Wash. Me. Mont. N.D. Minn. Vt. Ore. N.H. Idaho Wis. N.Y. S.D. Mich. Conn. Wyo. Pa. N.J. Iowa Neb. Nev. Ohio Ind. Ill. Utah W.Va. Colo. Calif. Va. Kan. Mo. Ky. N.C. Tenn. Okla. Ariz. Ark. N.M. S.C. Ga. Ala. Miss. Tex. La. Fla. SPRING FOLIAGE Days early, against 30-year average 5 15 25 Wash. Me. Mont. N.D. Minn. Vt. Ore. N.H. Idaho Wis. N.Y. S.D. Mich. Wyo. Pa. N.J. Iowa Neb. Nev. Ohio Ind. Ill. Utah W.Va. Colo. Calif. Va. Kan. Mo. Ky. N.C. Tenn. Okla. Ariz. Ark. N.M. S.C. Ga. Ala. Miss. Tex. La. SPRING FOLIAGE Fla. Days early, against 30-year average 5 15 25 Wash. Me. Mont. N.D. Minn. Ore. Idaho Wis. N.Y. S.D. Mich. Wyo. Pa. Iowa Neb. Nev. Ohio Ind. Ill. Utah Colo. Calif. Va. Kan. Mo. Ky. N.C. Tenn. Okla. Ariz. Ark. N.M. S.C. Ga. Ala. Miss. Tex. La. Fla. SPRING FOLIAGE Days early, against 30-year average 5 15 25 SPRING FOLIAGE Days early, against 30-year average 5 15 25

By the 2017 calendar, the first day of spring is March 20. But spring leaves arrived in mid-January in some parts of the South, and spread northward like a wave. The map above plots the date of “first leaf,” a temperature-based calculation of when vegetation that has been dormant starts to show signs of life. This year, with the exception of a few small areas, the wave has arrived much earlier than the 30-year average.

An early spring means more than just earlier blooms of fruit trees and decorative shrubs like azaleas. It can wreak havoc on schedules that farmers follow for planting and that tourism officials follow for events that are tied to a natural activity like trees blooming. Some plant species that bud early may be susceptible to a snap frost later, and early growth of grasses and other vegetation can disrupt some animals’ usual cycles of spring feeding and growth.

First leaf can vary greatly from year to year and location to location, but the general long-term trend is toward earlier springs.

End of January End of February Wash. Wash. Me. Me. Mont. Mont. N.D. N.D. Minn. Minn. Ore. Ore. Idaho Idaho Wis. Wis. N.Y. N.Y. S.D. S.D. Mich. Mich. Wyo. Wyo. Pa. Pa. Iowa Iowa Neb. Neb. Nev. Nev. Ohio Ohio Ind. Ind. Ill. Ill. Utah Utah Colo. Colo. Calif. Calif. Va. Va. Kan. Kan. Mo. This year Ky. N.C. N.C. Tenn. Tenn. Okla. Okla. Ariz. Ariz. Ark. Ark. N.M. N.M. S.C. S.C. 30-year average This year Tex. Tex. La. La. Fla. Fla. FIRST LEAF INDEX 30-year average Extent of spring leaves, by month The New York Times End of January End of February Wash. Wash. Me. Me. Mont. Mont. N.D. N.D. Minn. Minn. Ore. Ore. Idaho Idaho Wis. Wis. N.Y. N.Y. S.D. S.D. Mich. Mich. Wyo. Wyo. Pa. Pa. Iowa Iowa Neb. Neb. Nev. Nev. Ohio Ohio Ill. Ill. Utah Utah Colo. Colo. Calif. Calif. Va. Va. Kan. Kan. Mo. This year Ky. N.C. N.C. Okla. Okla. Ariz. Ariz. Ark. Ark. N.M. N.M. S.C. S.C. 30-year average This year Tex. Tex. La. La. Fla. Fla. 30-year average FIRST LEAF INDEX Extent of spring leaves, by month The New York Times End of January Wash. Me. Mont. N.D. Minn. Ore. Idaho Wis. N.Y. S.D. Mich. Wyo. Pa. Iowa Neb. Nev. Ohio Ind. Ill. Utah Colo. Calif. Va. Kan. Mo. Ky. N.C. Tenn. Okla. Ariz. Ark. N.M. S.C. This year Tex. La. Fla. 30-year average End of February Wash. Me. Mont. N.D. Minn. Ore. Idaho Wis. N.Y. S.D. Mich. Wyo. Pa. Iowa Neb. Nev. Ohio Ind. Ill. Utah Colo. Calif. Va. Kan. This year N.C. Tenn. Okla. Ariz. Ark. N.M. S.C. 30-year average Tex. La. Fla. FIRST LEAF INDEX Extent of spring leaves, by month The New York Times End of January This year 30-year average End of February This year 30-year average FIRST LEAF INDEX Extent of spring leaves, by month The New York Times

The new research shows a strong link between global warming and the very warm February that helped to drive the extremely early spring this year. For the entire continental United States, February 2017 was the second warmest on record, and mean temperatures were especially high east of the Rockies: as much as 11 degrees Fahrenheit above normal.