Climatological Report (Monthly) Issued by NWS Portland, ME
000
CXUS51 KGYX 011854
CLMPWM
PWMCLMPWM 000
TTAA00 GYX 011821
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