May 2025 Monthly Narrative for Northern and Eastern Maine

...MAY 2025 CLIMATE NARRATIVE FOR NORTHERN/EASTERN MAINE...

MAY 2025 FEATURED NORMAL TO SLIGHTLY ABOVE AVERAGE TEMPERATURES AND 
WELL ABOVE NORMAL PRECIPITATION FOR NORTHERN AND EASTERN MAINE. 

TEMPERATURES ACROSS THE REGION RANGED FROM NORMAL TO 1.5 DEGREES (F) 
ABOVE THE 1991-2020 AVERAGES. IN CARIBOU, THE AVERAGE TEMPERATURE OF 
52.2 DEGREES EXACTLY MATCHED THE 1991-2020 AVERAGE FOR MAY. NO MAJOR 
CLIMATE SITE FINISHED IN THE TOP 10 WARMEST FOR THE MONTH OF MAY. 

POSITIVE DEPARTURES FOR THE MONTH WERE MOSTLY DRIVEN BY WARMER THAN 
AVERAGE MINIMUM TEMPERATURES. IN MILLINOCKET, THE AVERAGE MINIMUM 
TEMPERATURE WAS 45.4 DEGREES. THIS WAS 3.6 DEGREES ABOVE AVERAGE, 
AND THE 7TH WARMEST SINCE RECORDS BEGAN IN 1903. ELSEWHERE, AVERAGE 
MINIMUM TEMPERATURES FOR MAY WERE 0.5 TO 2.5 DEGREES ABOVE NORMAL. 
AVERAGE MAXIMUM TEMPERATURES FOR MAY WERE 0.5 TO 2.0 DEGREES BELOW 
NORMAL. NO MAJOR CLIMATE SITE FINISHED IN THE TOP 10 FOR COLDEST 
AVERAGE MAXIMUM TEMPERATURES.

BANGOR FAILED TO RECORD A FREEZE DURING THE MONTH OF MAY FOR THE 
FIRST TIME SINCE 2017. THE AVERAGE DATE OF THE LAST FREEZE IN BANGOR 
IS MAY 10TH. MILLINOCKET AND CARIBOU SAW A FREEZE ON MAY 1ST. 
HOULTON SAW A FREEZE ON MAY 22ND. FROSTS AND FREEZES ARE POSSIBLE AT 
MILLINOCKET, HOULTON, AND CARIBOU INTO JUNE, BUT BECOME LESS COMMON.

THE WARMEST HIGH TEMPERATURES OF THE MONTH IN THE NORTH CAME ON THE 
14TH. MOST NORTHERN LOCATIONS SAW HIGHS REACH THE 80S. CARIBOU SET A 
NEW DAILY RECORD HIGH TEMPERATURE OF 86 DEGREES. THE BANGOR REGION 
AND DOWNEAST SAW THEIR WARMEST TEMPERATURES ON THE 28TH. THE COLDEST 
HIGH TEMPERATURES CAME ON THE 23RD DURING A NOR'EASTER. THAT DAY, 
CARIBOU SET A NEW DAILY RECORD FOR LOWEST MAXIMUM TEMPERATURE (45 
DEGREES).

GREEN-UP WAS OBSERVED IN CARIBOU ON MAY 12TH, WHICH IS AROUND 
THE AVERAGE DATE.

PRECIPITATION (RAIN AND MELTED SNOW) WAS GENERALLY 125 TO 175 
PERCENT OF NORMAL. IN CARIBOU, 5.04 INCHES OF PRECIPITATION FELL 
DURING THE MONTH. THIS MADE MAY 2025 THE 10TH WETTEST MAY IN CARIBOU 
SINCE RECORDS BEGAN IN 1939. TOTAL PRECIPITATION AT BANGOR, 
MILLINOCKET, AND HOULTON FELL SHORT OF THE TOP 10 WETTEST AT EACH 
SITE. NOTABLY, MEASURABLE RAINFALL WAS REPORTED EVERY WEEKEND IN MAY 
AT ALL FOUR MAJOR CLIMATE SITES. THIS PUT A SIGNIFICANT DAMPER ON 
OUTDOOR RECREATION DURING THE MONTH. 

NO SNOWFALL WAS REPORTED AT EITHER CARIBOU OR BANGOR IN MAY. 
NO SEVERE THUNDERSTORM WARNINGS WERE ISSUED DURING THE MONTH.

THE HIGHEST IMPACT EVENT DURING THE MONTH WAS A SLOW-MOVING 
NOR'EASTER FROM THE 23RD TO THE 25TH. RAINFALL TOTALS OF 1 TO 2.5 
INCHES WERE REPORTED FROM THE CENTRAL HIGHLANDS SOUTHWARD, WITH 
LOWER AMOUNTS NORTH. WIND GUSTS UP TO 45 MPH WERE REPORTED AT THE 
COAST. SIGNIFICANT SNOW FELL ON KATAHDIN. PRECIPITATION TYPE 
REMAINED RAIN ELSEWHERE DESPITE UNSEASONABLY COLD TEMPERATURES. 
ANOTHER SIGNIFICANT RAINFALL EVENT CAME ON THE 31ST, WITH 1 TO 2 
INCHES OF RAIN ACROSS MUCH OF THE REGION.

EVAPORATION IN CARIBOU Totaled 4.30 INCHES FOR THE MONTH. THANKS TO 
THE MULTIPLE RAINFALL EVENTS, SOIL MOISTURE WAS WELL ABOVE NORMAL BY 
THE END OF MAY. ACCORDING TO THE U.S. DROUGHT MONITOR, NO PART OF 
NORTHERN AND EASTERN MAINE WAS EVER IN ANY CATEGORY OF DROUGHT 
DURING THE MONTH. 

THE CLIMATE PREDICTION CENTER'S (CPC) OUTLOOK FOR JUNE 2025 
INDICATES THAT THERE IS AN ELEVATED RISK OF ABOVE AVERAGE 
TEMPERATURES IN NORTHERN AND EASTERN MAINE. HOWEVER, THE CPC'S 
OUTLOOK SHOWS NO STRONG CLIMATE SIGNALS FOR ABOVE OR BELOW AVERAGE 
PRECIPITATION.

AT THE START OF THE MONTH OF JUNE, AVERAGE HIGHS RANGE FROM THE 
UPPER 60S IN THE NORTH, TO THE LOWER 70S DEGREES IN BANGOR. AVERAGE 
LOWS RANGE FROM THE MID 40S IN THE NORTH TO THE UPPER 40S AT THE 
COAST. BY THE END OF THE MONTH, AVERAGE HIGHS RISE TO THE UPPER 70S 
FOR MOST OF THE AREA, BUT A BIT COOLER ALONG THE COAST. AVERAGE LOWS 
ARE IN THE MID TO UPPER 50S FOR MOST OF THE AREA BY THE END OF JUNE.

ON AVERAGE, 3.5 TO 4 INCHES OF PRECIPITATION IS OBSERVED 
ACROSS THE AREA DURING THE MONTH OF JUNE. THUNDERSTORMS BECOME AN 
INCREASING THREAT DURING THE MONTH. ON AVERAGE, JUNE PRODUCES THE 
2ND HIGHEST NUMBER OF REPORTS OF SEVERE WEATHER, BEHIND ONLY JULY. 
THE OCCURRENCE OF COASTAL FOG ALSO INCREASES DURING THE MONTH OF 
JUNE.

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NC