It’s never been hotter.
According to measurements taken by the National Weather Service here, July 2018 was the warmest month ever recorded in Juneau. Instruments at Juneau International Airport, the city’s official measuring point, recorded an average July temperature of 61.2 degrees, making it the warmest July recorded in a record that dates back to 1936.
The previous record was 60.2 degrees, set in 1951. Three of the top five hottest Julys have come since 2009. A normal July averages 56.9 degrees.
July is Juneau’s hottest month, meaning any record-breaking warm July will also set the record for all other months..
According to the weather service measurements, July’s warmth wasn’t the result of a handful of warm days: It was the result of consistently high temperatures throughout the month.
There were 18 days with high temperatures above 70 degrees, and of those, four were above 80 degrees.
Over the past 50 years, Juneau has averaged two 80-degree days each year. July 2018 doubled that in a single month, including a pair of 84-degree days on July 4 and July 5 that are among the five hottest days on record, if ties are included.
The month’s warm and sunny weather came courtesy of a pressure ridge that formed in the Gulf of Alaska in the middle of the month. From July 19 through the end of the month, that ridge acted like a shield, diverting storms away from Southeast Alaska and keeping skies clear.
In addition to warmth, the conditions of the past month brought extraordinarily dry weather as well. With only 2.82 inches of rain, it was the city’s driest July since 2009 and the 13th driest overall.
The warm, dry weather wasn’t limited to Juneau: it stretched across Southeast Alaska. Ketchikan saw its second-warmest July on record, as did Skagway. Klawock, Sitka, Petersburg, Haines, Yakutat, and every other community in Southeast had temperatures well above normal.
While the sunshine and warmth brought people in droves to the region’s beaches and trails, it was the dryness that had the biggest effects.
Southern Southeast officially entered a drought during the month, and northern Southeast was rated “abnormally dry.”
In Ketchikan, the fire department issued a burn ban as a precaution against wildfires. On Prince of Wales Island, hydroelectric reservoirs are so low that electric power providers are using diesel backup generators.
Relief appears to be in the forecast as the new month begins. Wednesday was expected to be a day of transition as the blocking ridge moved eastward, allowing rain and cooler conditions to reach Southeast Alaska.
The forecast calls for clouds and a chance of drizzle on Thursday before full-fledged rain over the weekend and into next week.
That rainy, cool pattern is expected to last for at least a week and possibly longer.
• Contact reporter James Brooks at jbrooks@juneauempire.com or 523-2258.
