Climate and monthly weather forecastRiverside, CA
Climate and monthly weather forecast
The climate of Riverside
Positioned in Southern California, Riverside owns a Mediterranean climate, marked as a hot-summer version by the Köppen climate classification (Csa). The climate here is characterized by hot, sunny summers, and mild, wet winters. The temperature in Riverside ranges from an average low of 45.9°F (7.7°C) in the coldest month, December, to an average high of 91.2°F (32.9°C) in the hottest month, August.Temperature fluctuations in Riverside are relatively regular, with the highest changes usually observed in summer months. Average highs escalate from 65.3°F (18.5°C) in January to a peak of 91.2°F (32.9°C) in August, while the average lows increase from 47.3°F (8.5°C) in January to a warmest low of 66.4°F (19.1°C) in August. The average relative humidity varies slightly over the year, with the lowest humidity registered in August at 43%, and the highest in the wet month of April, at 56%.
Predominantly clear skies dominate Riverside, with average cloud cover percentage bestowing more bright days than dark ones. The smallest cloud cover in Riverside is 5% in August, while the highest is 23% in both February and March, allowing ample daylight throughout the year.
Riverside's unique weather pattern is its scarce rainfall during the peak summer months. The city receives the least amount of rainfall, 0.04" (1mm), in the dry month of June. Conversely, February is marked by the highest rainfall, 1.61" (41mm), making it the wettest month.
The best time to visit Riverside
The optimal period to visit Riverside for favorable weather is from April to June. During these months, the temperatures are pleasurably warm, ranging from an average high of 73°F (22.8°C) in April to 84.2°F (29°C) in June, and an average low from 50.5°F (10.3°C) to 58.6°F (14.8°C). The periods of daylight are generously long, with approximately 13 hours per day between April and June.In addition, relative humidity is comfortably balanced during this time. The rainfall is minimal, predominantly in the earlier spring months, reducing the chances of weather disruptions during tourist activities.
The worst time to visit Riverside
The least desirable time for a visit would be the hot summer months, specifically July and August. During this time, the temperatures can climb to average highs of over 90°F (32.2°C), making outdoor activities potentially uncomfortable. Additionally, these months have the lowest relative humidity, dropping to 46% and 43% each, resulting in quite dry conditions.Spring weather in Riverside
Spring in Riverside, from March to May, presents a gentle transition from the cooler winter months to the hotter summer timeframe. The average temperatures rise gradually, with high temperatures from 68.7°F (20.4°C) in March to 76.6°F (24.8°C) in May, and low temperatures increasing from 47.5°F (8.6°C) to 54°F (12.2°C).In these months, relative humidity rates hover around mid-fifties. Rainfall diminishes substantially from March to May with a significant drop from 0.87" (22mm) to 0.2" (5mm). The duration of daylight steadily extends from 12 hours in March to nearly 14 hours in May.
Summer weather in Riverside
Summer in Riverside is hot and dry. From June to August, the average high temperature escalates from 84.2°F (29°C) to a peak of 91.2°F (32.9°C). The average low temperature varies from 58.6°F (14.8°C) to 66.4°F (19.1°C), reflecting warm nights. Relative humidity descends to its yearly lowest point, and rainfall is minimal, providing conditions ideal for outdoor activities, particularly water sports.Autumn weather in Riverside
Autumn in Riverside is quite pleasant, with cooling temperatures and modest amounts of rainfall. Starting from September to November, the average high temperature descends from a warm 88.3°F (31.3°C) to a more moderate 71.4°F (21.9°C). The low temperatures experience a similar decline, from 64°F (17.8°C) to 52°F (11.1°C).Winter weather in Riverside
Winter in Riverside is mild and a little wetter than other seasons. The average high temperatures are between 65.3°F (18.5°C) in January and 63.3°F (17.4°C) in December. The average low temperatures decrease from 47.5°F (8.6°C) in January to 45.9°F (7.7°C) in December. The amount of daylight shortens to approximately 10 hours, and noticeable increases in rainfall make this season the wettest with 1.61" (41mm) precipitation in both January and December.Weather in January
January in Riverside, California sees the low end of annual temperature swings. The bulk of the days are brightly-lit, receiving over six hours of sunshine. Despite milder average temperatures, the month is equipped with a UV index of four, enabling individuals to bask in the sunlight. Weather in January »Weather in February
Contrary to January, February sees an incremental increase in rainfall, recording 1.61" (41mm), marking February as one of the wetter months in Riverside, California. Temperatures remain stable, slight variations notwithstanding. Weather in February »Weather in March
March's temperatures rise slightly in Riverside in anticipation of spring. With spring's arrival, rainfall diminishes down to 0.87" (22mm), suggestive of efflorescence throughout the city. Sunlight increases by an hour from February, illuminating sweeping landscapes of the city. Weather in March »Weather in April
April sheds some of winter's leftover rains, with rainfall dropping to 0.63" (16mm). Riverside's temperature ascends in April with residents and tourists alike appreciating milder climate conditions. The winds pick up a bit from the preceding month, adding a pleasant breeze to the warming days. Weather in April »Weather in May
In May, Riverside experiences minimal rainfall of only 0.2" (5mm), compelling locals and visitors to venture outdoors. Temperatures experience a more considerable increase, reflective of the city’s transition to summer. The average visibility remains consistent, permitting uninterrupted viewing of Riverside's various attractions. Weather in May »Weather in June
As Riverside steps into June, temperatures undergo a substantial climb while maintaining a steady humidity level. Rainfall decreases further to 0.04" (1mm), marking June as the driest month of the year. The lack of rainy days and prevalent sunshine create an inviting atmosphere for outdoor activities. Weather in June »Weather in July
July amplifies Riverside's summer sensation with recorded high temperatures hitting 90.1°F (32.3°C). Humidity drops, reflecting the lack of moisture in the air during the peak of summer. The abundance of sunlight supports the extended daylight hours throughout July, increasing outdoor activity hours. Weather in July »Weather in August
August contends with July for the hottest month in Riverside, California as temperatures rove around the 90s°F. Despite the soaring temperatures, the rainfall continues to remain on the lower end. Sunshine hours remain lengthened, courtesy of the summer. Weather in August »Weather in September
Riverside, California beings to mark the end of summer with a decline in maximum average temperatures in September. However, rainfall remains barely noticeable with a mere 0.08" (2mm) recorded. The wind conditions mirror those from previous months, upholding the calm suave. Weather in September »Weather in October
In October, the transition from summer to fall continues, reflected by a significant decrease in mean temperature. There is also a marked increase in precipitation with rainfall accumulating to 0.2" (5mm). However, despite the onset of fall, the abundance of sunshine and daylight continues to grace Riverside. Weather in October »Weather in November
November in Riverside, California witnesses further decrease in average temperatures. Rainfall escalates up to 0.75" (19mm), ushering in the city's wet season. The daylight duration reduces, indicative of winter's swift approach. Weather in November »Weather in December
As Riverside revels in the holiday season the weather turns chillier with December marking the onset of winter in the city. Rainfall hits a significant rise, accumulating 1.61" (41mm) through the month. Sporadic cloud cover blankets the cityscape, setting December’s distinctive ambience. Weather in December »Updated: Feb 9, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
In Riverside, California, during the entire year, the rain falls for 49 days and collects up to 7.32" (186mm) of precipitation.
In Riverside, snow does not fall in January, March through December.
In Riverside, during the entire year, snow falls for 0.1 days.
The wettest months are February and December, with an average 1.61" (41mm) of rainfall.
February is the only month when snow falls in Riverside.
February has the most snowfall days of the year in Riverside, California. Snow falls for 0.1 days.
The months with the least sunshine are February and December, with an average of 6.8h of sunshine.
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts in Riverside, and the time zone changes from PST to PDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from PDT to PST.
May is the most humid month in Riverside, California, with an average relative humidity of 56%.
June is the month with the least rainfall in Riverside, California. Rain falls for 1.1 days and accumulates 0.04" (1mm) of precipitation.
June has the longest days of the year in Riverside, with an average of 14h and 24min of daylight.
The months with the most sunshine are July and August, with an average of 12.1h of sunshine.
The months with the highest UV index in Riverside are July and August, with an average maximum UV index of 7.
August proves to be the warmest month, recording an average peak temperature of 91.2°F (32.9°C) and a minimum temperature of 66.4°F (19.1°C).
With an average relative humidity of 43%, August is the least humid month in Riverside, California.
December is the coldest month of the year, registering average temperatures as high as 63.3°F (17.4°C) and as low as 45.9°F (7.7°C).
December has the shortest days of the year in Riverside, California, with an average of 9h and 54min of daylight.
December is the month with the lowest UV index in Riverside, with an average maximum UV index of 3.
Average temperature
Riverside, CA
The warmest month (with the highest average high temperature) is August (91.2°F).
The month with the lowest average high temperature is December (63.3°F).
The month with the highest average low temperature is August (66.4°F).
The coldest month (with the lowest average low temperature) is December (45.9°F).
Average pressure
Riverside, CA
- Average pressure in January:
30.1"Hg - Average pressure in February:
30.04"Hg - Average pressure in March:
30.01"Hg - Average pressure in April:
29.95"Hg - Average pressure in May:
29.9"Hg - Average pressure in June:
29.86"Hg
- Average pressure in July:
29.89"Hg - Average pressure in August:
29.88"Hg - Average pressure in September:
29.88"Hg - Average pressure in October:
29.94"Hg - Average pressure in November:
30.03"Hg - Average pressure in December:
30.07"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.86"Hg).
Average wind speed
Riverside, CA
- Average wind speed in January:
5.2mph - Average wind speed in February:
4.9mph - Average wind speed in March:
5mph - Average wind speed in April:
5.5mph - Average wind speed in May:
5.6mph - Average wind speed in June:
5.3mph
- Average wind speed in July:
5mph - Average wind speed in August:
4.7mph - Average wind speed in September:
4.4mph - Average wind speed in October:
4.7mph - Average wind speed in November:
4.8mph - Average wind speed in December:
5mph
The windiest month (with the highest average wind speed) is May (5.6mph).
The calmest month (with the lowest average wind speed) is September (4.4mph).
Average humidity
Riverside, CA
The month with the highest relative humidity is May (56%).
The month with the lowest relative humidity is August (43%).
Average rainfall
Riverside, CA
- Average rainfall in January:
1.1" - Average rainfall in February:
1.61" - Average rainfall in March:
0.87" - Average rainfall in April:
0.63" - Average rainfall in May:
0.2" - Average rainfall in June:
0.04"
- Average rainfall in July:
0.16" - Average rainfall in August:
0.08" - Average rainfall in September:
0.08" - Average rainfall in October:
0.2" - Average rainfall in November:
0.75" - Average rainfall in December:
1.61"
The wettest months (with the highest rainfall) are February and December (1.61").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days
Riverside, CA
- Average rainfall days in January:
5.2 days - Average rainfall days in February:
5.8 days - Average rainfall days in March:
7.7 days - Average rainfall days in April:
5.8 days - Average rainfall days in May:
4.4 days - Average rainfall days in June:
1.1 days
- Average rainfall days in July:
3.1 days - Average rainfall days in August:
1.7 days - Average rainfall days in September:
2.1 days - Average rainfall days in October:
2.6 days - Average rainfall days in November:
3.7 days - Average rainfall days in December:
5.8 days
The month with the highest number of rainy days is March (7.7 days).
The month with the least rainy days is June (1.1 days).
Average snowfall days
Riverside, CA
- Average snowfall days in January:
0 days - Average snowfall days in February:
0.1 days - Average snowfall days in March:
0 days - Average snowfall days in April:
0 days - Average snowfall days in May:
0 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
0 days - Average snowfall days in November:
0 days - Average snowfall days in December:
0 days
The month with the highest number of snowfall days is February (0.1 days).
The months with the least snowfall days are January, March, April, May, June, July, August, September, October, November and December (0 days).
Average daylight / Average sunshine
Riverside, CA
- Average daylight in January:
10h and 12min - Average daylight in February:
11h and 0min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 6min - Average daylight in May:
13h and 54min - Average daylight in June:
14h and 24min
- Average daylight in July:
14h and 12min - Average daylight in August:
13h and 24min - Average daylight in September:
12h and 24min - Average daylight in October:
11h and 18min - Average daylight in November:
10h and 24min - Average daylight in December:
9h and 54min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in January:
6h and 54min - Average sunshine in February:
6h and 48min - Average sunshine in March:
8h and 42min - Average sunshine in April:
11h and 0min - Average sunshine in May:
11h and 18min - Average sunshine in June:
12h and 0min
- Average sunshine in July:
12h and 6min - Average sunshine in August:
12h and 6min - Average sunshine in September:
10h and 36min - Average sunshine in October:
8h and 48min - Average sunshine in November:
7h and 12min - Average sunshine in December:
6h and 48min
The months with the most sunshine are July and August (Average sunshine: 12h and 6min).
The months with the least sunshine are February and December (Average sunshine: 6h and 48min).
Average sunshine days
Riverside, CA
- Average sunshine days in January:
25 days - Average sunshine days in February:
21.6 days - Average sunshine days in March:
23.3 days - Average sunshine days in April:
23.6 days - Average sunshine days in May:
24.9 days - Average sunshine days in June:
27.9 days
- Average sunshine days in July:
25.2 days - Average sunshine days in August:
26.9 days - Average sunshine days in September:
25.8 days - Average sunshine days in October:
26.3 days - Average sunshine days in November:
25.3 days - Average sunshine days in December:
23.8 days
The month with the most sunshine days is June (27.9 days).
The month with the least sunshine days is February (21.6 days).
Average UV index
Riverside, CA
The months with the highest UV index are July and August (UV index 7).
The month with the lowest UV index is December (UV index 3).
Average cloud cover
Riverside, CA
The months with the most cloud cover are February and March (Cloud cover 23).
The month with the least cloud cover is August (Cloud cover 5).
Average visibility
Riverside, CA
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
