August 2013 Climate Report for Puerto Rico and the U.S. Virgin Islands

Highlights August 2013

New Records for August 2013

San Juan

Date New Record Previous Record
 Summer 2013 (JJA) Summer 2013 ended as the 2nd wettest summer on record with 32.89 inches.  Summer 2011 continued to be the wettest summer on record with 43.24 inches. 

Saint Croix   

Date New Record Previous Record
 August 18th A 24hr maximum rainfall record of 2.35 inches of rainfall.  This broke the previous record of 1.32 inches of rainfall set back in 1994. 

Saint Thomas

Date New Record Previous Record
 August 18th A 24hr maximum rainfall record of 2.73 inches of rainfall.     This broke the previous record of 0.70 inches of rainfall set back in 1995.
August 07th A 24hr maximum rainfall record of 1.29 inches of rainfall. This broke the previous record of 0.53 inches of rainfall set back in 1980.
August 05th A 24hr maximum rainfall record of 1.07 inches of rainfall. This broke the previous record of 0.61 inches of rainfall set back in 2006.
August 2013 August 2013 ended as the 4th wettest August on record with 7.69 inches. August 2011 continued to be the wettest August on record with 9.14 inches.
Summer 2013 (JJA) Summer 2013 ended as the 3rd wettest summer on record with 16.36 inches. Summer 2010 continued to be the wettest summer on record with 22.40 inches.

August 2013 Statistics

 Average  August Temperatures/Precipitation (NCDC 1981-2010 averages):

  San Juan Saint Thomas Saint Croix
High 89.2°F 90.2°F 89.2°F
Low 78.2°F 78.2°F 78.4°F
Avg. T 83.7°F 84.2°F 83.8°F
Pcpn. 5.46’’ 3.74’’ 3.15’’

  August 2013 Observations:

  San Juan Saint Thomas Saint Croix
High 89.5°F(+0.3°F) 89.1°F(-1.1°F)
89.8°F(+0.6°F)
Low 78.3°F(+0.1°F) 78.7°F(+0.5°F) 78.3°F(-0.1°F)
Avg. T 83.9°F(+0.2°F) 83.9°F(-0.3°F) 84.1°F(+0.3°F)
Pcpn. 7.42" (+1.96")  7.69" (+3.95") 4.63" (+1.48")

August 2013 Extremes:

  San Juan Saint Thomas Saint Croix
High  94°F August 30th 92°F August 3rd   92°F August 3rd
Low  72°F August 22nd  74°F August 18th  74°F August 11th

Monthly Summary 

     A generally fair weather pattern prevailed across the local islands during August 2013, with afternoon showers and thunderstorms across sectors of the Cordillera Central, western Puerto Rico and portion of the San Juan Metro Area each day. These showers and thunderstorms were the result of available moisture combined with sea breezes and diurnal heating. Scattered to locally numerous showers and thunderstorms were also seen across the local islands from time to time during the month mainly associated with the passage of easterly disturbances and tropical waves.

     August 2013 turned out to be the 4th wettest August on record at the Cyril E. King Airport in Saint Thomas with 7.69 inches. In addition, summer 2013 (June-July-August) ended as the 2nd and 3rd wettest summer on record at LMM Intl Airport in San Juan and Cyril E king Airport with 32.89 and 16.36 inches respectively.

 

Click on image to enlarge

Figure A – Graphical Display of precipitation for August 2013 across Puerto Rico and the U.S. Virgin Islands derived from a combination of rain gage and radar data.

August Historical Statistics              

Highest  August Temperatures on record:

San Juan Saint Thomas Saint Croix
 97°F August 21st, 1980  99°F August 4th, 1994   95°F August 25th, 1999  
96°F August 20th, 1980   99°F August 8th, 1979     95°F August 19th, 1972
96°F August 23rd, 1974    98°F August 13th, 1994  94°F August 4th, 1972  

Lowest August Temperatures on record: 

San Juan Saint Thomas Saint Croix
 68°F August 12th, 1904 64°F August 2nd, 1972 63°F August 17th, 1978  
69°F August 29th, 1916   64°F August 1st, 1972   67°F August 31st, 1979  
69°F August 7th, 1913  67°F August 12th, 1956   67°F August 16th, 1978  

Wettest Augusts:

San Juan Saint Thomas Saint Croix
 18.56"   2011 9.14"   2011  11.41"   1979 
 14.10"   1944  8.54"   1963  11.04"   1989 
 11.76"  1955   8.22"   2005 7.80"   1978 

Driest Augusts:

San Juan Saint Thomas Saint Croix
1.53"   1919  0.70"   1993  1.35"   2005 
 1.83"   1994 0.98"   1991   1.40"   1980
1.93"   1982  1.26"   2002   1.51"   2009

Decadal August Observations for San Juan, Puerto Rico

  2010-2013 2000’s 1990’s 1980’s 1970’s 1960’s
High 89.0°F 89.0°F 89.4°F 89.9°F 88.3°F 87.8°F
Low 78.2°F 77.6°F 77.3°F 77.0°F 77.3°F 75.6°F
Avg. T 83.6°F 83.3°F 83.3°F 83.4°F 82.8°F 81.7°F
Pcpn. 10.46" 5.92" 4.83’’ 5.08’’ 5.27’’ 6.13’’

Looking ahead toward the month of September

Average September Temperatures/Precipitation (NCDC 1981-2010 averages):

  San Juan Saint Thomas Saint Croix
High 89.2°F 90.0°F 89.0°F
Low 77.8°F 77.9°F 77.3°F
Avg. T 83.5°F 84.0°F 83.1°F
Pcpn. 5.77’’ 5.58’’ 4.86’’

Precipitation Outlook SON (click here for details)

September-October-November rainfall likely above- to normal across the region.  

El Niño/Southern Oscillation (ENSO) Diagnostic Discussion (click here for details)

 ENSO neutral is favored into the Northern Hemisphere winter 2013-2014.

 Moon/Sun/Tide Data for the month of September 2013

Sunrise/sunset data, phase of the moon, as well as tide data can all be found by going to the climate portion of the National Weather Service San Juan Climate homepage and then clicking on the astronomical tab  


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