March 2010 Climate Report for Puerto Rico and the U.S. Virgin Islands

 

March 2010 Highlights:

Temperatures across Puerto Rico ranged from 51ºF in Adjuntas on the 27th of March to 96ºF in Gurabo on March 21st. Temperatures across the U.S. Virgin Islands ranged from 70ºF, March 7th & 8th at the Cyril E. King and Christiansted Airports respectively, to 89ºF, recorded at the Christiansted Airport on Saint Croix March 30th. Other notable temperatures for March 2010 are listed below:
 

Other Notable March 2010 High’s:
 
95ºF in Rio Piedras on March 17th
95ºF in Aguadilla on March 22nd
94ºF in Trujillo Alto on March 17th
94ºF in Juncos on March 17th   
93ºF in San Juan on March 30th   
93ºF in Ponce on March 23rd  
92ºF in Dos Bocas and Corozal
 
Other Notable March 2010 Low’s:
 
55ºF in Aibonito on March 8th    
56ºF in Maricao on March 8th    
56ºF in Cerro Maravilla on March 6th    
59ºF in Arecibo on March 7th   
63ºF in Rio Piedras, Ponce and Corozal
 

*If multiple occurrences, all dates above reflect the latest occurrence of the month.
 
The highest 24-hour precipitation total across Puerto Rico for the month of March was 6.00”, which fell at Paraiso on the 12th of the month. The highest weekly rainfall across Puerto Rico also occurred at Paraiso, where 8.35” of rain accumulated the week ending March 12th. Across the U.S. Virgin Islands, the highest 24-hour precipitation total was at Corol Bay on Saint John, where 2.40” fell on March 7th. For the week ending March 12th, 3.00” of rain fell at Wintberg on Saint Thomas, representing the highest weekly rainfall across the U.S. Virgin Islands for the month of March.

  

 

Figure 1A – Island wide averaged precipitation (and normals) - by week - for the weeks beginning on January 2nd and ending on April 2nd, 2010

 

 

Figure 1B – Graphical Display of March 2010 precipitation across Puerto Rico and the U.S. Virgin Islands derived from a combination of rain gage and radar data.

 

Monthly Weather Summary: 

 Unseasonable warm temperatures were observed across northern Puerto Rico during the first few days of March 2010. These warm temperatures ended as a strong cold front approached to the local area and brought a significant change in the weather. This cold front prevailed across Puerto Rico and the U.S. Virgin Islands from Friday evening March 5th, 2010 through early Monday morning March 8th, 2010. This weather event broke several records across the local islands. By March 11th, moisture from the southeast brought some clouds and showers across Puerto Rico and the U.S. Virgin Islands. Several flash floods and numerous mudslides were observed across northeastern Puerto Rico during this heavy rain event. Days after, generally fair and dry weather returned as high pressure began to suppress the formation of any significant shower activity and then persisted through the end of the month. Statistically, March 2010 was above normal, in terms of temperature, and slightly above normal in terms of precipitation. The San Juan area averaged 3.1 degrees above normal, and 0.94 inches of rainfall above normal.  

March 2010 Statistics:

 

 
Average March Temperatures/Precipitation (NCDC 1971-2000 averages):
 
 
High:     
Low:     
AvgT:   
Pcpn:      
San Juan              
83.4ºF
71.7ºF   
77.6ºF
2.14”
Saint Thomas
86.5ºF   
72.5ºF   
79.5ºF
1.52”
Saint Croix
85.0ºF
72.3ºF
78.7ºF
1.80”
 
March 2010 Observations:
 
 
High:     
Low:     
AvgT:   
Pcpn:      
San Juan
86.9ºF    (+3.5ºF)
74.5ºF    (+2.8ºF)
80.7ºF    (+3.1ºF)
3.08”      (+0.94”)
Saint Thomas
85.1ºF    (-1.4ºF) 
76.8ºF    (+4.3ºF)
80.9ºF    (+1.4ºF)
1.69”      (+0.17”)
Saint Croix
86.4ºF    (+1.4ºF)
75.3ºF    (+3.0ºF)
80.9ºF    (+2.2ºF)
1.36”      (-0.44”)
 
March 2010 Extremes:
 

 
High:  
Low:  
San Juan
93ºF – March30th
68ºF – March 7th   
Saint Thomas
88ºF – March22nd    
70ºF – March 7th
Saint Croix
89ºF – March 30th
70ºF – March 8th  

 

 

March Historical Statistics:

 
Highest March Temperatures on record:
 
San Juan              
96ºF – March 19th, 1983
95ºF – March 30th, 1984
94ºF – March 21st, 1983*
*Most recent occurrence   
Saint Thomas     
94ºF – March 27th, 26th & 21st 1994
93ºF – March 31st, 1996*
*Most recent occurrence
Saint Croix
92ºF – March 5th, 1996
91ºF – March 24th, 1973*
*Most recent occurrence
 
Lowest March Temperatures on record:
 
San Juan              
60ºF – March 3rd, 1957
61ºF – March 6th, 1970 & March 23rd, 1962
62ºF – March 3rd, 1962*
*Most recent occurrence
Saint Thomas
65ºF – March 24th, 1995
66ºF – March 26th, 1995*
*Most recent occurrence
Saint Croix
60ºF – March 29th, 1977
62ºF – March 20th, 1982*
*Most recent occurrence
 
Wettest Marches:
 
San Juan              
5.41” March 1958
5.17” March 1987
4.83” March 1956
Saint Thomas     
4.37” March 1961
3.95” March 1975
3.73” March 1963
Saint Croix
4.15”  March 1985
3.41”  March 1972
3.31”  March 1988
 
Driest Marches:
 
San Juan              
0.00” March 2005
0.58” March 2008
0.72” March 1970
Saint Thomas
0.01” March 2008
0.01” March 2003*
0.03” March 2007**
Saint Croix
0.17” March 1951
0.29” March 2003
0.39” March 2005

*3 days missing data **6 days missing data

 
 

2000-2010 Decade in Review:

  

 

 

                March 2010 was a month of extremes across Puerto Rico and the U.S. Virgin Islands. The month started off with several 90 degree days across the San Juan metropolitan area, followed by record cold temperatures and record precipitation - both associated with a cold front that stalled across the local islands the first weekend of the month. However, dry weather quickly returned and temperatures quickly rebounded to levels well above normal for this time of year. By the end of the month, the average temperature of 80.7 degrees in San Juan and 80.9 degrees recorded at the airports on both Saint Thomas and Saint Croix, represented temperatures more characteristic of the month of May than the month of March.

 

Over the course of the month, 3 new record high temperatures were recorded in San Juan and 1 new record high temperature was set on Saint Croix. In addtion, a total of 28 new record warm minimum temperatures were recorded between the official reporting sites in San Juan, Charlotte Amalie and Christiansted.  After looking at the decal observations for San Juan, it becomes apparent that March 2010 was indeed a warm month compared to previous decades, in fact, March 2010 ranks now ranks as the warmest March on record at the Christiansted Airport on Saint Croix, the 4th warmest March on record at the Cyril E. King Airport on Saint Thomas and the 3rd warmest March on record at the Luis Muñoz Marin International Airport in San Juan. 

  

Decadal Observations for San Juan, Puerto Rico:

 

 

Decadal March High Temperatures:

2010
2000’s
1990’s
1980’s
1970’s
1960’s
1950’s
88.9ºF
84.8ºF
84.8ºF
85.4ºF
84.3ºF
83.8ºF
84.8ºF

 
 
 
Decadal March Low Temperatures:

2010
2000’s
1990’s
1980’s
1970’s
1960’s
1950’s
74.5ºF
72.4ºF
71.4ºF
71.9ºF
72.4ºF
70.2ºF
67.9ºF

 
Decadal March Average Temperatures:

2010
2000’s
1990’s
1980’s
1970’s
1960’s
1950’s
80.7ºF
78.6ºF
78.1ºF
78.6ºF
78.4ºF
77.0ºF
76.4ºF

 
 
Decadal March Precipitation:

2010
2000’s
1990’s
1980’s
1970’s
1960’s
1950’s
3.08”
1.57”
1.82”
2.29”
2.32”
2.37”
3.27”

 
* Records for San Juan began on January 1st, 1956

 

 
 

 

Figure 2 - Temperature deviations for San Juan, PR

 

Figure 3 - Temperature deviations for Saint Thomas, VI

 

Figure 4 - Temperature deviations for Saint Croix, VI

 

Figure 5 - March 2000's precipitation deviations from normal

 

 Figure 6 - March 2010 precipitation deviations for San Juan, Saint Thomas, and Saint Croix 

 

Looking ahead toward the month of April:

 

Looking ahead, April generally marks the transition to the wet season here in Puerto Rico, with the Luis Muñoz International Airport in San Juan receiving 3.71” of rainfall on average, with a record of 15.00” received in April 2005. However, not all April’s are wet, with the second driest month on record occurring in April 1997, when only 0.08” of rainfall was recorded in San Juan. The average high temperature at the Luis Muñoz International Airport in San Juan for April is 79.1 ºF, 1.5 ºF warmer than March . Presently, El Niño conditions are expected to continue through at least the remainder of the spring, and a detailed summary of these current ENSO conditions and forecasts can be found at:
 
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.pdf
 
 
Average April Temperatures/Precipitation (NCDC 1971-2000 averages):
 

 
High:     
Low:     
AvgT:   
Pcpn:      
San Juan              
84.9ºF
73.2ºF   
79.1ºF
3.71”
Saint Thomas
87.6ºF   
73.9ºF   
80.8ºF
2.39”
Saint Croix
86.2ºF
74.0ºF
80.1ºF
2.00”

 

Moon/Sun/Tide Data for the month of April:

 

  
                The sun rises at 6:19 am AST and sets at 6:38 pm AST, in San Juan, Puerto Rico on April 1st. This represents a total of 12 hours and 19 minutes of daylight. By April 30th, the sun will rise at 5:58 am AST and set at 6:46 pm AST, providing a total of 12 hours and 48 minutes of daylight, or a total increase in 29 minutes over the course of the month.
 
At Charlotte Amalie on Saint Thomas, the sun will rise at 6:14 am AST and set at 6:33 pm AST on the 1st of the month. By the end of the month, the sun will rise at 5:53 am AST and set at 6:41 pm AST, also representing a total increase in daylight of 29 minutes for the month.

                For the month of April, a full moon will be observed on the 28th of the month at 8:18 am AST. There will also be a new moon on the 14th of the month at 8:29 am AST. The last quarter of the moon will be observed on the 6th of April and the first quarter of the new moon will be observed on the 21st of the month.

                Links to additional sunrise/sunset data, phases of the moon, as well as tide data can all be found by clicking on the climate link of the National Weather Service San Juan homepage (www.srh.noaa.gov/sju) and then clicking on the Astronomical tab.
 

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