The weeks ahead should include the hallmarks of a Lancaster County summer: a few heat waves, around two dozen 90-degree days, unpredictable storms and a dry stretch, according to Millersville University meteorologist Eric Horst.
“When summer is said and done, does it finish up a degree warmer than average and little dryer than average? Perhaps,” Horst said Tuesday.
But for the most part, ordinary summer weather is on tap for Lancaster County.
“I don't see signs that this will turn into an extreme summer,” he said.
With a high over 90 degrees, the second day of a heat wave is likely in Lancaster County today.
The astronomical summer began at 12:24 a.m. today with the summer solstice, Horst said. It ends on Sept. 22. Meteorologists think of summer as the warmest months of the year: June, July and August.
On average, Lancaster County sees 25 90-degree days during the summer. Horst said to expect 25 to 30 90-degree days this year.
Lancaster County already had its first heat wave of the year June 11-13, Horst said. A heat wave is a minimum of three, consecutive 90-degree days.
Short term, Horst said a heat wave is unlikely before the Fourth of July. Beyond the holiday, the warmest weeks of the summer with repeated 90-degree days and dry weather are likely, he said.
“We might see a few weeks on the dry side as our lawns turn brown, but I'm not expecting a drought,” he said.
Summer precipitation is difficult to predict because of the uncertainty of tropical weather, Horst said. But a typical summer pattern of chances of afternoon thunderstorms is likely, he said.
AccuWeather meteorologist Max Vido predicts temperatures will be 1 to 2 degrees above average for June through August.
“This year, we're expecting the warmth to be around but not be as intense,” Vido said.
Last year's summer temperatures in Lancaster County came in at around 3 to 4 degrees above average, Vido said.
So far, June has been above average. July should be close to average, and August should be the warmest month, he said.
“We're expecting a little more heat to build at the end of the summer for the dog days of summer,” he said.
July will have typical hot, humid days with afternoon thunderstorms. But heat waves and soaking rains aren't likely, Vido said.
“It looks like a good month to be outside,” he said.
National Weather Service
National Weather Service meteorologist David Martin said higher than normal temperatures and wetter than normal conditions are likely through the end of July.
Martin said to expect frequent changes in the weather due to cooler air over the northern tier of states interacting with warmer air over the southern states.
There will be days of above average warmth, but Martin said extended heat waves like last summer are unlikely.
“There will be some warm days, some humid days, but not like last summer,” Martin said.
There were three heat waves in Lancaster County last summer, according to data from the Millersville University Weather Information Center: July 6-8, July 22-27 and Aug. 11-16.