Climatological Report (Monthly)
Issued by NWS Portland, ME
Issued by NWS Portland, ME
000 CXUS51 KGYX 042314 CLMPWM PWMCLMPWM 000 TTAA00 GYX 020949 CLIMATE REPORT NATIONAL WEATHER SERVICE GRAY ME 548 AM EDT FRI JUN 02 2023 ................................... ...THE PORTLAND ME CLIMATE SUMMARY FOR THE MONTH OF MAY 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 94 05/31/1987 LOW 23 05/09/1956 HIGHEST 89 05/28 84 5 84 05/14 LOWEST 30 05/18 32 -2 31 05/09 AVG. MAXIMUM 66.4 64.2 2.2 65.1 AVG. MINIMUM 43.6 45.5 -1.9 46.3 MEAN 55.0 54.9 0.1 55.7 DAYS MAX >= 90 0 0.4 -0.4 0 DAYS MAX <= 32 0 0.0 0.0 0 DAYS MIN <= 32 1 0.7 0.3 1 DAYS MIN <= 0 0 0.0 0.0 0 PRECIPITATION (INCHES) RECORD MAXIMUM 12.34 2006 MINIMUM 0.49 1965 TOTALS 3.94 3.67 0.27 1.12 DAILY AVG. 0.13 0.12 0.01 0.04 DAYS >= .01 8 12.5 -4.5 6 DAYS >= .10 6 7.1 -1.1 4 DAYS >= .50 2 2.5 -0.5 1 DAYS >= 1.00 1 0.7 0.3 0 GREATEST 24 HR. TOTAL 3.06 04/30 TO 05/01 SNOWFALL (INCHES) RECORDS TOTAL 7.0 1945 TOTALS 0.0 0.0 0.0 0.0 SINCE 7/1 56.5 68.7 -12.2 44.1 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 0.0 DEGREE DAYS HEATING TOTAL 308 325 -17 292 SINCE 7/1 6131 6705 -574 6400 COOLING TOTAL 6 10 -4 11 SINCE 1/1 6 11 -5 11 ................................................................ WIND (MPH) AVERAGE WIND SPEED 9.2 HIGHEST WIND SPEED/DIRECTION 33/110 DATE 05/01 HIGHEST GUST SPEED/DIRECTION 50/110 DATE 05/01 SKY COVER AVERAGE SKY COVER 0.36 AVERAGE RH (PERCENT) 61 WEATHER CONDITIONS. NUMBER OF DAYS WITH THUNDERSTORM 0 HEAVY RAIN 2 RAIN 5 LIGHT RAIN 8 FREEZING RAIN 0 LT FREEZING RAIN 0 HEAVY SNOW 0 SNOW 0 LIGHT SNOW 0 FOG 8 FOG W/VIS <= 1/4 MILE 2 HAZE 1 - INDICATES NEGATIVE NUMBERS. R INDICATES RECORD WAS SET OR TIED. MM INDICATES DATA IS MISSING. T INDICATES TRACE AMOUNT. && THE COOL, CLOUDY, AND DAMP PATTERN THAT DOMINATED THE SECOND HALF OF APRIL PERSISTED INTO THE FIRST WEEK OF MAY. A SIGNIFICANT RAIN EVENT THAT STARTED ON APRIL 30TH CONTINUED INTO MAY 1ST WHERE THE PORTLAND AREA RECEIVED 3.06 INCHES OF RAIN WITH UPWARDS OF 5 TO 6 INCHES FALLING ACROSS THE MOUNTAINS AND CENTRAL MAINE LEADING TO SIGNIFICANT FLOODING. THE PORTLAND AREA WENT ON TO RECORD MEASURABLE PRECIPITATION FOR THE NEXT FOUR DAYS OF THE MONTH WITH TEMPERATURES AVERAGING BELOW NORMAL. THE BLOCKING PATTERN ASSOCIATED WITH THE NEGATIVE PHASE OF THE NAO WAS RESPONSIBLE FOR THIS PROLONGED PERIOD OF DREARY WEATHER, AND THIS PATTERN BROKE DOWN BY THE END OF THE FIRST WEEK OF MAY. A PERIOD OF DRY WEATHER ENSUED, AND WITH THE EXCEPTION OF A COUPLE COOL DAYS AND SEASONABLY COLD NIGHTS, TEMPERATURES AVERAGED ABOVE NORMAL THROUGH THE MIDDLE OF THE MONTH. TOWARDS THE END OF THIS DRY STRETCH OF WEATHER A COLD FRONT CROSSED ON THE 17TH WITH A CANADIAN HIGH PRESSURE SYSTEM BUILDING IN BEHIND THE FRONT. THIS HIGH ALLOWED FOR STRONG RADIATIONAL COOLING WITH THE LAST FREEZE OF THE SEASON OCCURING ON THE MORNING OF THE 18TH WHEN THE LOW TEMPERATURE DROPPED TO 30 DEGREES. A COUPLE DAYS LATER, A COASTAL LOW PRESSURE SYSTEM MERGED WITH A COLD FRONT APPROACHING FROM THE WEST BRINGING SIGNIFICANT RAINFALL TO THE PORTLAND AREA WHEN A STORM TOTAL OF 2.33 INCHES FELL ON THE 20TH INTO THE 21ST. COOL WEATHER FOLLOWED THIS HEAVY RAIN EVENT BEFORE A RIDGE OF HIGH PRESSURE BUILT IN OVER THE NORTHEAST RESULTING IN VERY WARM WEATHER TO CLOSE OUT THE MONTH OF MAY. THE AVERAGE TEMPERATURE FOR THE MONTH WAS 55.0 DEGREES, WHICH WAS 0.1 DEGREE ABOVE NORMAL. THE WARMEST MAY ON RECORD WAS IN 2015 WHEN THE AVERAGE TEMPERATURE WAS 59.5 DEGREES. THE COOLEST WAS IN 1967 WHEN THE AVERAGE TEMPERATURE WAS 47.2 DEGREES. A TOTAL OF 3.94 INCHES OF PRECIPITATION FELL, WHICH WAS 0.27 INCHES ABOVE NORMAL. THE WETTEST MAY ON RECORD WAS IN 2006 WHEN A TOTAL OF 12.34 INCHES OF RAIN FELL. THE DRIEST WAS 0.49 INCHES IN 1965. THE FOLLOWING DAILY RECORDS WERE SET OR TIED IN MAY 2023... DATE RECORD PREVIOUS MAY 3 4 - LOWEST TEMPERATURE RANGE 4 IN 1998 AND OTHERS MAY 18 30 - COLDEST LOW TEMPERATURE 31 IN 1981 AND 1959 $$ DS