December weather forecastPasadena, CA
December
Weather in December
Pasadena, California, welcomes winter in December with temperatures dropping to an average low of 46.8°F (8.2°C). The brisk chill in the air indicates the onset of the holiday season and closes off the year on a cooler note. Cloud coverage increases and pace of wind takes an upward trajectory, contributing to a more wintery feel. Despite the cooler temperatures, December remains a popular time for visiting Pasadena, thanks to the festive atmosphere enveloping the city. The chillier nights and shorter days make for cozy evenings while the minimal rainfall keeps the exploring spirit alive.Temperature
December, with its average high-temperature of 61.7°F (16.5°C) and an average low-temperature of 46.8°F (8.2°C), holds the record as the coldest month.Humidity
In Pasadena, the average relative humidity in December is 52%.Rainfall
In December, in Pasadena, the rain falls for 6.1 days. Throughout December, 1.65" (42mm) of precipitation is accumulated. Throughout the year, there are 50.1 rainfall days, and 8.5" (216mm) of precipitation is accumulated.Daylight
The month with the shortest days in Pasadena is December, with an average of 9h and 54min of daylight.On the first day of December, sunrise is at 6:40 am and sunset at 4:43 pm. On the last day of the month, sunrise is at 6:58 am and sunset at 4:53 pm PST.
Sunshine
The months with the least sunshine are January, February and December, with an average of 6.9h of sunshine.UV index
The month with the lowest UV index is December, with an average maximum UV index of 3. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for average individuals.Note: A maximum daily UV index of 3 during December morphs into the following directions:
Exercise prevention - Protecting skin and eyes from harm is required. Given the potency of the midday Sun's UV radiation, one should avoid prolonged exposure. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Pasadena, CA
- Average high temperature in December: 61.7°F
The warmest month (with the highest average high temperature) is August (87.1°F).
The month with the lowest average high temperature is December (61.7°F).
- Average low temperature in December: 46.8°F
The month with the highest average low temperature is August (64.9°F).
The coldest month (with the lowest average low temperature) is February (46.6°F).
Average pressure in December
Pasadena, CA
- Average pressure in December: 30.08"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in December
Pasadena, CA
- Average wind speed in December: 5.2mph
The windiest month (with the highest average wind speed) is April (5.8mph).
The calmest month (with the lowest average wind speed) is September (4.4mph).
Average humidity in December
Pasadena, CA
- Average humidity in December: 52%
The month with the highest relative humidity is June (58%).
The month with the lowest relative humidity is November (47%).
Average rainfall in December
Pasadena, CA
- Average rainfall in December: 1.65"
The wettest month (with the highest rainfall) is February (1.77").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in December
Pasadena, CA
- Average rainfall days in December: 6.1 days
The month with the highest number of rainy days is March (7.8 days).
The month with the least rainy days is June (1.1 days).
Average daylight in December /
Average sunshine in December
Pasadena, CA
- Average daylight in December: 9h and 54min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in December: 6h and 54min
The months with the most sunshine are June and July (Average sunshine: 12h and 6min).
The months with the least sunshine are January, February and December (Average sunshine: 6h and 54min).
Average sunshine days in December
Pasadena, CA
- Average sunshine days in December: 23.4 days
The month with the most sunshine days is June (27.5 days).
The month with the least sunshine days is February (21.5 days).
Average UV index in December
Pasadena, CA
- Average UV index in December: 3
The months with the highest UV index are June, July, August and September (UV index 6).
The month with the lowest UV index is December (UV index 3).
Average cloud cover in December
Pasadena, CA
- Average cloud cover in December: 21
The months with the most cloud cover are March and December (Cloud cover 21).
The month with the least cloud cover is August (Cloud cover 5).
Average visibility in December
Pasadena, 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).
