Amid all of the improbable points of spring, tree pollen is the microscopic bully that usually makes life depressing for allergy victims. This yr, abnormally heat climate has boosted common tree pollen counts to near-record ranges within the D.C. space.The counts have already climbed into the excessive vary on eight days this yr. Up to now, the height day by day rely was 1,171 pollen grains per cubic meter of air measured in early March. However that quantity will in all probability be surpassed within the days and weeks forward.Spring has woke up unusually early this yr, with Washington’s common temperature the sixth-warmest on report yr so far. Plant and tree life, together with the famed cherry blossoms on the Tidal Basin, are rushing into spring mode.Spring’s early arrival and the quick begin to allergy season have turn into widespread lately due to rising temperatures pushed by human-caused local weather change.The primary tree pollen grains of 2024 had been counted lower than 10 days into the yr. By late January, counts had been above common and climbing. Apart from a slowdown or two throughout short-lived chilly spells, pollen season has roared to life in late winter — a typical theme lately.Average tree pollen ranges had been first noticed Feb. 8, a few week sooner than the norm; Feb. 22 marked the primary high-pollen day. A pollen rely of no less than 15 grains per cubic meter of air is taken into account reasonable; excessive begins at 90 grains.Through the fourth week of February, the common rely was 522 grains in contrast with a median of 75, Susan Kosisky, director of aerobiological reporting and analysis on the U.S. Military Centralized Allergen Extract Lab, mentioned in an e mail.February’s last week and the primary week of March each had the second-highest common counts on report, Kosisky mentioned.There has but to be a rely over 1,500 grains this yr, which is taken into account “very excessive,” however the common first date of this — on April 8 — has been shifting up lately. In yearly since 2020, it has occurred earlier than this date.Final yr, the primary very excessive rely occurred Feb. 23 — the earliest on report — whereas it was March 6 the yr earlier than.Most of this early blooming is tied to temperature, particularly in winter and early spring. It was so delicate this yr that some tree species didn’t go absolutely dormant as they’re meant.This winter season noticed the fewest in a single day freezes on report, whereas each month from December to February was 2 to 4 levels hotter than regular. In late January, the temperature surged to a report 80 levels, and February noticed highs within the 60s on 5 days.“A string of very heat days (60s to 70s particularly) will trigger the bushes to stir and launch their pollen as early as mid-January in our area,” Kosisky mentioned.Washington’s common temperature has risen about 0.3 levels per decade since 1900 through the winter and solely barely much less rapidly in March.Each the rise in temperatures and growing ranges of carbon dioxide within the environment from the burning of fossil fuels can improve pollen ranges. A research printed in 2020 discovered that pollen season has expanded by a number of weeks and elevated by double-digit percentages for the reason that late 1900s all through North America.Lots extra pollen to comeThe common date for peak tree pollen within the Washington area is April 14, or nonetheless a few month off.Final yr, regardless of a really heat winter and a significant pollen spike in late February, the height occurred April 13; completely different tree species launch their pollen at completely different occasions, and there may be a number of peaks some years. From 2020 to 2022, the height had already occurred by now. When there’s a peak early within the season, typically there’s much less pollen in a while, as bushes solely have a lot to expel.“Typically, if we’ve a excessive manufacturing of tree pollen in March, April will certainly be decrease,” Kosisky mentioned.After a significant explosion of pollen through the warmest March on report in 2012, counts remained on the decrease aspect for the remainder of the season, Kosisky mentioned.The common peak worth is 2,516 grains, or about twice as excessive as this yr’s peak up to now. Final yr, the worth topped out at 3,319 grains. The height has surpassed 4,000 twice prior to now twenty years; it reached 4,539 grains April 25, 2009, and 4,147 grains April 6, 2010.It’s too quickly to know whether or not the quick begin to this yr and a attainable early peak will imply a tamer second half of the season — usually tree pollen tends to fade by early Could.“Forecasting future pollen counts for the season is a problem because of the variability from yr to yr (and week to week) in temperatures, relative humidity and precipitation,” Kosisky mentioned. “Tree species can also have inherent biking patterns the place there are on and off years for greater quantities of pollen which can be launched.”