On Tuesday, the National Oceanic and Atmospheric Administration (NOAA) released its global temperature data for September. It shows that the month was a scant 0.07°F (0.04°C) below September 2015’s record making it the second-warmest September on record. That ends a streak of 16 consecutive record-setting hot months in NOAA’s dataset, a recordMore
For a large part of the country, the last few days have felt more like the beach-going weather of July than the pumpkin spice latte-sipping weather of October, with record highs blown out of the water thanks to an intense area of high pressure that brought warm air from the southwest.
Some good news for those who love the crisp fall air, though: that warmth is starting to fade away and the weekend looks to be more seasonable. But these sorts of unseasonably warm episodes will only become more common as the planet continues to heat up thanks to human-caused greenhouse gas emissions.
Record high temperatures were often eclipsed, or in some cases, shattered this week. On Sunday, the temperature hit 102°F (39°C) in the Oklahoma Panhandle town of Slapout. According to the Oklahoma state climatologist, that was the state’s highest temperature on record so late in the year.
The next day in Dodge City, Kansas, the old record high of 94°F (34°C), which had held since 1926, was crushed, as the temperature surged to 101°F (38°C). It was also the first 100°F reading on record in October in Dodge City. Nearby Garden City also hit 100°F, breaking their daily record by 5°F. It was the first time in 142 years of records that both of those towns reached 100°F in October.
St. Louis had a couple of noteworthy records. Monday reached 91°F (33°C), the hottest so late in the season there. The same day, the city set a record for the highest minimum temperature, with the low only dropping to at 72°F (22°C), breaking the previous record of 66°F (19°C).
Over on the East Coast, Bridgeport, Conn., surged to 86°F (30°C) on Wednesday, breaking the record for the date as well as for the hottest temperature so late in the season. John F. Kennedy International Airport in New York also hit 86°F on Wednesday, crushing the 51-year-old record for the date by 11°F.
According to the Weather Channel’s Greg Diamond, more than 330 record high and record warm low temperatures have been tied or broken since Saturday. The National Weather Service shared a list of the record highs that were tied or broken in the Eastern U.S. earlier in the week.
As the climate continues to warm because of greenhouse gases accumulating in the atmosphere, such heat extremes will become more common. So while we cannot say climate change caused the October warming, it does mean that extremes of heat, no matter the time of year, will become more frequent.
Similarly, the frequency of record cold lows will decrease. So as the years move forward, temperatures that had been record highs will gradually become more of a regular occurrence, and record lows will become less common.
As Washington’s Capital Weather Gang suggests, the warmer fall weather seems nice. But warm fall days are like pieces of Halloween candy. A little bit is enjoyable, but adding too much of it over time can cause trouble, as there are repercussions for the larger environment.
With warmer fall temperatures, frosts come later, which allows insect populations to thrive longer. Over time, agricultural areas that have long supported certain crops will see them struggle, as the zones that are best for those crops shift northward and upward in elevation.
But even with overall warmer fall temperatures, fall will still be the season where summer’s heat transitions to winter’s cold.
Colder air is already advancing out of Canada, which will end the unusual warmth for most of the country by the weekend. Temperatures will be a bit below normal in the eastern U.S. this weekend. This weather seesaw isn’t unusual for this time of year, as temperatures often do this in the spring and fall transition periods.
However, a new area of warm air is already building in the Southwest, with highs remaining in the 90s in parts of Arizona. So don’t say goodbye to warmer-than-normal weather yet.