Cold Winter of 2009-2010 vs. Hot Summer of 2010
We all know by now that this summer was the second warmest on record for the Charlotte area. It sure did feel like it too with the record breaking number of hours over 100° for a heat index as well.
Yet is appears we actually had a much colder winter compared to average than we had a hotter than average summer. Here’s what I mean, by looking at the Meteorological seasons of Winter, (December-January-February) and comparing it to Summer (June-July-August). I calculated the departure from average for those months. Here is the very interesting results.
Winter 2009-2010
Temperature departure from normal
December –4.5°
January –4.1°
February –6.8°
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Total -15.4°
Summer 2010
Temperature departure from normal
June +3.8°
July +1.7°
August +2.0°
—————————————————–
Total +7.5°
Take Winter –15.4°+ Summer +7.5° = –7.9° from avg.
In both cases the abnormally hot summer and abnormally cold winter weren’t so much about record temperatures per say, and by that I mean record highs and record lows. We didn’t set many record highs this summer but the overnight lows never cooled down which in turn skewed the average numbers higher. The amount of humidity just kept those overnight lows this summer in the mid-70s most of the time. This past winter we also didn’t set many record lows but the afternoon highs never climbed much with many days it never getting out of the 30s. The key to getting these very warm average temperatures was the warm overnight lows or more likely keeping the whole 24 hour period warm just not the peak heating of the day (2-5pm). Conversely this winter it wasn’t about the cold overnights but the fact that it remained cold all day long.
So even with our second hottest summer on record in Charlotte we didn’t even come close to wiping out the very cold winter we just had which was the coldest since the 1970s. The net departure from average between the 2 season is still –7.9° cooler than average. We’ll have to see what the fall will bring this year.
