KEY WEST CLIMATE STATISTICS FOR
1999

TEMPERATURE

AVG. MONTHLY MAX. 82.9 F                  AVG. MONTHLY MIN. 73.0 F
DEPARTURE FROM NORMAL + 0.4 F     DEPARTURE FROM NORMAL -0.1 F

AVG. YEARLY TEMP. 77.9 F     DEPARTURE FROM NORMAL: +0.1 F

HIGHEST MONTHLY AVG. TEMP: 84.1 F     MONTH: JULY
LOWEST MONTHLY AVG. TEMP.: 71.4 F     MONTH: FEBRUARY

AVERAGE MONTHLY TEMPERATURE...

LARGEST POSITIVE DEPARTURE FROM NORMAL: 2.3 F     MONTH: JANUARY
" NEGATIVE " " " : 1.9 F     MONTH: MARCH

HIGHEST TEMP.: 92 F     DATE: 7/30, 9/1     LOWEST TEMP.: 52 F     DATE: 1/6
 

 

PRECIPITATION

TOTAL: 47.87 INCHES     DEPARTURE FROM NORMAL: + 8.28 INCHES

GREATEST 24 HOUR RAINFALL: 7.97 INCHES     DATE: OCTOBER 15

GREATEST MONTHLY RAINFALL: 12.55 INCHES     MONTH: OCTOBER

LEAST MONTHLY RAINFALL: 0.42 INCHES     MONTH: NOVEMBER

LARGEST POSITIVE DEPARTURE FROM NORMAL: 8.13 INCHES     MONTH: OCTOBER
" NEGATIVE " " " : 2.42 INCHES     MONTH: NOVEMBER
 

NUMBER OF DAYS WITH...

RAINFALL > 0.01 INCHES: 115 (106 NORMAL)
RAINFALL > 0.10 INCHES: 74
RAINFALL > 0.50 INCHES: 28
RAINFALL > 1.00 INCHES: 10 ( 10 NORMAL)

THUNDERSTORMS: 63 (64 NORMAL)

FOG (VIS. < 6 MILES): 91
FOG REDUCING VIS. TO 1/4 MILE OR LESS: 5 (1.2 NORMAL)

SMOKE/HAZE: 21

WATERSPOUTS: 37

MAX. TEMPS. > 90 F: 42 (40 NORMAL)

COLD FRONTAL PASSAGES: 23 (5 IN MARCH)

TROP. CYCLONES PASSING WITHIN A 50 MILE RADIUS OF EYW: 2
HURRICANE IRENE, TS HARVEY

MISCELLANEOUS

HIGHEST BAROMETRIC PRESSURE: 30.39 INCHES     01/05
LOWEST BAROMETRIC PRESSURE: 29.17 INCHES     10/15

HEATING DEGREE DAYS: 22     DEPARTURE: -78
COOLING DEGREE DAYS: 4,845     DEPARTURE: -43

PEAK WIND/DIRECTION: 54 MPH/NE     DATE: 10/15
HIGHEST SUSTAINED WIND/DIR: 44 MPH/NE     DATE: 10/15
HIGHEST AVERAGE DAILY WIND SPEED: 22.6 MPH DATE: 10/15
 

 

RECORDS

RECORDS SET OR TIED

JANUARY: 5TH; SET RECORD LOW MAXIMUM TEMPERATURE OF 60 F
23rd; SET RECORD HIGH MINIMUM TEMPERATURE OF 77 F
 

MAY: 3RD; SET RECORD LOW OF 65 F

JUNE: 11TH; SET DAILY RECORD RAINFALL OF 2.50 INCHES

AUGUST: 2ND; SET DAILY RAINFALL RECORD OF 2.49 INCHES
14TH; SET DAILY RAINFALL RECORD OF 3.06 INCHES
 

SEPTEMBER: 15TH; SET RECORD HIGH MINIMUM TEMPERATURE OF 83 F
 

OCTOBER: 14TH; SET DAILY RAINFALL RECORD OF 3.77 INCHES
15th; SET DAILY RAINFALL RECORD OF 4.82 INCHES
 

 

SIGNIFICANT WEATHER EVENTS

JANUARY: 5th and 6th; A strong cold front moved through the Keys bringing cold temperatures strong winds. A record low maximum temperature of 60 F was observed on the 5th with lows of 53 and 52 respectively.

MARCH: 3rd and 4th; A squall line oriented NE to SW ahead of a cold front moved through the Keys from the west. A 60 knot wind gust was observed at Sombrero Key and a 41 mph gust at Key West airport.

APRIL: 17th; A squall line moved through the Keys with gusty winds but little rain. A 44 mph gust was measured at the Key West Airport but only 0.14 inches of rain was observed. Quite a bit of dust was blown around by the wind as there had been little rain over the last 2 months.

MAY: 1st; The last cold front of the season passed through the Keys.
30th; A waterspout moved onshore as a F0 tornado along the North end of Key West on Duval Street. No damage was reported.
 

JUNE: 11th; Minor wind damage from thunderstorms occurred in Stock Island. Winds were estimated at 50-60 mph. The Key west airport received 2.50 inches of rain in 3 hours.

AUGUST: 14th; Heavy rain, 3.06 inches, fell from thunderstorms in Key West setting a daily rainfall record. In fact, the total rainfall for August, 9.55 inches is the 7th wettest on record.

SEPTEMBER: 6th; Far outer bands form Hurricane Dennis over the Bahamas moved through the upper Keys producing some waterspouts and one moved onshore in the Rock Harbor area. This tornado was an F0 and caused minor damage.

13th; Powerful Hurricane Floyd (cat 4 at peak) was making residents of the Keys nervous as it was moving west just south of the Bahamas towards the Keys. Fortunately, it moved northwest and north roughly paralleling the east Florida coast.

22nd; Tropical Storm Harvey moved southeast from the Gulf of Mexico over south Florida. Harvey had only minor effects on the Keys.

OCTOBER: 14th; Hurricane Irene moved north across Cuba and its center moved just east of Key West. It was a minimal hurricane and the greatest effects were from the heavy rainfall. Widespread rainfall amounts of 8 to 10 inches were observed across the Keys. Duck Key had the only measured sustained hurricane wind at 75 mph.

15th; 2 tornadoes associated with Hurricane Irene hit areas of the Keys.
One an F0, moved over Boca Chica Key producing minor damage.
Another stronger tornado, F1, moved into the Caloosa Cove area in
the upper keys. Moderate tree and home dama ge occurred with this tornado.

22nd; The first cold front of the season moved through the Keys.

WET SEASON: (May 1-October 31); It was a very wet "wet" season in the Keys. Key West recorded 85% of the annual rainfall (40. 92 inches) during the wet season and normal is 70% (27.30 inches).

DRY SEASON: (November 1-April 30); Conversely, only 15% (6.95 inches) of the annual rainfall fell during this period. Normal is 30% (11.7 inches).
 

***This data is preliminary and unofficial and has not been quality controlled.  For official quality controlled climate data for Key West, contact the National Climatic Data Center at 828-271-4800 or go their web site at http://www.ncdc.noaa.gov.***


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