the month, the temperature usually drops to around 1.5 °C (34.5 °F).
On the warmest days of the month, the temperature usually reaches around 29.5 °C (85 °F).
Precipitation amounts to 60 mm (2.4 in), distributed over 7 days.
The day lasts on average 11 hours and 0 minutes.
The average humidity is 55%.
The average wind speed is 7 kph (5 mph).

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In March, the weather in Riverside is usually very mild. However, there are remarkable differences between night and day. The average temperature is of 15.3 °C (60 °F), with a minimum of 8.3 °C (46.9 °F) and a maximum of 22.3 °C (72.1 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 3 °C (37.5 °F).
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 31 °C (88 °F).
Precipitation amounts to 30 mm (1.2 in), distributed over 5 days.
The day lasts on average 12 hours and 0 minutes.
The average humidity is 57%.
The average wind speed is 8 kph (5 mph).

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In April, the weather in Riverside is usually very mild. However, there are remarkable differences between night and day. The average temperature is of 17.2 °C (63 °F), with a minimum of 10 °C (50 °F) and a maximum of 24.4 °C (75.9 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 5 °C (41 °F).
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 34.5 °C (94.5 °F).
Precipitation amounts to 15 mm (0.6 in), distributed over 4 days.
The day lasts on average 13 hours and 5 minutes.
The average humidity is 55%.
The average wind speed is 8 kph (5 mph).

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In May, the weather in Riverside is usually warm. However, there are remarkable differences between night and day. The average temperature is of 19.8 °C (68 °F), with a minimum of 12.9 °C (55.3 °F) and a maximum of 26.6 °C (79.9 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 8.5 °C (47 °F).
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 36 °C (97 °F).
Precipitation amounts to only 5 mm (0.2 in), distributed over 2 days.
The day lasts on average 14 hours and 0 minutes.
The average humidity is 57%.
The average wind speed is 9 kph (5 mph).

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In June, the weather in Riverside is usually warm to hot. However, there are remarkable differences between night and day. The average temperature is of 22.8 °C (73 °F), with a minimum of 15.2 °C (59.3 °F) and a maximum of 30.4 °C (86.7 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 11.5 °C (53 °F).
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 38 °C (100.5 °F).
Precipitation amounts to only 0 mm (0 in), so on average it never rains in the whole month.
The day lasts on average 14 hours and 25 minutes. So the days are long. June 21, the summer solstice, is the longest day of the year in the Northern Hemisphere.
The average humidity is 56%.
The average wind speed is 9 kph (6 mph).

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In July, the weather in Riverside is usually warm to hot. However, there are remarkable differences between night and day. The average temperature is of 25.9 °C (79 °F), with a minimum of 17.7 °C (63.9 °F) and a maximum of 34.1 °C (93.3 °F).
On the coldest nights of the month, the temperature usually drops to around 14 °C (57.5 °F).
On the warmest days of the month, the temperature usually reaches around 40.5 °C (105 °F).
Precipitation amounts to only 5 mm (0.2 in), and all occurs in one day.
The day lasts on average 14 hours and 5 minutes. So the days are long.
The average humidity is 52%.
The average wind speed is 9 kph (5 mph).

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In August, the warmest month of the year, the weather in Riverside is usually warm to hot. However, there are remarkable differences between night and day. The average temperature is of 26.6 °C (80 °F), with a minimum of 18.2 °C (64.7 °F) and a maximum of 34.9 °C (94.9 °F).
On the coldest nights of the month, the temperature usually drops to around 14.5 °C (58 °F).
On the warmest days of the month, the temperature usually reaches around 41 °C (105.5 °F).
Precipitation amounts to only 0 mm (0 in), so on average it never rains in the whole month.
The day lasts on average 13 hours and 20 minutes.
The average humidity is 50%.
The average wind speed is 8 kph (5 mph).

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In September, the weather in Riverside is usually warm to hot. However, there are remarkable differences between night and day. The average temperature is of 24.8 °C (77 °F), with a minimum of 16.6 °C (61.9 °F) and a maximum of 32.9 °C (91.3 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 12 °C (54 °F).
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 41.5 °C (106.5 °F).
Precipitation amounts to only 5 mm (0.2 in), distributed over 0 days.
The day lasts on average 12 hours and 20 minutes.
The average humidity is 51%.
The average wind speed is 7 kph (4 mph).

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In October, the weather in Riverside is usually warm. However, there are remarkable differences between night and day. The average temperature is of 20.5 °C (69 °F), with a minimum of 12.9 °C (55.2 °F) and a maximum of 28.2 °C (82.7 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 8.5 °C (47.5 °F).
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 37.5 °C (99.5 °F).
Precipitation amounts to 10 mm (0.4 in), distributed over 2 days.
The day lasts on average 11 hours and 20 minutes.
The average humidity is 51%.
The average wind speed is 7 kph (4 mph).

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In November, the weather in Riverside is usually very mild. However, there are remarkable differences between night and day. The average temperature is of 16.1 °C (61 °F), with a minimum of 8.6 °C (47.4 °F) and a maximum of 23.6 °C (74.5 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 3 °C (37.5 °F).
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 32.5 °C (90.5 °F).
Precipitation amounts to 15 mm (0.6 in), distributed over 4 days.
The day lasts on average 10 hours and 25 minutes.
The average humidity is 49%.
The average wind speed is 7 kph (4 mph).

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In December, the coldest month of the year, the weather in Riverside is usually mild. However, there are remarkable differences between night and day. The average temperature is of 12.7 °C (55 °F), with a minimum of 6 °C (42.8 °F) and a maximum of 19.3 °C (66.8 °F).
On the coldest nights of the month, the temperature usually drops to around 0.5 °C (32.5 °F).
On the warmest days of the month, the temperature usually reaches around 27.5 °C (82 °F).
Precipitation amounts to 40 mm (1.6 in), distributed over 5 days.
The day lasts on average 9 hours and 55 minutes. December 21, the winter solstice, is the shortest day of the year in the Northern Hemisphere.
The average humidity is 50%.
The average wind speed is 8 kph (5 mph).