National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
CXUS53 KDTX 092050 AAA
CLMDTW

CLIMATE REPORT
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
842 AM EDT MON AUG 6 2012

...................................

...THE DETROIT MI CLIMATE SUMMARY FOR THE MONTH OF JULY 2012...

CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1874 TO 2012

WEATHER         OBSERVED          NORMAL  DEPART
                 VALUE   DATE(S)  VALUE   FROM
                                          NORMAL
................................................
TEMPERATURE (F)
RECORD
 HIGH             105   07/24/1934
 LOW               42   07/06/1972
HIGHEST           102   07/17        MM      MM
                        07/04
LOWEST             59   07/21        MM      MM
AVG. MAXIMUM     89.6              83.4     6.2
AVG. MINIMUM     68.4              63.9     4.5
MEAN             79.0              73.6     5.4
DAYS MAX >= 90     13               4.5     8.5
DAYS MAX <= 32      0               0.0     0.0
DAYS MIN <= 32      0               0.0     0.0
DAYS MIN <= 0       0               0.0     0.0

PRECIPITATION (INCHES)
RECORD
 MAXIMUM         8.76   1878
 MINIMUM         0.50   1930
TOTALS           3.67              3.37    0.30
DAILY AVG.       0.12              0.11    0.01
DAYS >= .01         8              10.4    -2.4
DAYS >= .10         5               6.6    -1.6
DAYS >= .50         2               2.0     0.0
DAYS >= 1.00        2               0.8     1.2
GREATEST
 24 HR. TOTAL    1.76   07/05 TO 07/05
 STORM TOTAL       MM
 (MM/DD(HH))            MM

SNOWFALL (INCHES)
RECORDS
 TOTAL            0.0   0
                        0
                        0
TOTALS            0.0               0.0     0.0
 LIQUID EQUIV    0.00              0.00    0.00
SINCE 7/1         0.0               0.0     0.0
 LIQUID 7/1      0.00
DAYS >= TRACE       0               0.0     0.0
DAYS >= 1.0         0               0.0     0.0
GREATEST
 SNOW DEPTH         0   MM
 24 HR TOTAL      0.0   07/31 TO 07/31
 STORM TOTAL       MM
 (MM/DD(HH))            MM

DEGREE_DAYS
HEATING TOTAL       0                 2      -2
 SINCE 7/1          0                 2      -2
COOLING TOTAL     443               271     172
 SINCE 1/1        804               486     318

FREEZE DATES
RECORD
 EARLIEST     MM
 LATEST       MM
EARLIEST                        MM
LATEST                          MM
.................................................

WIND (MPH)
AVERAGE WIND SPEED              6.8
HIGHEST WIND SPEED/DIRECTION    38/320    DATE  07/05
HIGHEST GUST SPEED/DIRECTION    54/320    DATE  07/05

SKY COVER
POSSIBLE SUNSHINE (PERCENT)   MM
AVERAGE SKY COVER           0.60
NUMBER OF DAYS FAIR            4
NUMBER OF DAYS PC             21
NUMBER OF DAYS CLOUDY          6

AVERAGE RH (PERCENT)     61

WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM              8     MIXED PRECIP               0
HEAVY RAIN                4     RAIN                       6
LIGHT RAIN               11     FREEZING RAIN              0
LT FREEZING RAIN          0     HAIL                       0
HEAVY SNOW                0     SNOW                       0
LIGHT SNOW                0     SLEET                      0
FOG                       9     FOG W/VIS <= 1/4 MILE      0
HAZE                     16

-  INDICATES NEGATIVE NUMBERS.
R  INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T  INDICATES TRACE AMOUNT.

$$

-------------------------------------------------------------------
CLIMATOLOGICAL STATISTICS FOR THE NWS WHITE LAKE - JULY 2012

...TEMPERATURE DATA...               ...PRECIPITATION DATA...
AVERAGE MAXIMUM.... 86.3             MONTHLY TOTAL ..........3.75
AVERAGE MINIMUM.... 61.0             GREATEST DAILY TOTAL....1.72
MONTHLY AVERAGE.... 73.7             ON THE 26TH
                                     2012 TOTAL..............15.00

...HEATING DEGREE DAYS...            ...SNOWFALL DATA...

MONTHLY TOTAL..........0             MONTHLY TOTAL..........0.00
2011-12 SEASON TOTAL...0             2011-12 SEASON TOTAL...0.00

...COOLING DEGREE DAYS...
MONTHLY TOTAL.........263
2012 TOTAL............426

=====================================================================
...JULY BRINGS SEVERE THUNDERSTORMS, RECORD HEAT, SEVERE DROUGHT...

THE WARMEST MONTH ON RECORD NATIONALLY WAS THE SECOND WARMEST EVER
RECORDED IN DETROIT. THE AVERAGE TEMPERATURE OF 79.0 FELL JUST -0.3
DEGREES SHORT OF THE ALL-TIME HOTTEST MONTH WHICH OCCURRED EXACTLY
ONE YEAR AGO (JULY 2011). THE HEAT ALSO PROLONGED THE STREAK OF
WARMER-THAN-NORMAL MONTHS FOR DETROIT TO 15, DATING BACK TO MAY
2011. IN SIMILAR FASHION TO LAST SUMMER, EXTREME HEAT QUICKLY BUILT
ACROSS THE SOUTHERN PLAINS AND MIDWEST EARLY IN THE WARM SEASON.
HOWEVER, VERY DRY CONDITIONS ALLOWED THE HEAT TO EXPAND NORTHWARD
MUCH MORE AGGRESSIVELY THAN IN THE YEAR PRIOR. THE RESULT WAS
PROLONGED NEAR-RECORD OR RECORD HEAT ACROSS ALL OF SOUTHEAST
MICHIGAN THAT LASTED NOT ONLY THROUGH JUNE, BUT JULY AS WELL. BY THE
END OF THE MONTH, RECORD HEAT AND DRY AIR HAD RESULTED WIDESPREAD
SEVERE DROUGHT CONDITIONS (D2 ON THE US DROUGHT MONITOR SCALE)
ACROSS SOUTHEAST MICHIGAN. BECAUSE THUNDERSTORMS ARE RELATIVELY
INEFFICIENT AT ALLEVIATING DROUGHT CONDITIONS, THE MULTIPLE EPISODES
OF SEVERE WEATHER THAT OCCURRED DID LITTLE TO EASE DROUGHT CONCERNS.

THE EXTREME HEAT RESULTED IN THE HIGH TEMPERATURE REACHING 90
DEGREES OR HIGHER ON 13 OCCASIONS IN JULY AND 24 TOTAL FOR THE YEAR,
MORE THAN DOUBLING THE ANNUAL AVERAGE OF 11. ALTHOUGH UNLIKELY, THE
CURRENT PACE WOULD BE SUFFICIENT TO AT LEAST CHALLENGE FOR THE
ALL-TIME RECORD OF 39 (1988) 90+ DEGREE DAYS. IN ADDITION, THE
100-DEGREE THRESHOLD WAS TOUCHED 3 TIMES (ON JULY 4TH, 7TH, AND
17TH), MARKING ONLY THE 3RD TIME IN DETROIT`S HISTORICAL RECORD THAT
100 DEGREES HAS BEEN TOUCHED MORE THAN 3 TIMES IN A SINGLE CALENDAR
YEAR. THE HOTTEST TEMPERATURE WAS 102 DEGREES, OBSERVED ON BOTH JULY
4TH AND THE 17TH. THE RECORD WARM START TO THE YEAR WAS ALSO
PROLONGED THROUGH JULY. THE AVERAGE TEMPERATURE OF 54.5 DEGREES
(JANUARY 1ST THROUGH JULY 31ST) EXCEEDS THE PREVIOUS RECORD OF 52.9
(1921) BY AN IMPRESSIVE 1.6 DEGREES. OVERALL, THE AVERAGE
TEMPERATURE FOR THE MONTH WAS 79.0, OR +5.4 DEGREES ABOVE THE 73.6
DEGREE MONTHLY NORMAL, AND THE SECOND WARMEST MONTH ON RECORD.

IN ADDITION TO RECORD HEAT AND SEVERE DROUGHT...SEVERE WEATHER
BECAME ACTIVE FOR THE FIRST TIME THIS SEASON. NUMEROUS SEVERE
WEATHER EPISODES OCCURRED IN JULY, THE MOST NOTABLE OF WHICH WAS IN
THE VERY EARLY MORNING HOURS OF JULY 5TH. WIDESPREAD SEVERE WINDS
CAUSED EXTENSIVE DAMAGE ACROSS MOST OF SOUTHEAST MICHIGAN AS AN
ORGANIZED THUNDERSTORM COMPLEX SURGED FROM NW TO SE ACROSS THE THE
FORECAST AREA. IN ADDITION TO WIDESPREAD WIND DAMAGE, WELL OVER
100,000 HOMES LOST POWER AMIDST CONTINUED RECORD HIGH TEMPERATURES
NEAR 100 DEGREES. A SECOND ORGANIZED OUTBREAK OF SEVERE
THUNDERSTORMS CAUSED ADDITIONAL WIDESPREAD WIND DAMAGE AND POWER
OUTAGES NORTH OF THE I-69 CORRIDOR ON JULY 25TH. ALTHOUGH THE
THUNDERSTORMS HELPED ALSO HELPED TO BOOST ALL CLIMATE SITES TO ABOVE
NORMAL RAINFALL TOTALS, HIGH RAIN RATES ASSOCIATED WITH
THUNDERSTORMS ARE TYPICALLY INEFFECTIVE AT ALLEVIATING DROUGHT
CONDITIONS. THUS, DETROIT, FLINT, AND SAGINAW ROUNDED OUT JULY 2012
WITH RATHER MISLEADING TOTAL RAINFALL FIGURES OF 109%, 107%, AND
172% OF NORMAL RESPECTIVELY.

THE AVERAGE HIGH TEMPERATURE FOR THE DETROIT AREA IN JULY WAS 89.6
+6.2 DEGREES ABOVE THE NORMAL VALUE OF 83.4 AND TIED FOR THE WARMEST
ON RECORD (1955). THE AVERAGE LOW FOR THE MONTH WAS 68.4, +4.5
DEGREES ABOVE THE 63.9 DEGREE NORMAL AND THE 5TH WARMEST ON RECORD.
THE AVERAGE OVERALL TEMPERATURE WAS 79.0, A DEPARTURE OF +5.4 ABOVE
THE 73.6 DEGREE NORMAL AND TIED FOR THE 2ND WARMEST ON RECORD (2011).