Climatological Report (Monthly)
Issued by NWS Portland, ME

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33
000 CXUS51 KGYX 032004 CCA CLMPWM PWMCLMPWM 000 TTAA00 KGYX 031805 CLIMATE REPORT NATIONAL WEATHER SERVICE GRAY ME 304 PM EST TUE JAN 3 2017 ................................... ...THE PORTLAND ME CLIMATE SUMMARY FOR THE MONTH OF DECEMBER 2016... CLIMATE NORMAL PERIOD 1981 TO 2010 CLIMATE RECORD PERIOD 1941 TO 2016 /FOR TEMPERATURES/ CLIMATE RECORD PERIOD 1871 TO 2016 /FOR PRECIPITATION/ CLIMATE RECORD PERIOD 1882 TO 2016 /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 53 12/27 56 -3 62 12/25 LOWEST -3 12/16 2 -5 17 12/29 AVG. MAXIMUM 36.6 37.3 -0.7 45.8 AVG. MINIMUM 19.6 20.4 -0.8 30.0 MEAN 28.1 28.8 -0.7 37.9 DAYS MAX >= 90 0 0.0 0.0 0 DAYS MAX <= 32 8 8.7 -0.7 2 DAYS MIN <= 32 27 27.2 -0.2 19 DAYS MIN <= 0 1 0.8 0.2 0 PRECIPITATION (INCHES) RECORD MAXIMUM 9.69 1969 MINIMUM 0.93 1874 TOTALS 5.31 4.02 1.29 5.34 DAILY AVG. 0.17 0.13 0.04 0.17 DAYS >= .01 14 11.5 2.5 15 DAYS >= .10 10 7.2 2.8 12 DAYS >= .50 4 2.6 1.4 4 DAYS >= 1.00 2 1.2 0.8 1 GREATEST 24 HR. TOTAL 1.84 12/29 TO 12/30 SNOWFALL (INCHES) RECORDS TOTAL 54.8 1970 TOTALS 18.9 13.2 5.7 7.3 SINCE 7/1 19.4 15.1 4.3 7.3 SNOWDEPTH AVG. 2 DAYS >= TRACE 13 6.1 6.9 DAYS >= 1.0 5 3.4 1.6 GREATEST SNOW DEPTH 7 12/18 24 HR TOTAL 7.7 12/29 TO 12/30 DEGREE_DAYS HEATING TOTAL 1135 1121 14 831 SINCE 7/1 2387 2612 -225 2077 COOLING TOTAL 0 0 0 0 SINCE 1/1 553 359 194 492 ................................................................. WIND (MPH) AVERAGE WIND SPEED 7.5 HIGHEST WIND SPEED/DIRECTION 32/290 DATE 12/16 HIGHEST GUST SPEED/DIRECTION 43/290 DATE 12/15 SKY COVER AVERAGE SKY COVER 0.50 AVERAGE RH (PERCENT) 68 WEATHER CONDITIONS. NUMBER OF DAYS WITH THUNDERSTORM 1 HEAVY RAIN 2 RAIN 3 LIGHT RAIN 8 FREEZING RAIN 1 LT FREEZING RAIN 3 HEAVY SNOW 2 SNOW 6 LIGHT SNOW 12 FOG 16 FOG W/VIS <= 1/4 MILE 5 HAZE 1 - INDICATES NEGATIVE NUMBERS. R INDICATES RECORD WAS SET OR TIED. MM INDICATES DATA IS MISSING. T INDICATES TRACE AMOUNT. && DECEMBER STARTED ON A WARM NOTE AS THE FIRST TWO DAYS OF THE MONTH SAW THE TEMPERATURE WARM ABOVE 50 DEGREES, BUT THEN THERE WAS A SHIFT TOWARD COLDER WEATHER. A FAIRLY ACTIVE WEATHER PATTERN BROUGHT A NEW STORM SYSTEM TOWARD THE AREA EVERY FEW DAYS OFTEN RESULTING IN SNOWFALL. A QUICK 2 INCHES FELL ON THE 5TH AND THEN ANOTHER 4 INCHES FELL ON THE 12TH. NOT LONG AFTERWARDS AN ARCTIC AIR MASS BROUGHT SOME VERY COLD EARLY WINTER TEMPERATURES. ON THE 16TH THE HIGH TEMPERATURE ONLY REACHED 9 DEGREES, THE COLDEST DECEMBER HIGH TEMPERATURE IN MORE THAN 30 YEARS AND THE SECOND EARLIEST SINGLE DIGIT HIGH TEMPERATURE ON RECORD AT PORTLAND. THE LOW TEMPERATURE ON THE 16TH WAS 3 BELOW ZERO, THE EARLIEST SUBZERO TEMPERATURE SINCE 1989. ANOTHER SNOWSTORM BROUGHT MORE THAN 4 INCHES OF SNOW ON THE 17TH FOLLOWED BY A BRIEF WARM UP BEFORE THE COLDER AIR MOVED BACK IN AGAIN. BY THE 21ST THE BRUTAL COLD HAD EASED UP AND TEMPERATURES CLIMBED BACK TO NEAR OR ABOVE NORMAL FOR THE REST OF THE MONTH, BUT NOT WARM ENOUGH TO PREVENT A WHITE CHRISTMAS FOR THE FIRST TIME IN 3 YEARS. JUST AS THE SNOW PACK BEGAN TO DWINDLE DOWN TO JUST A TRACE, AN INTENSE LOW PRESSURE SYSTEM BROUGHT VERY HEAVY SNOW ON THE NIGHT OF THE 29TH INTO THE EARLY MORNING HOURS OF THE 30TH. THIS STORM BEGAN AS SNOW BEFORE CHANGING TO RAIN FOR SEVERAL HOURS. AS THE RAIN CHANGED BACK TO SNOW IT WAS ACCOMPANIED BY THUNDER AND LIGHTNING AND SNOWFALL RATES IN EXCESS OF 2 INCHES PER HOUR. A TOTAL OF 7.7 INCHES FELL, MOST OF THAT IN JUST A FEW HOURS THAT NIGHT. THE AVERAGE TEMPERATURE FOR THE MONTH WAS 28.1 DEGREES WHICH WAS 0.7 DEGREES BELOW NORMAL AND THE FIRST BELOW NORMAL MONTH AT PORTLAND SINCE APRIL. ALTHOUGH THIS DECEMBER WAS ONLY SLIGHTLY BELOW NORMAL IT WAS NEARLY 10 DEGREES COLDER THAN LAST DECEMBER. DECEMBER 2015 WAS THE WARMEST ON RECORD WITH AN AVERAGE TEMPERATURE OF 37.9 DEGREES. THE COLDEST DECEMBER WAS IN 1989 WHEN THE AVERAGE TEMPERATURE WAS ONLY 14.0 DEGREES. THE HIGH TEMPERATURE ON DECEMBER 16 WAS ONLY 9 DEGREES. THIS WAS THE SECOND EARLIEST SINGLE DIGIT HIGH TEMPERATURE ON RECORD AT PORTLAND AND THE COLDEST DECEMBER HIGH TEMPERATURE SINCE CHRISTMAS DAY 1983. THE FOLLOWING TABLE LISTS THE EARLIEST DAYS IN THE SEASON WHICH DID NOT SEE THE TEMPERATURE RISE OUT OF THE SINGLE DIGITS. EARLIEST SINGLE DIGIT HIGH TEMPERATURES (1940 TO PRESENT)... RANK HIGH DATE 1 9 DEC 12, 1977 2 9 DEC 16, 2016 <=== 3 7 DEC 19, 1942 4 7 DEC 22, 1970 5 9 DEC 24, 1975 6 8 DEC 25, 1968 7 DEC 25, 1983 8 7 DEC 31, 1956 A TOTAL OF 5.31 INCHES OF PRECIPITATION FELL WHICH WAS 1.29 INCHES ABOVE NORMAL. THE HEAVIEST PRECIPITATION FELL ON THE 29TH AND 30TH WHEN 1.84 INCHES OF RAIN AND MELTED SNOWFALL WAS RECORDED. THE WET WEATHER HELPED TO ALLEVIATE DROUGHT CONDITIONS WHICH HAD DEVELOPED DURING THE SUMMER AND EARLY FALL. THE WETTEST DECEMBER ON RECORD WAS IN 1969 WHEN 9.69 INCHES WAS MEASURED. THE DRIEST WAS IN 1874 WHEN ONLY 0.93 INCHES WAS RECORDED. THERE WAS 18.9 INCHES OF SNOWFALL WHICH WAS 5.7 INCHES ABOVE NORMAL. THERE WERE THREE SNOWSTORMS WHICH DROPPED 4 INCHES OR MORE OF SNOWFALL ON THE 12TH, 17TH, AND 29TH TO 30TH. THE HEAVIEST SNOWSTORM WAS ON THE NIGHT OF THE 29TH INTO THE EARLY MORNING OF THE 30TH WHEN 7.7 INCHES WAS MEASURED. SNOW WAS OBSERVED ON THE GROUND ON EVERY DAY EXCEPT THE FIRST 5 DAYS OF THE MONTH. THE SNOWIEST DECEMBER WAS IN 1970 WHEN 54.8 INCHES WAS MEASURED. THE LEAST SNOWY DECEMBER WAS IN 1999 WHEN ONLY A TRACE OF SNOW WAS RECORDED. THE FOLLOWING DAILY RECORDS WERE SET OR TIED IN DECEMBER 2016... DATE RECORD PREVIOUS 16 9 - COLDEST HIGH TEMPERATURE 10 IN 1951 $$ KIMBLE

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.