"Meteorological Spring," which is derived from average temperature cycles over the course of three months, began on March 1st. "Astronomical Spring," which is based on the Vernal Equinox, occurring when the sun shines directly on the equator and the length of day and night is nearly equal, will begin on Thursday, March 19th.
But according to Climate Central, looking back over the past few decades, spring is arriving earlier nationally due to #climatechange. Tracking the dates when first blooms occur following winter's thaw, referred to as "leaf out," their analysis found that since 1981, spring's "leaf out is happening earlier in 76% (181) of the 239 cities" they analyzed across the U.S.
#Health consequences of an earlier spring include potentially longer and stronger #allergy seasons, and an increased window of opportunity for mosquitoes and ticks to transmit #infectious pathogens to humans.
The Asthma Allergy and Asthma Foundation of America reports that pollen season is already starting earlier and ending later than previous seasons: "Between 1995 and 2011, warmer temperatures in the U.S. have caused the pollen season to be 11 to 27 days longer. These warmer temperatures create more pollen in the air, stronger airborne allergens and more allergy symptoms."
According to the CDC, "illnesses from mosquito, tick, and flea bites have tripled in the U.S., with more than 640,000 cases reported during the 13 years from 2004 through 2016."