December weather forecastPort San Luis, CA
December
Weather in December
December, the first month of the winter in Port San Luis, is also a moderate month, with temperature in the range of an average high of 60.3°F (15.7°C) and an average low of 46.2°F (7.9°C).Temperature
December is the month when Port San Luis experiences its coldest temperatures, averaging a high of 60.3°F (15.7°C) and a low of 46.2°F (7.9°C).Humidity
The average relative humidity in December is 64%.Rainfall
In Port San Luis, in December, during 7.7 rainfall days, 1.46" (37mm) of precipitation is typically accumulated. In Port San Luis, during the entire year, the rain falls for 57 days and collects up to 9.57" (243mm) of precipitation.Daylight
The month with the shortest days is December, with an average of 9h and 48min of daylight.On the first day of December, sunrise is at 6:53 am and sunset at 4:50 pm. On the last day of the month, sunrise is at 7:11 am and sunset at 5:01 pm PST.
Sunshine
The months with the least sunshine are February and December, with an average of 6.5h of sunshine.UV index
In December, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for average individuals.Note: The maximum UV index, 4 during December, leads to the following recommendations:
Undertake protective steps - Preventing sun damage is advised. Limiting sun exposure during midday hours helps in reducing the harmful effects of UV radiation. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Port San Luis, CA
- Average high temperature in December: 60.3°F
The warmest month (with the highest average high temperature) is August (80.2°F).
The month with the lowest average high temperature is December (60.3°F).
- Average low temperature in December: 46.2°F
The month with the highest average low temperature is September (60.3°F).
The coldest month (with the lowest average low temperature) is February (45.7°F).
Average pressure in December
Port San Luis, CA
- Average pressure in December: 30.09"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.91"Hg).
Average wind speed in December
Port San Luis, CA
- Average wind speed in December: 6.2mph
The windiest months (with the highest average wind speed) are April and May (6.8mph).
The calmest months (with the lowest average wind speed) are August and September (5.3mph).
Average humidity in December
Port San Luis, CA
- Average humidity in December: 64%
The month with the highest relative humidity is March (69%).
The months with the lowest relative humidity are September and October (57%).
Average rainfall in December
Port San Luis, CA
- Average rainfall in December: 1.46"
The wettest month (with the highest rainfall) is March (2.01").
The driest months (with the least rainfall) are June and August (0.04").
Average rainfall days in December
Port San Luis, CA
- Average rainfall days in December: 7.7 days
The month with the highest number of rainy days is March (10.5 days).
The month with the least rainy days is August (0.6 days).
Average daylight in December /
Average sunshine in December
Port San Luis, CA
- Average daylight in December: 9h and 48min
The month with the longest days is June (Average daylight: 14h and 30min).
The month with the shortest days is December (Average daylight: 9h and 48min).
- Average sunshine in December: 6h and 30min
The months with the most sunshine are June, July and August (Average sunshine: 12h and 0min).
The months with the least sunshine are February and December (Average sunshine: 6h and 30min).
Average sunshine days in December
Port San Luis, CA
- Average sunshine days in December: 22.2 days
The month with the most sunshine days is August (29.2 days).
The month with the least sunshine days is February (19.1 days).
Average UV index in December
Port San Luis, CA
- Average UV index in December: 4
The months with the highest UV index are June and August (UV index 6).
The month with the lowest UV index is February (UV index 3).
Average cloud cover in December
Port San Luis, CA
- Average cloud cover in December: 25
The month with the most cloud cover is March (Cloud cover 28).
The months with the least cloud cover are August and September (Cloud cover 6).
Average visibility in December
Port San Luis, 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).
