January weather forecast and climate
Saint Helena, CA

Weather in January

January in Saint Helena, California, is a moderate winter month, with temperature in the range of an average high of 56.8°F (13.8°C) and an average low of 39.7°F (4.3°C).

Temperature

In Saint Helena, the average high-temperature in January is practically the same as in December - a mild 56.8°F (13.8°C). The average low-temperature, in January, is 39.7°F (4.3°C).

Humidity

In Saint Helena, the average relative humidity is 74%.

Rainfall

In January, the rain falls for 10.2 days. Throughout January, 3.15" (80mm) of precipitation is accumulated. In Saint Helena, during the entire year, the rain falls for 76.2 days and collects up to 16.93" (430mm) of precipitation.

Snowfall

January, February, April through December are months without snowfall in Saint Helena.

Daylight

In Saint Helena, the average length of the day is 9.9h.

Sunshine

In Saint Helena, the average sunshine in January is 5.4h.

UV index

Months with the lowest UV index are January, February, November and December, with an average maximum UV index of 3. A UV Index value of 3 to 5 symbolizes a moderate threat to health from the exposure to the Sun's UV radiation for ordinary individuals.
Note: In January, the average maximum UV index of 3 translate into the following recommendations:
Take precautions. Light skin individuals may get burned in less than 30 minutes. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun.
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FAQ

What is the average humidity in January in Saint Helena?

In January, the average relative humidity in Saint Helena, California, is 74%.

How many days does it rain in January in Saint Helena?

In January, in Saint Helena, the rain falls for 10.2 days. Throughout January, 3.15" (80mm) of precipitation is accumulated.

When it does not snow in Saint Helena?

In Saint Helena, California, snow does not fall in January, February, April through December.

How many hours of daylight does Saint Helena have in January?

In January, the average length of the day is 9.9h.

How long on average sun shines in January in Saint Helena?

In January, the average sunshine is 5.4h.

When is the lowest UV index in Saint Helena?

January, February, November and December, with an average maximum UV index of 3, are months with the lowest UV index in Saint Helena.

What is the UV index intensity in January in Saint Helena?

In January, the average daily maximum UV index in Saint Helena is 3. A UV Index estimate of 3 to 5 represents a medium hazard to health from unprotected exposure to the UV radiation.

Average temperature in January
Saint Helena, CA

Average temperature in January - Saint Helena, CA
  • Average high temperature in January: 56.8°F

The warmest month (with the highest average high temperature) is July (88.3°F).
The month with the lowest average high temperature is December (54.5°F).

  • Average low temperature in January: 39.7°F

The month with the highest average low temperature is September (54.3°F).
The coldest month (with the lowest average low temperature) is December (39.6°F).

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Average pressure in January
Saint Helena, CA

Average pressure in January - Saint Helena, CA
  • Average pressure in January: 30.14"

The month with the highest atmospheric pressure is January (30.14").
Months with the lowest atmospheric pressure are June, August and September (29.91").

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Average wind speed in January
Saint Helena, CA

Average wind speed in January - Saint Helena, CA
  • Average wind speed in January: 4.5mph

The windiest month (with the highest average wind speed) is May (5.8mph).
The calmest month (with the lowest average wind speed) is November (4.3mph).

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Average humidity in January
Saint Helena, CA

Average humidity in January - Saint Helena, CA
  • Average humidity in January: 74%

The month with the highest relative humidity is March (76%).
The month with the lowest relative humidity is September (53%).

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Average rainfall in January
Saint Helena, CA

Average rainfall in January - Saint Helena, CA
  • Average rainfall in January: 3.15"

The wettest month (with the highest rainfall) is February (3.7").
The driest month (with the least rainfall) is July (0").

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Average rainfall days in January
Saint Helena, CA

Average rainfall days in January - Saint Helena, CA
  • Average rainfall days in January: 10.2 days

The month with the highest number of rainy days is March (13.5 days).
The month with the least rainy days is August (0.3 days).

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Average snowfall in January
Saint Helena, CA

Average snowfall in January - Saint Helena, CA
  • Average snowfall in January: 0"

The month with the highest snowfall is March (0.04").
Months with the least snowfall are January, February, April, May, June, July, August, September, October, November and December (0").

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Average snowfall days in January
Saint Helena, CA

Average snowfall days in January - Saint Helena, CA
  • Average snowfall days in January: 0 days

The month with the highest number of snowfall days is March (0.2 days).
Months with the least snowfall days are January, February, April, May, June, July, August, September, October, November and December (0 days).

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Average daylight in January /
Average sunshine in January
Saint Helena, CA

Average daylight in January / Average sunshine in January - Saint Helena, CA
  • Average daylight in January: 9.9h

The month with the longest days is June (Average daylight: 14.8h).
The month with the shortest days is December (Average daylight: 9.5h).

  • Average sunshine in January: 5.4h

The month with the most sunshine is July (Average sunshine: 11.9h).
The month with the least sunshine is December (Average sunshine: 5.3h).

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Average sunshine days in January
Saint Helena, CA

Average sunshine days in January - Saint Helena, CA
  • Average sunshine days in January: 19.9 days

The month with the most sunshine days is July (30 days).
The month with the least sunshine days is March (15.9 days).

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Average UV index in January
Saint Helena, CA

Average UV index in January - Saint Helena, CA
  • Average UV index in January: 3

Months with the highest UV index are June, July and August (UV index 6).
Months with the lowest UV index are January, February, November and December (UV index 3).

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Average cloud cover in January
Saint Helena, CA

Average cloud cover in January - Saint Helena, CA
  • Average cloud cover in January: 41

The month with the most cloud cover is March (Cloud cover 44).
The month with the least cloud cover is July (Cloud cover 7).

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Average visibility in January
Saint Helena, CA

Average visibility in January - Saint Helena, CA
  • Average visibility in January: 5mi

Months with the highest visibility are February, April, May, June, July, August, September, October, November and December (6mi).
Months with the lowest visibility are January and March (5mi).

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