Looking back at our outlook released in May and how it compared to reality, we did well.
We correctly predicted a hot summer, though we somewhat underestimated the intensity of the heat. It turned out to be D.C.’s third-hottest summer on record.
We predicted that the summer’s average temperature would be about 2 degrees above average and were pretty close. This summer finished at 2.8 degrees above average.
We also made pretty good month-to-month temperature forecasts. We correctly predicted that as summer progressed, the temperature difference from average would increase with each passing month.
We started off on the money, correctly predicting June would finish 1 degree warmer than normal.
We were then on the right track in our temperature outlooks for both July and August despite underestimating the magnitude of the heat.
We said July would be 1 to 2 degrees warmer than average, and it was 2.9 degrees warmer than normal. August would be the warmest summer month with respect to average, we said, and that was correct. However, it finished a toasty 4.6 degrees above average compared to our call of 3 degrees above average.
Although we place less emphasis on precipitation compared to temperature in our outlook, we got it right. We predicted slightly below normal precipitation, and the actual total was 90 percent of normal.
Finally, we offered a few miscellaneous predictions, which were reasonably good but not perfect:
- We predicted one to two 100-degree days and we had four.
- We ended up with 51 90-degree days (June through August) versus our prediction of 40-45. I’d call that prediction good, not great, as we correctly identified that we’d have more 90-degree days than our normal 31, but came up a bit shy.
- Additionally, we called for a 90-degree streak of 10 days and we had an impressive streak of 13 days at the end of July into early August, so just longer than our prediction.
Considering all of the elements of our summer outlook and how it compared to reality, I would grade our outlook an A-/B+.
We were within a degree of nailing the summer average temperature, which is the aspect of the outlook we place the most emphasis on.
Regarding the monthly breakdowns, June was a bull’s eye, while July and August were good calls despite slightly underdoing the incredible heat.
We’ve had a good run with the past several summer outlooks — correctly capturing the essence of the season the past five years (we’ve graded our outlooks B or higher since 2012).
We look forward to issuing our winter outlook shortly. In the meantime, enjoy the continuation of this ideal autumn weather.