Tucsonans Still Outdoors During an Unusually Mild May

There is an unusual feel in the air in Tucson — not a chill, exactly, but unusual all the same.

More people are eating outside. The outdoor fans at Gentle Ben’s Brewing Company — a new feature this summer — have remained strangely quiet, aside from one warm weekend a few weeks ago. People eating outside at Pasco Kitchen & Lounge at night are even asking for the heaters to be turned on.

Such is life here in this unexpected, but pleasant break from the scorching Arizona heat.

The average temperature here in May is 76 degrees, but so far this month, Tucson has had an average temperature of almost 72 degrees — the second coolest period, from May 1 through May 18, in the last 20 years. (Only 1995 was cooler.)

This cool weather is in stark contrast to what Tucsonans have experienced in recent years. Since 1894, eight of the warmest Mays in Tucson have occurred since 1996 according to John Brost of the National Weather Service in Tucson.

“We’re more used to seeing record warm Mays in the last two or three decades,” said Mr. Brost, the science and operations officer at the weather service.

High pressure weather systems tend to develop in May and bring sunny skies, warm temperatures and warm air to the area. But this year, a pattern of low pressure systems have kept the warmer temperatures at bay.

Mr. Brost said Tucson has seen these low pressure systems about once a week. At that frequency, the temperature cools off the air and just as it begins to warm up again, another low pressure system hits and cools the city off again.

One of the causes of these low pressure systems is the presence of El Niño, which occurs when the first few inches of the ocean’s surface near the equator in the Pacific Ocean are warmer than normal, Mr. Brost said. This creates low pressure systems in the Gulf of Alaska that dip down to the southern United States and affect areas like California, Texas and Arizona.

The low pressure systems will dominate Tucson’s weather pattern through the weekend and is expected to keep temperatures below or at the average temperature through early next week.

“So wear your jackets,” Mr. Brost said.

Olivia Blanco, a hostess at Pasco, said she has not seen anything too drastic with the weather, but the cooler temperatures are more apparent at night, when people ask to have the heaters turned on when eating outside.

“That’s how you know they’re from Arizona. They can’t handle the cold.”

— Olivia Blanco

At Gentle Ben’s, Richard Fifer, a general manager there, said that more people have requested seats outside on the patio, which is usually popular during cooler months.

“The weather’s been great for business,” Mr. Fifer said. “Everyone’s wanting to sit outside, which is unusual for this time of the year.”

Reid Park Zoo is also experiencing a rise in attendance. The zoo had about 25,000 visitors by this time of the month last year. This year the number is up 5,000 to 30,000 visitors.

While the weather affects attendance at Reid Park’s fully outdoor facilities, Vivian VanPeenen, education curator, said that new attractions such as an elephant calf, born last August, and camel rides may have also had an impact.

El Rio Golf Course has also experienced a rise in attendance which Martha Crockwell, a shop assistant, attributed to the milder weather.

“And there have been more people golfing in the afternoon than usual,” Ms. Crockwell said, a time of the day when most golfers often seek refuge inside air-conditioned buildings.

“A lot of people come in here and tell me ‘the weather is beautiful,’” she said. “Except for the wind, it’s been really nice.”

It is difficult to predict when Tucson will reach typical temperatures this summer. The thermometer usually hits 100 degrees here around May 26. Though official prediction systems only go out seven days, Mr. Brost said there was a good chance Tucson would not hit 100 degrees until after that date.

“I think most people in Tucson, obviously it’s individually independent, are very happy with this May,” Mr. Brost said.

“We will get hot, fear not,” he added. “It’s still Arizona.”