Monthly weather forecast and climate
Portola, CA

Weather in January

January, like December, in Portola, California, is another cold winter month, with temperature in the range of an average low of 23.2°F (-4.9°C) and an average high of 38.8°F (3.8°C). In January, the average high-temperature is relatively the same as in December - a still wintry 38.8°F (3.8°C). Weather in January »

Weather in February

The last month of the winter, February, is another cold month in Portola, California, with temperature in the range of an average high of 39.6°F (4.2°C) and an average low of 22.8°F (-5.1°C). In February, the average high-temperature is essentially the same as in January - a still wintry 39.6°F (4.2°C). Weather in February »

Weather in March

The first month of the spring, March, is a chilly month in Portola, California, with temperature in the range of an average low of 25.3°F (-3.7°C) and an average high of 43.2°F (6.2°C). In March, the average high-temperature is relatively the same as in February - a chilly 43.2°F (6.2°C). Weather in March »

Weather in April

April is a cool spring month in Portola, California, with average temperature ranging between min 29.7°F (-1.3°C) and max 51.4°F (10.8°C). In April, the average high-temperature slightly increases, from a chilly 43.2°F (6.2°C) in March, to a fresh 51.4°F (10.8°C). Weather in April »

Weather in May

The last month of the spring, May, is a mild month in Portola, California, with average temperature ranging between max 60.6°F (15.9°C) and min 35.8°F (2.1°C). In Portola, the average high-temperature increases, from a cool 51.4°F (10.8°C) in April, to a mild 60.6°F (15.9°C). Weather in May »

Weather in June

The first month of the summer, June, is a pleasant month in Portola, California, with average temperature fluctuating between 72.7°F (22.6°C) and 42.1°F (5.6°C). In June, the average high-temperature increases, from a mild 60.6°F (15.9°C) in May, to an agreeable 72.7°F (22.6°C). Weather in June »

Weather in July

July in Portola, California, is a moderately hot summer month, with average temperature varying between 47.5°F (8.6°C) and 82.9°F (28.3°C). July is the warmest month, with an average high-temperature of 82.9°F (28.3°C) and an average low-temperature of 47.5°F (8.6°C). The average heat index in July is estimated at 82.2°F (27.9°C). Weather in July »

Weather in August

The last month of the summer, August, is also a moderately hot month in Portola, California, with average temperature ranging between min 46°F (7.8°C) and max 81.1°F (27.3°C). In Portola, the average high-temperature is essentially the same as in July - a still moderately hot 81.1°F (27.3°C). Weather in August »

Weather in September

The first month of the autumn, September, is also a moderately hot month in Portola, California, with average temperature fluctuating between 42.3°F (5.7°C) and 73.8°F (23.2°C). In September, the average high-temperature marginally drops, from a warm 81.1°F (27.3°C) in August, to a still moderately hot 73.8°F (23.2°C). Weather in September »

Weather in October

October, the same as September, in Portola, California, is another mild autumn month, with temperature in the range of an average high of 60.4°F (15.8°C) and an average low of 34.9°F (1.6°C). In Portola, the average high-temperature in October drops, from a moderately hot 73.8°F (23.2°C) in September, to a moderate 60.4°F (15.8°C). Weather in October »

Weather in November

November, the last month of the autumn, in Portola, is another chilly month, with average temperature varying between 47.3°F (8.5°C) and 27°F (-2.8°C). In Portola, the average high-temperature decreases, from a mild 60.4°F (15.8°C) in October, to a frosty 47.3°F (8.5°C). Weather in November »

Weather in December

The first month of the winter, December, is still a cold month in Portola, California, with average temperature fluctuating between 37.2°F (2.9°C) and 21.6°F (-5.8°C). December is the coldest month, with an average high-temperature of 37.2°F (2.9°C) and an average low-temperature of 21.6°F (-5.8°C). Weather in December »
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FAQ

What are the most humid months in Portola?

January and March, with an average relative humidity of 81%, are most humid months in Portola.

How much does it rain in Portola?

In Portola, California, during the entire year, the rain falls for 80.1 days and collects up to 22.95" (583mm) of precipitation.

When does it snow in Portola?

Months with snowfall are January through June, September through December.

How many days does it snow in Portola?

In Portola, California, during the entire year, snow falls for 69.3 days, and aggregates up to 103.5" (2629mm) of snow.

What is the month with the least sunshine in Portola?

With an average of 5h of sunshine, January has the least sunshine of the year in Portola.

What is the wettest month in Portola?

March is the month with the most rainfall in Portola. Rain falls for 10.1 days and accumulates 4.02" (102mm) of precipitation.

When are the longest days in Portola?

June has the longest days of the year, with an average of 15h of daylight.

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

June through August, with an average maximum UV index of 5, are months with the highest UV index in Portola.

What is the warmest month in Portola?

The warmest month is July, with an average high-temperature of 82.9°F (28.3°C) and an average low-temperature of 47.5°F (8.6°C).

What is the least humid month in Portola?

July and August, with an average relative humidity of 40%, are the least humid months.

When it does not snow in Portola?

July and August are months without snowfall.

What month has the most sunshine in Portola?

July has the most sunshine of the year, with an average of 12h of sunshine.

What is the driest month in Portola?

The month with the least rainfall in Portola is August when the rain falls for 3.4 days and typically collects 0.2" (5mm) of precipitation.

When is the lowest UV index in Portola?

November is the month with the lowest UV index, with an average maximum UV index of 1.

What is the coldest month in Portola?

December is the coldest month in Portola, with an average high-temperature of 37.2°F (2.9°C) and an average low-temperature of 21.6°F (-5.8°C).

What is the snowiest month in Portola?

December is the month with the most snowfall in Portola, California. Snow falls for 12.8 days and accumulates 22.52" (572mm) of snow.

What is the month with the shortest days in Portola?

With an average of 9.4h of daylight, December has the shortest days of the year in Portola, California.

Average temperature
Portola, CA

Average temperature - Portola, CA

The warmest month (with the highest average high temperature) is July (82.9°F).
The month with the lowest average high temperature is December (37.2°F).

The month with the highest average low temperature is July (47.5°F).
The coldest month (with the lowest average low temperature) is December (21.6°F).

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Average pressure
Portola, CA

Average pressure - Portola, CA

The month with the highest atmospheric pressure is January (30.19").
The month with the lowest atmospheric pressure is June (29.9").

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Average wind speed
Portola, CA

Average wind speed - Portola, CA

The windiest month (with the highest average wind speed) is March (6.6mph).
The calmest months (with the lowest average wind speed) are August and September (5.2mph).

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Average humidity
Portola, CA

Average humidity - Portola, CA

Months with the highest relative humidity are January and March (81%).
Months with the lowest relative humidity are July and August (40%).

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Average rainfall
Portola, CA

Average rainfall - Portola, CA

The wettest month (with the highest rainfall) is March (4.02").
The driest month (with the least rainfall) is August (0.2").

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Average rainfall days
Portola, CA

Average rainfall days - Portola, CA

The month with the highest number of rainy days is May (11.8 days).
The month with the least rainy days is July (3.3 days).

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Average snowfall
Portola, CA

Average snowfall - Portola, CA

The month with the highest snowfall is December (22.52").
Months with the least snowfall are July and August (0").

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Average snowfall days
Portola, CA

Average snowfall days - Portola, CA

The month with the highest number of snowfall days is March (14.7 days).
Months with the least snowfall days are July and August (0 days).

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Average daylight / Average sunshine
Portola, CA

Average daylight / Average sunshine - Portola, CA

The month with the longest days is June (Average daylight: 15h).
The month with the shortest days is December (Average daylight: 9.4h).

The month with the most sunshine is July (Average sunshine: 12h).
The month with the least sunshine is January (Average sunshine: 5h).

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Average sunshine days
Portola, CA

Average sunshine days - Portola, CA

The month with the most sunshine days is August (26 days).
The month with the least sunshine days is March (11.8 days).

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Average visibility
Portola, CA

Average visibility - Portola, CA

Months with the highest visibility are May, June, July, August, September, October and November (6mi).
Months with the lowest visibility are January and December (4mi).

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