January weather forecast
San Marcos, CA

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Weather in January

January, like December, in San Marcos, California, is another refreshing winter month, with an average temperature varying between 64.9°F (18.3°C) and 48.7°F (9.3°C).

Temperature

January's presence records an average high-temperature of a still refreshing 64.9°F (18.3°C), closely mirroring December's climate. The nights of January anticipate an average low-temperature of 48.7°F (9.3°C).

Humidity

In January, the average relative humidity in San Marcos is 58%.

Rainfall

In January, in San Marcos, the rain falls for 5 days. Throughout January, 0.59" (15mm) of precipitation is accumulated. In San Marcos, during the entire year, the rain falls for 52.1 days and collects up to 6.1" (155mm) of precipitation.

Daylight

In San Marcos, the average length of the day in January is 10h and 16min.
On the first day of January in San Marcos, sunrise is at 6:51 am and sunset at 4:52 pm. On the last day of the month, sunrise is at 6:44 am and sunset at 5:19 pm PST.

Sunshine

In January, the average sunshine is 6.9h.

UV index

January through March, November and December, with an average maximum UV index of 4, are months with the lowest UV index. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV radiation for average individuals.
Note: A daily high UV index of 4 in January leads to these guidelines:
Adopt protective measures - It is advised to guard against sun damage. Avoiding the Sun's peak radiation during midday hours is essential for health and safety. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat.
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Frequently asked questions

What is the temperature in January in San Marcos?

San Marcos in January has an average high-temperature of 64.9°F (18.3°C) and an average low-temperature of 48.7°F (9.3°C).

What is the average humidity in January in San Marcos?

In San Marcos, the average relative humidity in January is 58%.

How many days does it rain in January in San Marcos?

In San Marcos, California, in January, it is raining for 5 days, with typically 0.59" (15mm) of accumulated precipitation.

How many hours of daylight does San Marcos have in January?

In San Marcos, California, the average day length in January is 10h and 16min.

When is the sunrise / sunset in January in San Marcos?

In January, on the first day of the month, sunrise is at 6:51 am and sunset at 4:52 pm. On the last day of the month, sunrise is at 6:44 am and sunset at 5:19 pm PST.

How long on average sun shines in January in San Marcos?

In January, the average sunshine duration is 6.9h.

When is the lowest UV index in San Marcos?

January through March, November and December, with an average maximum UV index of 4, are months with the lowest UV index in San Marcos.

What is the UV index intensity in January in San Marcos?

The average daily maximum UV index in January in San Marcos is 4. A UV Index value of 3 to 5 symbolizes a moderate vulnerability from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in January
San Marcos, CA

Average temperature in January - San Marcos, CA
  • Average high temperature in January: 64.9°F

The warmest month (with the highest average high temperature) is August (81.9°F).
The months with the lowest average high temperature are February and December (63.3°F).

  • Average low temperature in January: 48.7°F

The month with the highest average low temperature is August (64.2°F).
The coldest month (with the lowest average low temperature) is February (48°F).

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Average pressure in January
San Marcos, CA

Average pressure in January - San Marcos, CA
  • Average pressure in January: 30.09"Hg

The month with the highest atmospheric pressure is January (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).

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Average wind speed in January
San Marcos, CA

Average wind speed in January - San Marcos, CA
  • Average wind speed in January: 5mph

The windiest month (with the highest average wind speed) is April (5.7mph).
The calmest month (with the lowest average wind speed) is October (4.4mph).

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Average humidity in January
San Marcos, CA

Average humidity in January - San Marcos, CA
  • Average humidity in January: 58%

The month with the highest relative humidity is May (70%).
The month with the lowest relative humidity is November (56%).

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Average rainfall in January
San Marcos, CA

Average rainfall in January - San Marcos, CA
  • Average rainfall in January: 0.59"

The wettest month (with the highest rainfall) is December (1.22").
The driest month (with the least rainfall) is June (0.08").

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Average rainfall days in January
San Marcos, CA

Average rainfall days in January - San Marcos, CA
  • Average rainfall days in January: 5 days

The month with the highest number of rainy days is March (7.8 days).
The month with the least rainy days is June (1.2 days).

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Average daylight in January /
Average sunshine in January
San Marcos, CA

Average daylight in January / Average sunshine in January - San Marcos, CA
  • Average daylight in January: 10h and 2min

The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 0min).

  • Average sunshine in January: 6h and 5min

The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 48min).

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Average sunshine days in January
San Marcos, CA

Average sunshine days in January - San Marcos, CA
  • Average sunshine days in January: 25 days

The month with the most sunshine days is August (25.8 days).
The month with the least sunshine days is February (20 days).

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Average UV index in January
San Marcos, CA

Average UV index in January - San Marcos, CA
  • Average UV index in January: 4

The months with the highest UV index are June, July, August and September (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 4).

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Average cloud cover in January
San Marcos, CA

Average cloud cover in January - San Marcos, CA
  • Average cloud cover in January: 20

The months with the most cloud cover are March and December (Cloud cover 23).
The month with the least cloud cover is August (Cloud cover 7).

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Average visibility in January
San Marcos, CA

Average visibility in January - San Marcos, 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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San Marcos, California, USA

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