Weather History for KSFO - December, 2012

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Friday, December 21, 2012

  Actual Average Record
Temperature  
Mean Temperature 55 °F 50 °F  
Max Temperature 58 °F 56 °F 68 °F (1999)
Min Temperature 52 °F 44 °F 28 °F (1990)
Degree Days  
Heating Degree Days 10 15  
Month to date heating degree days 251 295  
Since 1 July heating degree days 846 859  
Cooling Degree Days 0 0  
Month to date cooling degree days 0 0  
Year to date cooling degree days 86 164  
Growing Degree Days 5 (Base 50)    
Moisture  
Dew Point 47 °F    
Average Humidity 74    
Maximum Humidity 93    
Minimum Humidity 55    
Precipitation  
Precipitation 0.32 in 0.15 in 1.73 in (1945)
Month to date precipitation 2.94 2.59  
Year to date precipitation 18.16 19.21  
Since 1 July precipitation 7.70 6.13  
Sea Level Pressure  
Sea Level Pressure 29.91 in    
Wind  
Wind Speed 17 mph (SSE)    
Max Wind Speed 35 mph    
Max Gust Speed 43 mph    
Visibility 8 miles    
Events Rain    
T = Trace of Precipitation, MM = Missing Value Source: NWS Daily Summary

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Date:

Astronomy

Dec. 21, 2012 Rise Set
Actual Time 7:21 AM PST 4:54 PM PST
Civil Twilight 6:51 AM PST 5:24 PM PST
Nautical Twilight 6:18 AM PST 5:57 PM PST
Astronomical Twilight 5:46 AM PST 6:28 PM PST
Moon 12:40 PM PST (12/21) 1:17 AM PST (12/21)
Length of Visible Light 10h 32m
Length of Day
9h 33m
Waxing Gibbous, 66% of the Moon is Illuminated
Dec 21
Waxing Gibbous
Dec 28
Full
Jan 4
Last Quarter
Jan 11
New
Jan 18
First Quarter

Hourly Weather History & Observations

Time (PST) Temp. Dew Point Humidity Pressure Visibility Wind Dir Wind Speed Gust Speed Precip Events Conditions
12:56 AM 54.0 °F 42.1 °F 64% 29.99 in 10.0 mi SE 15.0 mph - N/A   Mostly Cloudy
1:56 AM 53.1 °F 43.0 °F 69% 29.97 in 10.0 mi SE 12.7 mph - N/A   Overcast
2:56 AM 54.0 °F 42.1 °F 64% 29.96 in 10.0 mi ESE 17.3 mph - N/A   Overcast
3:56 AM 53.1 °F 41.0 °F 64% 29.94 in 10.0 mi ESE 15.0 mph - N/A   Overcast
4:56 AM 54.0 °F 41.0 °F 62% 29.93 in 10.0 mi ESE 19.6 mph - N/A   Overcast
5:56 AM 54.0 °F 42.1 °F 64% 29.93 in 10.0 mi ESE 15.0 mph - N/A   Overcast
6:56 AM 54.0 °F 41.0 °F 62% 29.93 in 10.0 mi SE 13.8 mph - N/A   Overcast
7:56 AM 54.0 °F 42.1 °F 64% 29.91 in 10.0 mi ESE 23.0 mph 28.8 mph N/A   Overcast
8:56 AM 55.0 °F 39.9 °F 57% 29.92 in 10.0 mi SE 15.0 mph - N/A   Overcast
9:56 AM 54.0 °F 41.0 °F 62% 29.93 in 10.0 mi SE 18.4 mph 24.2 mph 0.00 in Rain Light Rain
10:56 AM 53.1 °F 46.9 °F 80% 29.92 in 10.0 mi SE 18.4 mph - 0.07 in Rain Light Rain
11:56 AM 53.1 °F 46.9 °F 80% 29.92 in 10.0 mi SE 18.4 mph - 0.04 in Rain Light Rain
12:49 PM 57.2 °F 50.0 °F 77% 29.89 in 8.0 mi South 23.0 mph 29.9 mph 0.00 in Rain Light Rain
12:56 PM 55.9 °F 50.0 °F 80% 29.89 in 5.0 mi South 20.7 mph 35.7 mph 0.00 in Rain Light Rain
1:56 PM 57.0 °F 50.0 °F 77% 29.87 in 9.0 mi South 17.3 mph - 0.01 in Rain Light Rain
2:28 PM 57.2 °F 50.0 °F 77% 29.87 in 8.0 mi South 26.5 mph 38.0 mph 0.00 in Rain Light Rain
2:56 PM 57.0 °F 48.9 °F 74% 29.86 in 9.0 mi South 29.9 mph 42.6 mph 0.00 in Rain Light Rain
3:29 PM 57.2 °F 50.0 °F 77% 29.87 in 5.0 mi South 20.7 mph 36.8 mph 0.00 in Rain Light Rain
3:56 PM 55.9 °F 50.0 °F 80% 29.88 in 3.0 mi South 25.3 mph 38.0 mph 0.00 in   Haze
4:27 PM 55.4 °F 50.0 °F 82% 29.89 in 3.0 mi South 19.6 mph 34.5 mph 0.01 in   Haze
4:49 PM 55.4 °F 48.2 °F 77% 29.90 in 2.5 mi South 20.7 mph 33.4 mph 0.02 in   Haze
4:56 PM 55.0 °F 48.9 °F 80% 29.90 in 5.0 mi South 21.9 mph 28.8 mph 0.03 in   Haze
5:56 PM 55.0 °F 48.9 °F 80% 29.91 in 10.0 mi ESE 8.1 mph - N/A   Overcast
6:56 PM 55.0 °F 48.9 °F 80% 29.91 in 10.0 mi ESE 11.5 mph - N/A   Mostly Cloudy
7:56 PM 55.0 °F 50.0 °F 83% 29.91 in 5.0 mi SSE 10.4 mph - 0.00 in Rain Light Rain
8:56 PM 55.0 °F 50.0 °F 83% 29.91 in 8.0 mi South 18.4 mph - 0.09 in Rain Light Rain
9:08 PM 55.4 °F 50.0 °F 82% 29.90 in 5.0 mi South 19.6 mph - 0.00 in Rain Light Rain
9:56 PM 54.0 °F 52.0 °F 93% 29.90 in 10.0 mi SSE 5.8 mph - 0.05 in Rain Light Rain
10:08 PM 55.4 °F 51.8 °F 88% 29.90 in 9.0 mi SE 10.4 mph 20.7 mph 0.00 in Rain Light Rain
10:26 PM 53.6 °F 50.0 °F 88% 29.89 in 6.0 mi SE 6.9 mph - 0.02 in Rain Rain
10:56 PM 54.0 °F 48.9 °F 83% 29.88 in 10.0 mi SE 12.7 mph - 0.03 in   Overcast
11:10 PM 53.6 °F 48.2 °F 82% 29.87 in 10.0 mi SE 12.7 mph - 0.00 in Rain Light Rain
11:56 PM 57.0 °F 48.9 °F 74% 29.86 in 10.0 mi South 20.7 mph 32.2 mph 0.00 in   Scattered Clouds