August 2025 Monthly Narrative for Northern and Eastern Maine

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

AUGUST 2025 FEATURED NORMAL TO SLIGHTLY BELOW AVERAGE TEMPERATURES 
AND BELOW NORMAL PRECIPITATION FOR NORTHERN AND EASTERN MAINE. 

TEMPERATURES ACROSS THE REGION RANGED FROM NORMAL TO 1.0 DEGREES (F) 
BELOW THE 1991-2020 AVERAGES. IN CARIBOU, THE AVERAGE TEMPERATURE OF 
64.2 DEGREES WAS 0.7 DEGREES BELOW THE 1991-2020 AVERAGE FOR AUGUST. 
NO MAJOR CLIMATE SITE FINISHED IN THE TOP 10 COOLEST FOR THE MONTH 
OF AUGUST. 

DESPITE THE NEGATIVE AVERAGE TEMPERATURE DEPARTURES, ALL FOUR MAJOR 
CLIMATE SITES HAD MAXIMUM TEMPERATURES AVERAGE OUT ABOVE NORMAL FOR 
AUGUST. MAXIMUM TEMPERATURES AVERAGED 1.0 TO 3.0 DEGREES ABOVE 
THE 1991-2020 NORMALS ACROSS THE AREA. THIS WAS MOSTLY DRIVEN BY 
A HEATWAVE THAT OCCURRED BETWEEN THE 10TH AND 13TH. IN CARIBOU, 
THERE WERE FOUR CONSECUTIVE DAYS WITH A HIGH TEMPERATURE OF 90 
DEGREES OR HIGHER. THIS TIED FOR THE LONGEST SUCH STRETCH ON RECORD. 
THE OTHER STRETCHES WERE AUGUST 28TH-SEPTEMBER 1ST, 2010, JULY 25TH-
JULY 28TH 1969, AND JUNE 15TH-JUNE 18TH, 1949. IN ADDITION, THE 10TH 
THROUGH THE 13TH WAS THE WARMEST FOUR-DAY STRETCH ON RECORD FOR 
CARIBOU WHEN AVERAGING BOTH HIGH AND LOW TEMPERATURES (79.0 
DEGREES). THE PREVIOUS RECORD STRETCH WAS JULY 26TH-JULY 29TH, 1963 
(78.9 DEGREES). RECORDS IN CARIBOU DATE BACK TO 1939. MULTIPLE DAILY 
RECORD HIGH TEMPERATURES WERE SET AT CARIBOU, MILLINOCKET, AND 
HOULTON DURING THE HEATWAVE. NO DAILY RECORDS WERE SET IN BANGOR DUE 
TO RECORD HIGHS BEING HIGHER THERE FOR THE RESPECTIVE DAYS.

OUTSIDE OF THE AFOREMENTIONED HEAT WAVE, AUGUST 2025 FEATURED 
NUMEROUS UNSEASONABLY COOL NIGHTS ACROSS THE REGION. MINIMUM 
TEMPERATURES AVERAGED 2.0 TO 3.5 DEGREES BELOW THE 1991-2020 NORMALS 
ACROSS NORTHERN AND EASTERN MAINE. IN HOULTON, THE AVERAGE 
MINIMUM TEMPERATURE FOR THE MONTH WAS 49.0 DEGREES, 3.1 DEGREES 
BELOW NORMAL. THIS WAS THE 9TH COOLEST AVERAGE LOW TEMPERATURE FOR 
THE MONTH OF AUGUST ON RECORD IN HOULTON. RECORDS IN HOULTON 
DATE BACK TO 1948. IN BANGOR, THE AVERAGE LOW TEMPERATURE FOR AUGUST 
WAS 53.5 DEGREES, WHICH WAS 3.5 DEGREES BELOW THE 1991-2020 NORMAL. 
THIS WAS THE 14TH COOLEST AVERAGE MINIMUM TEMPERATURE FOR AUGUST ON 
RECORD IN BANGOR, AND THE COOLEST SINCE 2006 (53.2 DEGREES). RECORDS 
IN BANGOR DATE BACK TO 1925. NEITHER CARIBOU NOR MILLINOCKET 
FINISHED IN THE TOP 20 FOR COOLEST AVERAGE LOW TEMPERATURE FOR 
AUGUST.

THERE WERE 20 DAYS WITH A LOW TEMPERATURE BELOW 50 DEGREES IN 
HOULTON DURING THE MONTH. THIS WAS ONE DAY SHY OF THE RECORD OF 21, 
SET IN 1968. IN MILLINOCKET, THERE WERE 14 DAYS WHERE THE LOW 
TEMPERATURE DROPPED BELOW 50 DEGREES. THIS WAS THE 6TH MOST ON 
RECORD, AND THE LARGEST NUMBER SINCE 1964 (17 DAYS). THE LARGEST 
NUMBER OF DAYS WITH LOWS BELOW 50 DEGREES IN MILLINOCKET IN AUGUST 
OCCURRED IN 1903 (20 DAYS). RECORDS IN MILLINOCKET DATE BACK TO 
1903.

THE COOLEST MORNING OF THE MONTH OCCURRED ON THE 19TH. CARIBOU AND 
HOULTON SAW LOW TEMPERATURES OF 38 AND 35 DEGREES, RESPECTIVELY. 
THIS TIED WITH 2005 AS THE SECOND EARLIEST LOW TEMPERATURE (AFTER 
AUGUST 1ST) OF 38 DEGREES OR LOWER ON RECORD. THE EARLIEST SUCH LOW 
TEMPERATURE OCCURRED ON AUGUST 13TH, 1941 (36 DEGREES). IT WAS ALSO 
THE SECOND EARLIEST (TIED WITH 2005) LOW OF 35 DEGREES OR LOWER IN 
HOULTON ON RECORD. IT WAS JUST TWO DAYS LATER THAN THE RECORD FROM 
AUGUST 17TH, 1979 (35 DEGREES). NUMEROUS LOCATIONS IN NORTHERN MAINE 
SAW EARLY SEASON FROST ON THE 19TH. A WEATHER STATION IN ESTCOURT 
STATION RECORDED A LOW OF 31 DEGREES THAT MORNING.

RAINFALL WAS GENERALLY 40 TO 60 PERCENT OF NORMAL FROM SOUTHEASTERN 
AROOSTOOK COUNTY SOUTHWARD TO DOWNEAST MAINE AND NEAR BANGOR. THIS 
LED TO THE DEVELOPMENT OF SEVERE DROUGHT (D2) CONDITIONS FOR COASTAL 
DOWNEAST DURING AUGUST. MODERATE (D1) DROUGHT CONDITIONS DEVELOPED 
IN THE PISCATAQUIS AND PENOBSCOT VALLEYS EASTWARD INTO INTERIOR 
DOWNEAST AND FAR SOUTHEASTERN AROOSTOOK COUNTY. MOST PLACES SAW 
LITTLE OR NO RAIN DURING THE FIRST HALF OF AUGUST. MODEST RAINFALL 
LATER IN THE MONTH WAS NOT ENOUGH TO MAKE UP FOR THE EARLIER DRY 
SPELL. AREAS FROM THE KATAHDIN REGION NORTHWARD SAW MORE RAINFALL 
DURING AUGUST, GENERALLY 80 TO 90 PERCENT OF NORMAL. RAINFALL 
EVENTS ON THE 23RD-25TH AND 29TH-30TH DROPPED OVER 1.00 INCH OF 
RAINFALL IN PARTS OF THESE AREAS. HOWEVER, ABNORMALLY DRY 
(D0) CONDITIONS STILL DEVELOPED FOR MOST PLACES FROM KATAHDIN 
NORTHWARD. THE EXCEPTIONS WERE THE SAINT JOHN VALLEY AND THE NORTH 
WOODS TOWARD THE QUEBEC BORDER. EVAPORATION IN CARIBOU Totaled 5.08 
INCHES FOR THE MONTH. BY THE END OF THE MONTH, SOIL MOISTURE 
Anomalies WERE BELOW THE 10TH PERCENTILE IN THE BANGOR REGION AND 
DOWNEAST. NORTHERN MAINE HAD SOIL MOISTURE BETWEEN THE 10TH AND 30TH 
PERCENTILE AT THE END OF AUGUST.

FOUR SEVERE THUNDERSTORM WARNINGS WERE ISSUED IN THE MONTH OF 
AUGUST. THREE OF THOSE WERE ISSUED ON THE 14TH IN DOWNEAST MAINE. 
TREE DAMAGE WAS REPORTED ALONG THE ROUTE 1 CORRIDOR NEAR PRINCETON 
AND CALAIS. THE OTHER WARNING WAS ISSUED ON THE 13TH IN THE SAINT 
JOHN VALLEY, WHERE TREE DAMAGE WAS REPORTED.

THE CLIMATE PREDICTION CENTER (CPC) OUTLOOK FOR SEPTEMBER 2025 
INDICATES THAT THERE ARE NO STRONG CLIMATE SIGNALS FAVORING ABOVE 
OR BELOW NORMAL TEMPERATURES IN NORTHERN AND EASTERN MAINE. THE 
CPC OUTLOOK ALSO DOES NOT SHOW ANY STRONG CLIMATE SIGNALS FAVORING 
ABOVE OR BELOW NORMAL PRECIPITATION. AVERAGE HIGH TEMPERATURES ARE 
IN THE LOW TO MID 70S AT THE START OF THE MONTH, DROPPING TO THE 
LOWER TO MID 60S BY THE END OF THE MONTH. AVERAGE LOWS DROP FROM THE 
LOWER 50S EARLY IN THE MONTH TO THE LOWER 40S BY THE END OF THE 
MONTH. FROST INCREASINGLY BECOMES A THREAT IN SEPTEMBER, ESPECIALLY 
IN NORTHERN VALLEYS DURING THE SECOND HALF OF THE MONTH. ALTHOUGH 
VERY RARE, SNOW HAS BEEN OBSERVED ACROSS FAR NORTHERN PORTIONS OF 
THE REGION LATE IN THE MONTH. ON SEPTEMBER 29TH, 1991, CARIBOU 
RECORDED 2.9 INCHES OF SNOW, WHICH IS THE EARLIEST MEASURABLE 
SNOWFALL ON RECORD THERE. SEPTEMBER IS THE MONTH WHERE A TROPICAL 
SYSTEM OR THE REMNANTS OF A TROPICAL SYSTEM IS MOST LIKELY TO AFFECT 
THE AREA.

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NC