September is about to turn hotter | Eye to the Sky


The northern Cumberland Plateau region is off to one of its coolest starts to September ever but that looks to change in the days ahead.

Through the first 12 days of the month, our average high temperature in Oneida barely broke 70 degrees — 71.2, to be exact. That's more than 10 degrees cooler than normal. Our average daily high through the first 12 days of September is a normal year is almost 82 degrees. We have seen only one day with temps of at least 80 degrees thus far this month, and four out of the first 12 days saw temperatures fail to reach 70 degrees. We saw a high of just 61 on Tuesday, 69 on Sept. 7, 68 on Sept. 6, and 59 on Sept. 3.

Add it all up, and our average temperature through the first 12 days of September was 60.6 degrees — exactly nine degrees below normal. It puts this September on pace to be the coolest month of September ever in Oneida. The current record is 1967, when temperatures throughout the month averaged 61.3 degrees.

This comes on the heels of a mild summer overall. The month of August featured high temps that were 2.5 degrees below normal, July was right at its average, and June was 2.1 degrees below normal. We've seen only five days all year with temps at 90 or above (none since July 27).

But that record-cool start to September is about to go out the window, as things flip in a big way. September is a transitional month into fall; temperatures at the end of the month are typically several degrees cooler than at the first of the month. But this September is going to defy the norm, with the second half of the month being much warmer than the first half.

The National Weather Service's Morristown weather forecast office is forecasting a high near 80 on Friday, then climbing into the lower 80s for Saturday-Tuesday. The GFS forecast model is projecting temps of at least 80 degrees each day through the end of its run, which is Sept. 29. In fact, the model suggests that while this weekend will be very warm, the hottest temps will be yet to come. The GFS is forecasting a high in the mid 80s for most of its run beyond Tuesday.

That is a significant change from the weather that we have experienced lately. A lot of folks believe the cool start to fall is going to transition into a colder-than-normal winter. They might change their thinking in the next couple of weeks!

How long will it last? That's unclear. NOAA's Climate Prediction Center is forecasting above-normal heat for much of the eastern U.S. for the next 14 days, but the agency is forecasting below-normal temperatures returning to our region for Weeks 3-4, which is Sept. 23-Oct. 6. That forecast is a bit dated, and was published on Friday. There have been some long-range modeling indications that cool weather is on the way for early October, but that was before the GFS locked on to the heat pattern in the nearer term.

Another trend might be set to change, as well: the CPC is forecasting below-average precipitation for our area for the next 14 days.

Eye to the Sky is a weather blog by Independent Herald editor Ben Garrett. Garrett is a weather enthusiast who has long blogged about interesting weather on his personal website. He is not a professional forecaster or a meteorologist and information on this blog should not be considered a substitute for forecasts, advisories or other products from the National Weather Service.

Ben Garrett is Independent Herald editor. Contact him at Follow him on Twitter, @benwgarrett.