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CLIMATE REPORT
NATIONAL WEATHER SERVICE GRAY ME
221 PM EDT SUN OCT 01 2023

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

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

CLIMATE NORMAL PERIOD: 1991 TO 2020
CLIMATE RECORD PERIOD: 1941 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             95   09/11/1983
                       09/07/1945
 LOW              23   09/30/1941
HIGHEST           88   09/05         86       2       81  09/10
                                                          09/11
LOWEST            43   09/27         37       6       36  09/30
                       09/29
AVG. MAXIMUM    72.8               71.1     1.7     69.5
AVG. MINIMUM    55.4               52.1     3.3     51.0
MEAN            64.1               61.6     2.5     60.3
DAYS MAX >= 90     0                0.5    -0.5        0
DAYS MAX <= 32     0                0.0     0.0        0
DAYS MIN <= 32     0                0.1    -0.1        0
DAYS MIN <= 0      0                0.0     0.0        0

PRECIPITATION (INCHES)
RECORD
 MAXIMUM       10.84   2008
 MINIMUM        0.30   1948
TOTALS          4.91               3.77    1.14     4.20
DAILY AVG.      0.16               0.13    0.03     0.14
DAYS >= .01        8                9.3    -1.3        9
DAYS >= .10        6                5.3     0.7        5
DAYS >= .50        3                2.3     0.7        3
DAYS >= 1.00       1                1.0     0.0        2
GREATEST
 24 HR. TOTAL   3.24   09/18 TO 09/19

SNOWFALL (INCHES)
RECORDS
 TOTAL             T   1992
TOTALS           0.0                0.0     0.0      0.0
SINCE 7/1        0.0                0.0     0.0      0.0
SNOWDEPTH AVG.     0
DAYS >= TRACE      0                0.0     0.0
DAYS >= 1.0        0                0.0     0.0
GREATEST
 SNOW DEPTH        0
 24 HR TOTAL       0

DEGREE DAYS
HEATING TOTAL    100                145     -45      162
 SINCE 7/1       119                173     -54      163
COOLING TOTAL     80                 43      37       28
 SINCE 1/1       422                444     -22      542
................................................................

WIND (MPH)
AVERAGE WIND SPEED              5.7
HIGHEST WIND SPEED/DIRECTION    31/230    DATE  09/08
                                31/320          09/16
HIGHEST GUST SPEED/DIRECTION    46/290    DATE  09/16

SKY COVER
AVERAGE SKY COVER           0.47

AVERAGE RH (PERCENT)     79

WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM              2     HEAVY RAIN                 3
RAIN                      4     LIGHT RAIN                 9
FREEZING RAIN             0     LT FREEZING RAIN           0
HEAVY SNOW                0     SNOW                       0
LIGHT SNOW                0     FOG                       14
FOG W/VIS <= 1/4 MILE     2     HAZE                       3

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

&&

AFTER A WET SUMMER IN THE PORTLAND AREA, A BROAD AREA OF HIGH
PRESSURE BUILT INTO THE NORTHEAST DURING THE FIRST WEEK OF
SEPTEMBER. THIS HIGH PRESSURE BROUGHT THE DRIEST STRETCH OF WEATHER
THE PORTLAND AREA HAD SEEN SINCE THE END OF MAY. ALONG WITH DRY
WEATHER, TEMPERATURES CLIMBED WELL ABOVE NORMAL DURING THE FIRST
WEEK OF SEPTEMBER. IT WAS ALSO DURING THIS TIME THAT TROPICAL
ACTIVITY WAS INCREASING IN THE ATLANTIC BASIN. SOME FRONTAL SYSTEMS
BROUGHT A RETURN TO WET WEATHER DURING THE SECOND WEEK OF SEPTEMBER
BEFORE ATTENTION TURNED TO HURRICANE LEE THAT WAS TRACKING NORTHWARD
THROUGH THE WESTERN ATLANTIC. LEE MOVED INTO THE EASTERN GULF OF
MAINE ON THE 15TH AS A CATEGORY 1 HURRICANE AND TRANSITIONED TO A
POST TROPICAL SYSTEM ON THE 16TH AS IT TRACKED NORTHEASTWARD THROUGH
THE BAY OF FUNDY. THIS SYSTEM BROUGHT HIGH SURF AND RIP CURRENTS TO
AREA BEACHES ALONG WITH A PEAK WIND GUST TO 46 MPH ON THE 16TH WHILE
THE BULK OF RAIN MISSED THE PORTLAND AREA TO THE EAST. A MORE
SIGNIFICANT RAIN EVENT OCCURRED ON THE 18TH INTO THE 19TH WHEN LOW
PRESSURE TRACKED ACROSS CAPE COD INTO THE GULF OF MAINE BRINGING
3.24 INCHES OF RAIN. HIGH PRESSURE BUILT INTO THE NORTHEAST DURING
THE THIRD WEEK OF SEPTEMBER AND DOMINATED THE WEATHER PATTERN
THROUGH THE END OF THE MONTH.

THE AVERAGE TEMPERATURE FOR THE MONTH WAS 64.1 DEGREES, WHICH WAS
2.5 DEGREES ABOVE NORMAL AND TIED FOR THE THIRD WARMEST SEPTEMBER ON
RECORD. THE WARMEST SEPTEMBER ON RECORD WAS IN 2015 WHEN THE AVERAGE
TEMPERATURE WAS 65.3 DEGREES. THE COOLEST WAS 54.5 DEGREES IN 1950. THE
FOLLOWING TABLE LISTS THE WARMEST SEPTEMBERS ON RECORD AT PORTLAND.

WARMEST AVERAGE TEMPERATURE IN SEPTEMBER (SINCE 1941)...
RANK  TEMP  YEAR
1     65.3  2015
2     64.6  2017
3     64.4  2023  <===
4     64.1  1961
5     63.8  2016
6     63.6  2018
      63.6  2005
8     63.4  2020
      63.4  2010
10    63.3  2021
      63.3  1999

A TOTAL OF 4.91 INCHES OF PRECIPITATION FELL, WHICH WAS 1.14 INCHES
ABOVE NORMAL. THE HEAVIEST PRECIPITATION OCCURRED ON THE 18TH INTO
THE 19TH WHEN 3.24 INCHES OF RAIN FELL. THE WETTEST SEPTEMBER ON
RECORD WAS IN 2008 WHEN 10.84 INCHES OF PRECIPITATION FELL. THE
DRIEST WAS 0.30 INCHES IN 1948.

THE FOLLOWING DAILY RECORDS WERE SET OR TIED IN SEPTEMBER 2023...
DATE    RECORD                                 PREVIOUS
SEP  5    77   - WARMEST AVERAGE TEMPERATURE   76 IN 1961
SEP  6    68   - WARMEST LOW TEMPERATURE       66 IN 2018 AND OTHERS
SEP 18   2.29  - GREATEST PRECIPITATION        1.65 IN 2004

$$

DS/SB