Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
Portola Hills experiences its lowest temperatures in December, with an average peak of 63.1°F (17.3°C) and a low of 49.5°F (9.7°C).Humidity
In December, the average relative humidity in Portola Hills is 59%.Rainfall
The month with the most rainfall in Portola Hills, California, is December, when the rain falls for 6.7 days and typically aggregates up to 1.85" (47mm) of precipitation.Daylight
The month with the shortest days is December, with an average of 10h and 0min of daylight.On the first day of the month, sunrise is at 6:37 am and sunset at 4:42 pm. On the last day of December, sunrise is at 6:55 am and sunset at 4:52 pm PST.
Sunshine
The month with the least sunshine in Portola Hills is December, with an average of 6.6h of sunshine.UV index
January through March, November and December, with an average maximum UV index of 4, are months with the lowest UV index in Portola Hills, California. A UV Index reading of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for the average person.Note: The UV index of 4 during December translates into the following guidance:
Make use of precautions - Suggestions to resist sunburn are communicated. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation.
Frequently asked questions
What month is the coldest in Portola Hills?
What is the usual temperature for Portola Hills in December?
What is the average humidity in December in Portola Hills?
What is the rainiest month in Portola Hills?
How many days does it rain in December in Portola Hills?
What is the month with the shortest days in Portola Hills?
What is the average length of the day in December in Portola Hills?
What time are sunrise and sunset in December in Portola Hills?
What is the month with the least sunshine in Portola Hills?
How many hours of sunshine does Portola Hills have in December?
When is the lowest UV index in Portola Hills?
What is the UV index intensity in December in Portola Hills?
Average temperature in December
Portola Hills, CA
- Average high temperature in December: 63.1°F
The warmest month (with the highest average high temperature) is August (82°F).
The month with the lowest average high temperature is December (63.1°F).
- Average low temperature in December: 49.5°F
The month with the highest average low temperature is August (64.4°F).
The coldest month (with the lowest average low temperature) is February (48.7°F).
Average pressure in December
Portola Hills, CA
- Average pressure in December: 30.07"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The months with the lowest atmospheric pressure are June and September (29.88"Hg).
Average wind speed in December
Portola Hills, CA
- Average wind speed in December: 5mph
The windiest months (with the highest average wind speed) are April and May (5.7mph).
The calmest months (with the lowest average wind speed) are August and September (4.5mph).
Average humidity in December
Portola Hills, CA
- Average humidity in December: 59%
The months with the highest relative humidity are May and June (69%).
The month with the lowest relative humidity is November (55%).
Average rainfall in December
Portola Hills, CA
- Average rainfall in December: 1.85"
The wettest month (with the highest rainfall) is December (1.85").
The driest month (with the least rainfall) is June (0.08").
Average rainfall days in December
Portola Hills, CA
- Average rainfall days in December: 6.7 days
The month with the highest number of rainy days is March (8.1 days).
The month with the least rainy days is June (2 days).
Average daylight in December /
Average sunshine in December
Portola Hills, CA
- Average daylight in December: 10h and 0min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 10h and 0min).
- Average sunshine in December: 6h and 4min
The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 6h and 36min).
Average sunshine days in December
Portola Hills, CA
- Average sunshine days in December: 22.5 days
The months with the most sunshine days are January and October (24.2 days).
The month with the least sunshine days is May (19.3 days).
Average UV index in December
Portola Hills, CA
- Average UV index in December: 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).
Average cloud cover in December
Portola Hills, CA
- Average cloud cover in December: 24
The months with the most cloud cover are March and December (Cloud cover 24).
The month with the least cloud cover is August (Cloud cover 6).
Average visibility in December
Portola Hills, CA
- Average visibility in December: 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).
Portola Hills, California, USA
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