Climatological Report (Monthly)
Issued by NWS Portland, ME

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CLIMATE REPORT
NATIONAL WEATHER SERVICE GRAY ME
1257 PM EST TUE JAN 02 2024

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

...THE PORTLAND ME CLIMATE SUMMARY FOR THE MONTH OF DECEMBER 2023...

CLIMATE NORMAL PERIOD: 1991 TO 2020
CLIMATE RECORD PERIOD: 1940 TO 2023 (FOR TEMPERATURES)
CLIMATE RECORD PERIOD: 1871 TO 2023 (FOR PRECIPITATION)
CLIMATE RECORD PERIOD: 1882 TO 2023 (FOR SNOWFALL)

WEATHER         OBSERVED          NORMAL  DEPART   LAST YEAR`S
                VALUE   DATE(S)   VALUE   FROM     VALUE DATE(S)
                                          NORMAL
................................................................
TEMPERATURE (F)
RECORD
 HIGH             71   12/06/2001
                       12/07/1998
 LOW             -21   12/31/1963
HIGHEST           59   12/18         56       3       54  12/03
                                                          12/23
LOWEST            13   12/07          2      11       12  12/25
AVG. MAXIMUM    42.4               38.3     4.1     39.5
AVG. MINIMUM    28.1               22.4     5.7     24.4
MEAN            35.2               30.3     4.9     31.9
DAYS MAX >= 90     0                0.0     0.0        0
DAYS MAX <= 32     4                8.4    -4.4        7
DAYS MIN <= 32    20               26.7    -6.7       26
DAYS MIN <= 0      0                0.4    -0.4        0

PRECIPITATION (INCHES)
RECORD
 MAXIMUM        9.69   1969
 MINIMUM        0.93   1874
TOTALS          6.67               4.50    2.17     3.98
DAILY AVG.      0.22               0.15    0.07     0.13
DAYS >= .01       12               12.3    -0.3       11
DAYS >= .10        8                7.9     0.1        5
DAYS >= .50        5                2.9     2.1        3
DAYS >= 1.00       3                1.3     1.7        3
GREATEST
 24 HR. TOTAL   2.47   12/10 TO 12/11

SNOWFALL (INCHES)
RECORDS
 TOTAL          54.8   1970
TOTALS           0.5               14.6   -14.1      4.7
SINCE 7/1        0.7               17.1   -16.4      4.7
SNOWDEPTH AVG.     T
DAYS >= TRACE      4                6.0    -2.0
DAYS >= 1.0        0                3.3    -3.3
GREATEST
 SNOW DEPTH        T
 24 HR TOTAL     0.5   12/04 TO 12/05

DEGREE DAYS
HEATING TOTAL    913               1074    -161     1016
 SINCE 7/1      2182               2451    -269     2252
COOLING TOTAL      0                  0       0        0
 SINCE 1/1       423                446     -23      542
................................................................

WIND (MPH)
AVERAGE WIND SPEED              6.5
HIGHEST WIND SPEED/DIRECTION    40/150    DATE  12/18
HIGHEST GUST SPEED/DIRECTION    59/160    DATE  12/18

SKY COVER
AVERAGE SKY COVER           0.62

AVERAGE RH (PERCENT)     79

WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM              0     HEAVY RAIN                 4
RAIN                      6     LIGHT RAIN                13
FREEZING RAIN             0     LT FREEZING RAIN           0
HEAVY SNOW                0     SNOW                       0
LIGHT SNOW                3     FOG                       16
FOG W/VIS <= 1/4 MILE     4     HAZE                       1

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

&&

DECEMBER WAS A MILD AND WET MONTH IN THE PORTLAND AREA. THE MONTH
STARTED OFF WITH A FRONTAL BOUNDARY NORTH OF NEW ENGLAND THAT
SHIFTED SOUTH BETWEEN THE 3RD AND 5TH OF THE MONTH. WAVES OF LOW
PRESSURE TRACKED ALONG THIS FRONT THAT BROUGHT THE ONLY MEASURABLE
SNOWFALL TO PORTLAND WHEN 0.5 INCHES WAS RECORDED BETWEEN THE 4TH
AND 5TH. A BRIEF PERIOD OF BELOW NORMAL TEMPERATURES FOLLOWED BEFORE
AN AREA OF LOW PRESSURE TRACKED OVER WESTERN NEW ENGLAND THE 10TH
INTO THE 11TH. THIS SYSTEM BROUGHT HEAVY RAIN TO MUCH OF MAINE WITH
PORTLAND RECEIVING 2.47 INCHES FROM THIS SYSTEM. ANOTHER STRONG LOW
PRESSURE SYSTEM IMPACTED NEW ENGLAND ON THE 17TH AND THE 18TH WHEN
IT TRACKED FROM THE EAST COAST OF FLORIDA NORTHWARD THROUGH UPSTATE
NEW YORK. THIS SYSTEM BROUGHT SIGNIFICANT RAINFALL TO THE REGION
WITH CATASTROPHIC FLOODING IN THE MOUNTAINS AND FOOTHILLS ALONG WITH
DAMAGING SOUTHEAST WINDS. PORTLAND RECEIVED 2.32 INCHES OF RAINFALL
AND A PEAK WIND GUST OF 59 MPH FROM THIS SYSTEM. QUIET WEATHER
FOLLOWED UP UNTIL THE 23RD WHEN A DREARY WEATHER PATTERN SET IN OVER
CHRISTMAS WEEKEND THAT PERSISTED UNTIL THE END OF THE MONTH.

THE AVERAGE TEMPERATURE FOR THE MONTH WAS 35.2 DEGREES, WHICH WAS
4.9 DEGREES ABOVE NORMAL AND THE SECOND WARMEST DECEMBER ON RECORD.
THE WARMEST DECEMBER ON RECORD WAS IN 2015 WHEN THE AVERAGE
TEMPERATURE WAS 37.9 DEGREES. THE COOLEST WAS 14.0 DEGREES IN 1989.
THE FOLLOWING TABLE LISTS THE WARMEST DECEMBERS ON RECORD.

WARMEST AVERAGE TEMPERATURE IN DECEMBER (SINCE 1940)...
RANK  TEMP  YEAR
1     37.9  2015
2     35.2  2023  <===
3     34.8  2001
4     34.5  2006
      34.5  1996
6     33.7  2014
7     33.6  1990
8     33.5  1973
9     33.3  2011
10    33.0  1953

A TOTAL OF 6.67 INCHES OF PRECIPITATION FELL, WHICH WAS 2.17 INCHES
ABOVE NORMAL. THE HEAVIEST PRECIPITATION FELL ON THE 10TH INTO THE
11TH WHEN 2.47 INCHES OF RAIN WAS MEASURED. THE WETTEST DECEMBER ON
RECORD WAS IN 1969 WHEN 9.69 INCHES FELL. THE DRIEST WAS 0.93 INCHES
IN 1874.

ONLY 0.5 INCHES OF SNOW FELL, WHICH WAS 14.1 INCHES BELOW NORMAL AND
THE 2ND LEAST SNOWY DECEMBER ON RECORD. THE LEAST SNOWY DECEMBER ON
RECORD WAS IN 1999 WHEN ONLY A TRACE WAS RECORDED. THE SNOWIEST WAS
IN 1970 WHEN 54.8 INCHES FELL.

THE FOLLOWING DAILY RECORDS WERE SET OR TIED IN DECEMBER 2023...
DATE    RECORD                                 PREVIOUS
DEC  4    2   - SMALLEST TEMPERATURE RANGE     6 IN 2005
DEC 11  1.99  - GREATEST PRECIPITATION      1.27 IN 1969
DEC 18   59   - WARMEST HIGH TEMPERATURE      53 IN 1996
DEC 18   46   - WARMEST LOW TEMPERATURE       39 IN 1996
DEC 18   53   - WARMEST AVERAGE TEMPERATURE   46 IN 1996
DEC 28   37   - WARMEST LOW TEMPERATURE       37 IN 2014, 2008 (TIED)
DEC 28    3   - SMALLEST TEMPERATURE RANGE     4 IN 1940
DEC 29    3   - SMALLEST TEMPERATURE RANGE     4 IN 1959 AND 1942

$$

DS


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