This hot, dry September is finally drawing to a close.
Richmond has logged some impressive observations, but this month will narrowly miss out on the titles of hottest or driest September.
Averaging the observed highs and lows for the first 27 days of the month, plus the forecast for the final three, yields a mean of about 76.1 degrees. That’s 5.5 degrees above the normal monthly mean, which is based on the 1981 to 2010 climatology. It’s closer to a typical August, which averages 77.5 degrees.
This will likely rank as Richmond’s third-warmest September, behind 1921 (76.8 degrees) and 2018 (76.4) and just ahead of 1900 (75.7).
Compared with the warm, humid September of 2018, the highs have been hotter this time, but the lows have been cooler (though still mild). That’s consistent with going from an unusually wet pattern to a very dry one.
Every site in the state experienced a hotter-than-normal September, with areas west of Interstate 95 seeing the greatest departures, to the tune of 5 to 8 degrees.
The statewide monthly mean temperature will be published by the National Centers for Environmental Information by mid-October. This will be Virginia’s sixth consecutive year with a September that was warmer than the 20th-century average.
Chances for hit-or-miss thundershowers on Saturday and Sunday could give a last-minute boost to the parched rain totals.
As of Sept. 27, Richmond International Airport had 0.42 inch of rain on the month. That’s the third-driest September for the airport site behind 2005 and 1978. Looking at extended area records since the late 1800s, it is tied for fourth-driest.
If moisture fails to materialize by Monday evening, this will be the driest September for Danville and tied for driest at Arlington County, and tied for second-driest at Lynchburg.
Look for the next update in October.