Here’s what 70 degree days mean to the start of spring in Charlotte

You knew of course that warmth has bathed the Carolinas since mid-January. But federal scientists have put a date on when spring blossomed in Charlotte: Instead of March 20, it’s here already more than two weeks early.

To reach that conclusion, scientists with the U.S. Geological Survey consulted data on two common flowering plants, lilacs and honeysuckle. The plants are sensitive to heat and grow leaves and flowers when enough warmth has accumulated.

The government scientists then combined bloom dates with current and long-term temperature data. That produced maps, updated daily, that show the creep of blooming plants – spring itself – from the Southeast northward.

Charlotte’s average temperature was 7.5 degrees warmer than normal in January and rose to 9.5 degrees above normal in February. We’ve seen highs of 70 degrees or warmer on 15 days already this year.

Charlotte tied for the record warmest February with an average temp of 53.4 degrees, according to the National Weather Service. This also occurred in 1927. Records go back to 1878.

The maps come from the National Phenology Network, which is part of the Geological Survey. Phenology studies the rhythyms of nature – when birds build their nests, fish swim upstream to spawn and tree leaves turn to gold in autumn.

Nature’s timing, or mistiming, is important to us and to plants and wildlife, the network says.

An early spring could bring disease-carrying ticks and mosquitoes. It can bless some crops, such as winter wheat, with more time to grow but risk late frost damage to peaches and other fruits. And it can throw off the balance between blooming wildflowers and the birds, bees and butterflies that pollinate them.

In the Southeast, scientists have found that birds are adjusting their migrations as temperatures change. Loggerhead turtles in Florida are laying their eggs 12 days earlier than they did 15 years ago. Salamanders in South Carolina began their fall breeding as much as 76 days earlier than they did three decades ago.

Other studies have shown the impact of climate change on springtime. A recent study found that spring is arriving earlier in three-quarters of the national parks, and half are seeing extremely early warmth compared to that of the previous century.

Globally, 2016 was the hottest on record, for the third year in a row. Sixteen of the 17 warmest years have been recorded since 2000.

This story was originally published March 1, 2017 at 11:53 AM with the headline "Here’s what 70 degree days mean to the start of spring in Charlotte."