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

Highlights

New Records for May 2013

San Juan

Date New Record Previous Record
May 22nd  A 24hr maximum rainfall of 2.53".   This broke previous record of 2.16" set back in 2008. 
May 30th A 24hr maximum rainfall of 1.42". This broke previous record of 1.35" set back in 1992.
May 2013 May 2013 ended as the third wettest May on record with 14.54". May 1936 continued to be the wettest May on record with 16.88".

Saint Thomas 

Date New Record Previous Record
 May 10th A record low temperature of 70 °F. This tied previous record of 70°F set back in 1986. 

Saint Croix   

Date New Record Previous Record
May 2nd  A 24hr maximum rainfall of 1.12".   This tied previous record of 1.12" set back in 1954.
May 26th A 24hr maximum rainfall of 0.22". This broke previous record of 0.21" set back in 1951.
May 2013 May 2013 ended as the 10th coolest May on record with an average temperature of 80.3°F. May 1982 continued to be the coolest May on record with an average temperature of 76.8°F.

May 2013 Statistics

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

  San Juan Saint Thomas Saint Croix
High 87.5°F 87.6°F
86.7°F
Low 76.3°F 76.2°F 76.1°F
Avg. T 81.9°F 81.9°F 81.4°F
Pcpn. 5.90" 3.06" 4.15"

  May 2013 Observations:

  San Juan Saint Thomas Saint Croix
High 87.0°F(-0.5°F) 86.7°F(-0.9°F)
85.8°F(-0.9°F)
Low 75.5°F(-0.8°F) 76.3°F(+0.1°F) 74.8°F(-1.3°F)
Avg. T 81.3°F(-0.6°F) 81.5°F(-0.4°F) 80.3°F(-1.1°F)
Pcpn. 14.54" (+8.64") 4.48" (+0.04") 5.34" (+1.19")

May 2013 Extremes:

  San Juan Saint Thomas Saint Croix
High 91°F May 4th  89°F May 27th and 20th  87°F May 31st, 20th and 19th 
Low  71°F May 27th  70°F May 10th  69°F May 11th

Monthly Summary 

     During the beginning of May 2013, the subtropical high moved northward and loosened its firm grip on weather conditions across the Caribbean. This retreat made way for atmospheric disturbances to penetrate the region including a few tropical waves. In addition, a fairly persistent area of upper level troughiness dominated the forecast area. This resulted in the wettest month of the year so far across Puerto Rico and the third wettest May on record at the San Juan area with 20 days of measurable precipitation.  Overall, the wettest sectors of the island were the north coast and western interior, which both received 200 to 300% of their normal precipitation for the month.

Rainfall Accumulations Year to Date (YTD)    

 

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

 

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

 

Figure C – Graphical display of departure from normal precipitation YTD.

May Historical Statistics        

Highest Temperatures on record:

San Juan Saint Thomas Saint Croix
96°F May 11th 1980  97°F May 23rd 1996   94°F May 28th 1972
96°F May 5th 1980  97°F May 19th 1995   93°F May 25th 1994
95°F May 21st 2005  97°F May 7th 1994  93°F May 30th 1972 

Lowest Temperatures on record:

San Juan Saint Thomas Saint Croix
 66°F May 5th 1962  66°F May 5th 1974   63°F May 4th 1992
66°F May 3rd 1903    68°F May 11th 1986 64°F May 15th 1975 
67°F May 6th 1962   68°F May 7th 1986 64°F May 15th 1972 

Wettest Mays:

San Juan Saint Thomas Saint Croix
16.88"  1936   16.39"   1960 14.03"   1981 
 14.99"  1965  9.98"   1979  11.38"   2001
14.54"   2013  9.80"   1987  8.89"   1987 

 Driest Mays:

San Juan Saint Thomas Saint Croix
0.44"   1972   0.06"   2008 0.22"   1974 
0.48"   1973   0.28"   2007 0.37"   2003 
0.71"   1925  0.47"   1973  0.39"   2002 
   

Decadal May Observations for San Juan, Puerto Rico 

  2010-2013 2000’s 1990’s 1980’s 1970’s 1960’s
High 86.4°F 87.4°F 87.8°F 88.2°F 87.4°F 86.0°F
Low 75.8°F 75.6°F 75.4°F 75.0°F 75.0°F 73.2°F
Avg. T 81.1°F 81.5°F 81.6°F 81.6°F 81.2°F 79.6°F
Pcpn. 10.81" 5.02’’ 4.35’’ 7.59’’ 4.25’’ 6.41’’

Looking ahead toward the month of June

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

  San Juan Saint Thomas Saint Croix
High 88.9°F 89.3°F
87.9°F
Low 77.7°F 77.7°F 78.1°F
Avg. T 83.3°F 83.5°F 83.0°F
Pcpn. 4.41" 2.53" 2.31"

Precipitation Outlook for June-July-August (click here for details)

 

El Niño/Southern Oscillation (ENSO) Diagnostic Discussion 

ENSO-neutral is favored through Northern Hemisphere summer 2013. (click here for details)

Moon/Sun/Tide Data for the month of June 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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