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Triple-digit temperatures changed the record books Tuesday.
Omaha hit 101 degrees. Tekamah, Neb., recorded an astonishing 108, and Sioux City, Iowa, clocked in at 106, the National Weather Service said.
“To say it another way, (it's) the warmest we have ever been this early in the year,” said Barbara Mayes, meteorologist for the weather service.
Meteorologists say quirks in the atmosphere allowed temperatures to spike Tuesday, including unusually dry air settling into the region and an unusual mix of layers of air.
Despite this spring's abundant rains — about 30 percent higher than normal in Omaha — the air is drier than normal.
Why so dry? Mayes said warm, moist Gulf of Mexico air normally flows northward at this time of year, bringing humidity with it. But that flow has been blocked, so the air is dry.
Here's how moisture affects temperature: When the air is moist, the droplets of water have to absorb or release heat before the temperature can change, which slows the process.
When air is dry, temperatures can ricochet up or down, as happens in the desert from day to night. This is one reason Omaha went from a record overnight low of 32 degrees on Sunday to a triple-digit record high on Tuesday, Mayes said.
Because of the hot weather, winds and dry conditions, all of eastern Nebraska and the northern plains are at extreme risk of wildfire, according to the weather service.
There's good news: A cold front moving in is expected to drop today's highs in Omaha into the low 80s.
By 2 p.m., the mercury in Omaha had reached 99 degrees – a temperature not previously seen this early in the year, based on records dating to 1871.
Mayes said several Omaha records fell by the wayside.
• Record high for this date: 96 degrees set on May 14,1915.
• Record earliest 99 degree day or warmer: May 24, 1939, when the high was 99 degrees.
• Record earliest, highest temperature: 97 degrees on May 10, 2011.
• Earliest 100-degree-or-warmer day, May 29, 1934, when Omaha hit 102 degrees.
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|Nebraska highs for Tuesday|
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