January weather forecast
Rialto, CA

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Weather in January

January in Rialto, California, is an enjoyable winter month, with an average temperature ranging between min 44.2°F (6.8°C) and max 62.4°F (16.9°C).

Temperature

As Rialto, California, welcomes January, the average high-temperature stabilizes at a comfortable 62.4°F (16.9°C), showing little deviation from December's 59.9°F (15.5°C). January nights experience a consistent temperature drop to a chilly 44.2°F (6.8°C).

Humidity

In Rialto, California, the average relative humidity in January is 48%.

Rainfall

In Rialto, in January, it is raining for 4.8 days, with typically 0.59" (15mm) of accumulated precipitation. In Rialto, during the entire year, the rain falls for 43.5 days and collects up to 5.43" (138mm) of precipitation.

Snowfall

In Rialto, snow does not fall in January, March through December.

Daylight

The average length of the day in January in Rialto, California, is 10h and 11min.
On the first day of the month, sunrise is at 6:55 am and sunset at 4:50 pm. On the last day of January, sunrise is at 6:47 am and sunset at 5:18 pm PST.

Sunshine

In Rialto, the average sunshine in January is 7.1h.

UV index

In Rialto, the average daily maximum UV index in January is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for the average person.
Note: A maximum daily UV index of 4 during January morphs into the following directions:
Ensure safety - Recommendations to avert sunburn are presented. Around midday, solar radiation is most harmful; hence, exposure should be limited. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear.
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Frequently asked questions

What is the average January temperature in Rialto?

The average high-temperature and low-temperature in Rialto during January are 62.4°F (16.9°C) and 44.2°F (6.8°C) respectively.

What is the average humidity in January in Rialto?

The average relative humidity in January in Rialto is 48%.

How much does it rain in Rialto in January?

In January, in Rialto, the rain falls for 4.8 days. Throughout January, 0.59" (15mm) of precipitation is accumulated.

When it does not snow in Rialto?

In Rialto, snow does not fall in January, March through December.

Does it snow in Rialto in January?

In Rialto, California, in January, it doesn't snow. In February, it regularly snows.

What is the average length of the day in January in Rialto?

In Rialto, the average day length in January is 10h and 11min.

When is the sunrise / sunset in January in Rialto?

In January, on the first day of the month, sunrise is at 6:55 am and sunset at 4:50 pm. On the last day of the month, in Rialto, California, sunrise is at 6:47 am and sunset at 5:18 pm PST.

How many hours of sunshine does Rialto have in January?

The average sunshine duration in January is 7.1h.

What is the UV index reading in January in Rialto?

In Rialto, California, the average daily maximum UV index in January is 4. A UV Index of 3 to 5 symbolizes a moderate vulnerability from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in January
Rialto, CA

Average temperature in January - Rialto, CA
  • Average high temperature in January: 62.4°F

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).

  • Average low temperature in January: 44.2°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 in January
Rialto, CA

Average pressure in January - Rialto, CA
  • Average pressure in January: 30.1"Hg

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

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Average wind speed in January
Rialto, CA

Average wind speed in January - Rialto, CA
  • Average wind speed in January: 5.4mph

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 in January
Rialto, CA

Average humidity in January - Rialto, CA
  • Average humidity in January: 48%

The 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 in January
Rialto, CA

Average rainfall in January - Rialto, CA
  • Average rainfall in January: 0.59"

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 in January
Rialto, CA

Average rainfall days in January - Rialto, CA
  • Average rainfall days in January: 4.8 days

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 in January
Rialto, CA

Average snowfall days in January - Rialto, CA
  • Average snowfall days in January: 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).

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Average daylight in January /
Average sunshine in January
Rialto, CA

Average daylight in January / Average sunshine in January - Rialto, CA
  • Average daylight in January: 10h and 1min

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: 7h and 1min

The months with the most sunshine are June and July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 54min).

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Average sunshine days in January
Rialto, CA

Average sunshine days in January - Rialto, CA
  • Average sunshine days in January: 25.1 days

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 UV index in January
Rialto, CA

Average UV index in January - Rialto, CA
  • Average UV index in January: 4

The months with the highest UV index are June, July and August (UV index 7).
The month with the lowest UV index is December (UV index 3).

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Average cloud cover in January
Rialto, CA

Average cloud cover in January - Rialto, CA
  • Average cloud cover in January: 19

The month with the most cloud cover is December (Cloud cover 21).
The month with the least cloud cover is August (Cloud cover 5).

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Average visibility in January
Rialto, CA

Average visibility in January - Rialto, CA
  • Average visibility in January: 6mi

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).

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Rialto, California, USA

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