February in Raleigh is known for rollercoaster temperatures

I decided to go back over the last 20 years and see just how many times afternoon temperatures had a 20°+ swing over 48 hours. The numbers may just surprise you!

Here is what I found:

On average, February’s between 2011 to most of 2020 saw roughly 5 (4.8) 20°+ swings in temperatures over a 48-hour period. Compare that to roughly 3 (2.7) major swings in Februarys between 2001 and 2010. In total, February’s through the last 20 years had roughly 4 (3.75) swings in afternoon temperatures of 20° or more in 48 hours.

So, why have February's in the last decade seen far more swings than the previous decade? I turned to the El Nino Southern Oscillation (ENSO), an oscillation that highly influences winter conditions in our area, to see if it’s 3 phases are to blame. There was trend that when the phase of the oscillation is El Nino and ENSO Neutral, February afternoon temperatures were far more erratic than when the phase is La Nina. Unfortunately, the correlation wasn’t strong enough to say that the phase of ENSO is the reason, but it’s something to investigate further.

For now, you are right in feeling like temperatures have been on a roller coaster trend this February. Compared to the last 5 years it looks like all Februarys in Raleigh are that way, but it’s not the case over the last 20 years. Here is to a hopefully smoother March!