FPUS86 KSGX 020303
OPUSAN

MAY WEATHER IN SAN DIEGO

MAY IS NORMALLY CHARACTERIZED BY PERSISTENT OVERCAST SKIES DURING 
THE NIGHT AND MORNING HOURS AND BY LESS SUNSHINE THAN ANY OTHER 
MONTH EXCEPT JUNE. TEMPERATURES CONTINUE THEIR UPWARD TREND WITH THE 
MOST NOTICEABLE RISE IN NIGHTTIME READINGS.  THE NORMAL DAILY 
MAXIMUM FOR THE MONTH IS 68.5 DEGREES...THE NORMAL DAILY MINIMUM 
59.4 DEGREES AND THE MEAN 64.0 DEGREES. ON 3 DAYS THE RECORD MAXIMUM 
TEMPERATURES WERE 95 OR ABOVE AND WAS 98 DEGREES ON MAY 25...1896 
THE ABSOLUTE HIGH FOR MAY.  HOWEVER...THE COOL SEA BREEZE PREVAILS 
NEARLY EVERY DAY AND TEMPERATURES ABOVE 80 DEGREES ARE RARE.  NIGHTS 
ARE UNIFORMLY MILD AND THE LOWEST READING DURING THE MONTH WAS 45 
DEGREES IN 1915...1894...AND 1883.

OUR LONG DRY SEASON USUALLY BEGINS IN MAY AND THE AVERAGE NUMBER OF 
DAYS WITH MEASURABLE RAIN IS 2 WITH AN AVERAGE  MONTHLY TOTAL OF 
0.12 INCH.  HOWEVER...ON 3 OCCASIONS THE MONTHLY TOTAL HAS EXCEEDED 
2 INCHES WITH THE GREATEST RAINFALL 2.54 INCHES IN 1921.

STORMY WEATHER IS ALMOST UNKNOWN DURING THE MONTH AND WINDS OVER 20 
MPH HAVE BEEN INFREQUENT. ONLY TWICE HAVE WINDS OVER 30 MPH BEEN 
RECORDED AT THE NATIONAL WEATHER SERVICE OFFICE. THE HIGHEST WIND 
EVER RECORDED IN MAY WAS 40 MPH ON MAY 29...1988. THE OTHER TIME 
WINDS OVER 30 MPH WERE RECORDED WAS IN 1922 WHEN WINDS OF 37 MPH 
WERE REGISTERED.

ALTHOUGH SKIES ARE COMMONLY OVERCAST DURING THE NIGHT AND MORNING 
HOURS...HEAVY FOG IS RARE...THE AVERAGE BEING ONLY 1 EACH MAY. CLEAR 
DAYS NUMBER 8...PARTLY CLOUDY 12 AND CLOUDY 11. POSSIBLE SUN SHINE 
IS 58 PERCENT ON ANY GIVEN DAY...ABOUT 11 PERCENT LESS THAN THE 
WINTER DAYS AVERAGE.  MAY AND JUNE ARE THE CLOUDIEST MONTHS OF THE 
YEAR WHICH IS A PARADOX BECAUSE THEY ARE TWO OF THE 5 DRIEST MONTHS 
OF THE YEAR.  RELATIVE HUMIDITY SHOWS LITTLE CHANGE FROM APRIL WITH 
HUMIDITY IN THE EARLY MORNING 77 PERCENT...NEAR NOON 65 PERCENT AND 
IN THE AFTERNOON 64 PERCENT.