CARIBOU, Maine — The month of May finished with above normal temperatures and below normal precipitation, according to meteorologists at the National Weather Service in Caribou.
May began with some snow on the ground, mostly in the northern woods of Aroostook County, but ended with “near summer conditions with trees at full leaf” by the end of the month. The air mass was very dry throughout the month, with frequent occurrence of frosts and below freezing temperatures deep into May. There were six nights with a low of 32 degrees or lower at Caribou, according to the NWS, the most since 2007.
Nevertheless, temperatures across Aroostook County averaged from 1.0 to 3.5 degrees above average with warm and cool spells alternating in every few days. The average temperature for the month in Caribou was 66.5 degrees, which was four degrees above the normal temperature of 62.3 degrees. The average minimum was 39.3 degrees, which was below the average of 43.2 degrees.
The highest temperature recorded any day last month in Caribou was 87 degrees, which was set on May 31. That compares to 96 degrees recorded on May 22, 1977, as the high for any day in May since records have been kept.
The lowest temperature last month was 28 degrees, recorded on May 12, according to the NWS. The record low temperature for the month in history was 18 degrees, set on May 2, 1974.
In Houlton, the high of 86 degrees this year was recorded on May 31, with the low of 24 recorded on May 12. That compares to a historical high and low of 96 degrees May 29, 1978, and 18 degrees on May 1, 1977.
Houlton saw an average high temperature of 68.4 degrees in May, above the usual average of 63.8 degrees. The town saw an average minimum of 36 degrees, which was 2.5 degrees below the customary average.
May 31 was the warmest day for much of the state, with the temperature exceeding 90 degrees in some locations. Down East experienced the warmest day on May 25, with many locations seeing temperatures in the mid to upper 80’s.
May finished as the eleventh warmest at Millinocket and the 13th warmest at Bangor.
Millinocket saw a high temperature of 88 degrees on May 31, a low of 28 degrees on May 12, and an average of 70.2 degrees for the month, well above its normal average temperature of 64.6 degrees.
Bangor saw a high temperature of 88 degrees on May 2, a low temperature of 31 degrees on May 12 and an average temperature of 69.9 degrees, which was 4.8 degrees above the normal average.
Precipitation was 55 to 70 percent of average across The County with lengthy periods of no rain. Caribou received 2.33 inches of precipitation last month, which was 1 inch below the normal average. The maximum received in May in Caribou was 6.27 inches, which occurred in 1947. The minimum was 0.47 inches in 1982. The most rainfall that fell on the city in a single day last month was 0.97 inches on May 1.
Houlton picked up 2.51 inches of rain for the month, which was 0.79 inches below normal. The greatest 24 hour total was 0.98 inches, which was recorded on May 4.
The most snowfall ever received in May in Caribou was 10.9 inches in 1967. The city did not receive any snow last month, which was 0.5 inches below the normal amount usually received in May. Houlton also did not receive any snowfall in May.
According to meteorologists at the National Weather Service in Gray, the highest temperature for the month was 88 degrees, recorded on May 25. That was two degrees above the normal temperature of 86 degrees. The lowest temperature was 33 degrees, recorded on May 1, which was two degrees below the normal average of 35 degrees for the month. The record high for May in Gray is 95 degrees, which was set on May 18, 2017. The record low is 31 degrees, set on May 1, 2008.
Southern Maine saw a record lack of precipitation last month, picking up just 0.90 inches, below the average of 3 inches for May. The most precipitation ever recorded in Gray for May, 8.54 inches, occurred in 2006. Prior to the new record, the least precipitation ever recorded there was 1.17 inches back in 2001.
