Susan Kosisky, who is the Chief Microbiologist at the US Army Centralized Allergen Extract Lab here in the D.C. area supplies the region with the daily pollen counts. So far this year, pollen counts have been well below average because of the cooler than average weather.
With temperatures in the 70s and 80s just last week from the 10th through the 15th of April, tree pollen started to spike. The highest tree pollen count of the Spring was noted on Monday at 1058 grains per cubic meter. This was short-lived though, as a strong cold front not only brought with it a few inches of rain, but also sleet, snow and cold temperatures Tuesday through today.
The count fell considerably with numbers under 100, which is still in the moderate range, but rather low compared to the average. As Kosisky put it,
"The count was predictable after the cold, rain and even snowflakes of the day before. We should be counting snowflakes instead of pollen grains this tree season! Daily average for the 3rd week in April is 953 grains/cubic meter."
- 2014 Tree Pollen vs. Avg (Credit: Susan Kosisky)
Above is a look at the average tree pollen count going into the Spring in blue and a look at what our area has experienced this year in red. There have been a few spikes, but for the most part have really been held in check.
- Largest tree pollen counts 1998-2012
From 1998 through 2012, tree pollen numbers have typically spiked in the month of April. The earliest was March 28, 2012, which also happened to be the hottest month of March on record in D.C., when it was an astounding 10 degrees above normal for the month.
It's currently the 18th of April, and our highest tree count so far is 1058, so unless this year goes down like 2000 where the highest count was slightly above 1400, we unfortunately still have a ways to go.