July 2019 will go down in the record books as the warmest month on record in Portland since forecasters started compiling weather data nearly eight decades ago.

The average temperature this July was 72.9 degrees, placing it above the previous warmest month, July 2011, when the temperature averaged 72.7 degrees.

Several weather patterns and factors contributed to the heat that left Portland sizzling in record-setting heat in July, James Brown, a meteorologist with the National Weather Service Office in Gray, said on Wednesday.

Temperatures at the Portland Jetport reached 80 degrees or more on 24 days in July – putting Portland 3.6 degrees above the average for the month, according to the National Weather Service. Forecasters said the data collected is still preliminary and must be reviewed, but it’s clear July was an extremely hot and humid month.

Haven Kreis, 13, jumps a boogie board from a makeshift waterslide into a kiddie pool while other South Portland neighborhood kids await their turn on Wednesday. Ben McCanna/Staff Photographer

The weather service said the consistent stretch of heat also included four days when the temperatures reached 90 degrees or more. Brown said the jetport reported 90 degrees around 1:30 p.m. on Wednesday, but that did not break the record for July 31. That was set in 1975, when a high of 95 degrees was reported.

July 2019 now tops the list of the 10 warmest Julys in Portland since the weather service began collecting data in 1941.


Ryan Breton, a weather forecaster with News Center Maine, said several factors may have contributed to the heat we’ve suffered through in greater Portland. He said warmer and more humid summers are a symptom of a changing climate.

In his Wednesday blog, Breton described the urban heat island effect, which means Portland retains heat at night unlike surrounding valleys that cool on dry nights. Breton said it’s his opinion that a warmer ocean – on some days this month the water has warmed to nearly 70 degrees – may be affecting overnight temperatures in Portland.

“This is one important connection to climate change: warmer oceans,” Breton said. “While it’s impossible to say this month is breaking records because of climate change, the Gulf of Maine is warming and our changing climate is in the background.”

Many forecasters are reluctant to talk about climate change and its impact on weather due to it being a politically charged topic. In the past, President Trump has claimed that climate change is a hoax and dismissed a landmark scientific report produced by federal government scientists.

But the Washington Post reported that Alaska is experiencing a sweltering summer this year that is breaking records. Alaska is warming faster than any other state, having heated up more than 2 degrees Celsius, or 3.6 degrees Fahrenheit, over the past century, which is double the global average, the Washington Post reported.

Wildfires have been rampaging across Alaska this summer, with more than 2 million acres having burned. Stores have sold out of of fans and ice. And moose in Alaska have been spotted seeking relief from the heat by standing near garden sprinklers.


The warming trend, driven in part by the burning of fossil fuels, is transforming America’s only Arctic state. Temperatures have been above average across Alaska since April 25, the Washington Post reported. None of the state’s 300 weather stations has recorded a temperature below freezing since June 28 – the longest stretch in at least 100 years.

In Siberia, sweeping wildfires are sending smoke thousands of miles and lofting dark soot particles onto the Arctic ice cover.

Record high temperatures gripped Europe in late July. The Washington Post reported that the hottest weather ever recorded swept through Paris, London, Britain, Belgium, the Netherlands and Germany recently. That heat dome moved into Norway, Sweden and Finland, with Norway setting a record high on July 26 of 91 degrees.

Brown, the weather service meteorologist in Gray, said relief from the heat and humidity should arrive in Maine on Thursday.

“The rest of the week is looking warm, but not super hot,” Brown said. “The dew points are going down so it’s going to feel a lot better.”

While the Maine Department of Environmental Protection did issue an air quality alert for most of the state Tuesday, Wednesday’s forecast was elevated to unhealthy along coastal regions for sensitive groups – people with heart or lung disease, the elderly, teenagers and children.

Thursday’s forecast calls for good air quality over the entire state.

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