Monthly weather forecast and climate
Rialto, CA

Weather in January

January is a comfortable winter month in Rialto, California, with average temperature fluctuating between 44.2°F (6.8°C) and 62.4°F (16.9°C). In January, the average high-temperature is relatively the same as in December - an enjoyable 62.4°F (16.9°C). Weather in January »

Weather in February

February, the last month of the winter, in Rialto, is also an enjoyable month, with average temperature fluctuating between 43.3°F (6.3°C) and 62.4°F (16.9°C). In February, the average high-temperature remains the same as in January - a still comfortable 62.4°F (16.9°C). Weather in February »

Weather in March

March, the first month of the spring, in Rialto, is also an enjoyable month, with temperature in the range of an average high of 66.9°F (19.4°C) and an average low of 45.3°F (7.4°C). In Rialto, the average high-temperature is practically the same as in February - a still enjoyable 66.9°F (19.4°C). Weather in March »

Weather in April

April in Rialto, California, is a pleasant spring month, with average temperature ranging between max 71.8°F (22.1°C) and min 48.2°F (9°C). In Rialto, the average high-temperature in April is almost the same as in March - an agreeable 71.8°F (22.1°C). Weather in April »

Weather in May

The last month of the spring, May, is a moderately hot month in Rialto, California, with average temperature ranging between max 76.6°F (24.8°C) and min 52.3°F (11.3°C). In May, the average high-temperature is relatively the same as in April - a warm 76.6°F (24.8°C). Weather in May »

Weather in June

June, the first month of the summer, in Rialto, is also a moderately hot month, with average temperature varying between 85.5°F (29.7°C) and 57.7°F (14.3°C). In Rialto, the average high-temperature slightly increases, from a warm 76.6°F (24.8°C) in May, to a still moderately hot 85.5°F (29.7°C). Weather in June »

Weather in July

July is a hot summer month in Rialto, California, with average temperature varying between 64.2°F (17.9°C) and 91.2°F (32.9°C). In July, the average high-temperature slightly increases, from a moderately hot 85.5°F (29.7°C) in June, to a tropical 91.2°F (32.9°C). Weather in July »

Weather in August

The last month of the summer, August, is another tropical month in Rialto, California, with average temperature varying between 65.8°F (18.8°C) and 91.9°F (33.3°C). With an average high-temperature of 91.9°F (33.3°C) and an average low-temperature of 65.8°F (18.8°C), August is the warmest month. Weather in August »

Weather in September

The first month of the autumn, September, is also a hot month in Rialto, California, with average temperature ranging between max 87.8°F (31°C) and min 63°F (17.2°C). In Rialto, the average high-temperature in September is almost the same as in August - a still hot 87.8°F (31°C). Weather in September »

Weather in October

October, like September, in Rialto, California, is another warm autumn month, with temperature in the range of an average low of 56.1°F (13.4°C) and an average high of 77.9°F (25.5°C). In Rialto, the average high-temperature in October drops, from a tropical 87.8°F (31°C) in September, to a moderately hot 77.9°F (25.5°C). Weather in October »

Weather in November

November, the last month of the autumn, in Rialto, is also an agreeable month, with temperature in the range of an average high of 68.9°F (20.5°C) and an average low of 49.1°F (9.5°C). In Rialto, California, the average high-temperature in November decreases, from a moderately hot 77.9°F (25.5°C) in October, to a pleasant 68.9°F (20.5°C). Weather in November »

Weather in December

December, the first month of the winter, in Rialto, is still a mild month, with average temperature ranging between max 59.9°F (15.5°C) and min 43.5°F (6.4°C). With an average high-temperature of 59.9°F (15.5°C) and an average low-temperature of 43.5°F (6.4°C), December is the coldest month. Weather in December »
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FAQ

How many days does it rain in Rialto?

Throughout the year, in Rialto, there are 43.5 rainfall days, and 5.43" (138mm) of precipitation is accumulated.

How many days does it snow in Rialto?

In Rialto, during the entire year, snow falls for 0.1 days.

When it does not snow in Rialto?

January, March through December are months without snowfall.

What is the most humid month in Rialto?

February and March, with an average relative humidity of 52%, are most humid months in Rialto.

What is the wettest month in Rialto?

Months with the most rainfall in Rialto, California, are February and December, with an average 1.14" (29mm) of precipitation.

When does it snow in Rialto?

The only month with snowfall in Rialto is February.

When does it snow the most in Rialto?

The month with the most snowfall days is February when snow falls for 0.1 days.

What is the driest month in Rialto?

June is the month with the least rainfall. Rain falls for 1.3 days and accumulates 0.04" (1mm) of precipitation.

When are the longest days in Rialto?

The month with the longest days in Rialto, California, is June, with an average of 14.4h of daylight.

What are the months with the most sunshine in Rialto?

June and July, with an average of 12.1h of sunshine, are months with the most sunshine in Rialto.

What is the month with the highest UV index in Rialto?

Months with the highest UV index are June through August, with an average maximum UV index of 7.

What is the warmest month in Rialto?

August is the warmest month in Rialto, with an average high-temperature of 91.9°F (33.3°C) and an average low-temperature of 65.8°F (18.8°C).

What is the least humid month in Rialto?

With an average relative humidity of 38%, August is the least humid month.

What is the coldest month in Rialto?

With an average high-temperature of 59.9°F (15.5°C) and an average low-temperature of 43.5°F (6.4°C), December is the coldest month.

What is the month with the shortest days in Rialto?

With an average of 9.9h of daylight, December has the shortest days of the year in Rialto.

What is the month with the least sunshine in Rialto?

December has the least sunshine of the year, with an average of 6.9h of sunshine.

When is the lowest UV index in Rialto?

With an average maximum UV index of 3, December is the month with the lowest UV index.

Average temperature
Rialto, CA

Average temperature - Rialto, CA

The warmest month (with the highest average high temperature) is August (91.9°F).
The month with the lowest average high temperature is December (59.9°F).

The month with the highest average low temperature is August (65.8°F).
The coldest month (with the lowest average low temperature) is February (43.3°F).

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Average pressure
Rialto, CA

Average pressure - Rialto, CA

The month with the highest atmospheric pressure is January (30.1").
The month with the lowest atmospheric pressure is June (29.85").

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Average wind speed
Rialto, CA

Average wind speed - Rialto, CA

The windiest month (with the highest average wind speed) is April (6.2mph).
The calmest month (with the lowest average wind speed) is September (4.5mph).

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Average humidity
Rialto, CA

Average humidity - Rialto, CA

Months with the highest relative humidity are February and March (52%).
The month with the lowest relative humidity is August (38%).

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Average rainfall
Rialto, CA

Average rainfall - Rialto, CA

The wettest months (with the highest rainfall) are February and December (1.14").
The driest month (with the least rainfall) is June (0.04").

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Average rainfall days
Rialto, CA

Average rainfall days - Rialto, CA

The month with the highest number of rainy days is December (5.5 days).
The month with the least rainy days is June (1.3 days).

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Average snowfall days
Rialto, CA

Average snowfall days - Rialto, CA

The month with the highest number of snowfall days is February (0.1 days).
Months with the least snowfall days are January, March, April, May, June, July, August, September, October, November and December (0 days).

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Average daylight / Average sunshine
Rialto, CA

Average daylight / Average sunshine - Rialto, CA

The month with the longest days is June (Average daylight: 14.4h).
The month with the shortest days is December (Average daylight: 9.9h).

Months with the most sunshine are June and July (Average sunshine: 12.1h).
The month with the least sunshine is December (Average sunshine: 6.9h).

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Average sunshine days
Rialto, CA

Average sunshine days - Rialto, CA

The month with the most sunshine days is June (27.8 days).
The month with the least sunshine days is February (22.6 days).

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Average visibility
Rialto, CA

Average visibility - Rialto, CA

Months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

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