Average pollen levels (yellow) compared to observed pollen levels during 2010 (blue) and 2011 (red) thus far for Washington D.C. region. (U.S. Army Centralized Allergen Extract Lab, Walter Reed Army Medical Center)

What it tells us is that the worst tree pollen days are still to come if the past is any indicator of the future.

Whereas the current tree pollen season started fast and furious following late February and mid-March warmth, it mercifully dropped during the cold, damp weather in late March.

But the levels it reached in 2010 tower over what we’ve experienced so far (for comparison, yesterday’s count for trees was 136.1 grams per cubic meter compared to the maximum value over 1800 reached last year) and the historic (average) seasonal peak is still weeks away.

Keep the antihistamines handy...