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
With average high temperatures of 64°F (17.8°C) and lows of 50.4°F (10.2°C), December is the coldest month.Humidity
In San Ysidro, the average relative humidity in December is 59%.Rainfall
In December, the rain falls for 6 days. Throughout December, 1.26" (32mm) of precipitation is accumulated. In San Ysidro, California, during the entire year, the rain falls for 57.8 days and collects up to 7.28" (185mm) of precipitation.Daylight
The month with the shortest days is December, with an average of 10h and 6min of daylight.On the first day of the month, sunrise is at 6:32 am and sunset at 4:42 pm. On the last day of December, in San Ysidro, sunrise is at 6:49 am and sunset at 4:53 pm PST.
Sunshine
The month with the least sunshine is December, with an average of 6.6h of sunshine.UV index
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 4. A UV Index estimate of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for the average person.Note: The UV index of 4 during December leads to these advisories:
Be mindful. Those with pale skin might receive burns in fewer than 30 minutes. The Sun's radiation is especially intense around midday; try to stay in shade during this period. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim.
Frequently asked questions
What are the coldest months in San Ysidro?
What is the average December temperature in San Ysidro?
What is the average humidity in December in San Ysidro?
How much does it rain in San Ysidro in December?
What is the month with the shortest days in San Ysidro?
What is the average length of the day in December in San Ysidro?
What time are sunrise and sunset in December in San Ysidro?
What is the month with the least sunshine in San Ysidro?
How many hours of sunshine does San Ysidro have in December?
When is the lowest UV index in San Ysidro?
What is the UV index intensity in December in San Ysidro?
Average temperature in December
San Ysidro, CA
- Average high temperature in December: 64°F
The warmest month (with the highest average high temperature) is August (81.1°F).
The month with the lowest average high temperature is December (64°F).
- Average low temperature in December: 50.4°F
The month with the highest average low temperature is August (66.7°F).
The coldest month (with the lowest average low temperature) is February (50.2°F).
Average pressure in December
San Ysidro, CA
- Average pressure in December: 30.06"Hg
The month with the highest atmospheric pressure is January (30.08"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.88"Hg).
Average wind speed in December
San Ysidro, CA
- Average wind speed in December: 5.2mph
The windiest months (with the highest average wind speed) are April and May (6mph).
The calmest month (with the lowest average wind speed) is October (4.8mph).
Average humidity in December
San Ysidro, CA
- Average humidity in December: 59%
The month with the highest relative humidity is May (68%).
The month with the lowest relative humidity is November (55%).
Average rainfall in December
San Ysidro, CA
- Average rainfall in December: 1.26"
The wettest month (with the highest rainfall) is February (1.5").
The driest month (with the least rainfall) is June (0.08").
Average rainfall days in December
San Ysidro, CA
- Average rainfall days in December: 6 days
The month with the highest number of rainy days is March (7.5 days).
The month with the least rainy days is June (1.8 days).
Average daylight in December /
Average sunshine in December
San Ysidro, CA
- Average daylight in December: 10h and 1min
The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 6min).
- Average sunshine in December: 6h and 4min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 6h and 36min).
Average sunshine days in December
San Ysidro, CA
- Average sunshine days in December: 23.5 days
The month with the most sunshine days is June (27.8 days).
The month with the least sunshine days is February (20.8 days).
Average UV index in December
San Ysidro, 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, November and December (UV index 4).
Average cloud cover in December
San Ysidro, CA
- Average cloud cover in December: 25
The months with the most cloud cover are March and December (Cloud cover 25).
The month with the least cloud cover is August (Cloud cover 8).
Average visibility in December
San Ysidro, 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).
San Ysidro, California, USA
Weather forecast for your location
2. Allow the app to use your location
