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State-by-State Look at How Early Spring Has Arrived

By Climate Central

For most of the country spring has sprung earlier this year, but is this anything more than a single warm year? It seems that it is. During the past several decades, with the exception of a few states, spring weather has, indeed, been arriving earlier.

In the interactive above, you can see how much earlier spring has arrived state-by-state, measured by the date of "first leaf." As you hover over any state, it'll display two boxes: a gray box that represents the day spring used to arrive (based on the 1961-1980 average) and a colored box that represents how much earlier spring has arrived in recent years (based on the 1991-2010 average).

Nationwide, the date of “first leaf” has clearly shifted — arriving roughly three days earlier now on March 17 (1991-2010 average) from March 20 (1961-1980 average). This shift affects all sorts of biological processes that are triggered by warmer temperatures — not just flowering, but animal migration and giving birth and the shedding of winter coats and the emergence from cocoons. How much will an earlier spring disrupt the intricate natural balance between the tens of thousands of species that depend on each other for food, reproduction and ultimately, survival? No one really knows.

The data behind the map comes from an index for the onset of spring developed by Mark D. Schwartz (University of Wisconsin-Milwaukee) and USA National Phenology Network colleagues. The index, based on daily minimum and maximum air temperatures measured at individual weather stations, estimates the first day that leaves appear on plants in a given state. Developed from cloned lilac and honeysuckle observations, the models are most applicable to temperature-responsive forest trees, shrubs and agricultural crops planted in temperate regions with adequate rainfall, or in temperate dry regions where irrigation is used. 

NOTE: An earlier version of this map was published on March 21. The story has been updated based on consultations with Schwartz and colleagues. They have examined trends in spring onset since 1900 across the lower 48 states, and find complex patterns of differential warming across regions, especially in the first half of the 20th century. Our updated analysis focuses after 1960 when trends show a more cohesive spatial pattern across the U.S. 

Comments

By Angela (Hutchinson, KS 67501)
on March 21st, 2012

Only 5 days early? That’s as far back as this goes? I disagree wholeheartedly. In Kansas, this time last month plants, trees and flowers were emerging and blooming. Birds had migrated back and Robins were plentiful (still are of course).  February 29th we had thunderstorms and tornadoes. We had various other spring showers prior to Feb. 29th as well.

Welcome to climate change. It is a natural life-cycle of the Earth which we are well overdue for anyway. Yes, it means much will change. Yes, it could be dangerous. No, we should not be panicking about it or fear mongering. Accept it as it is, educated yourself and then prepare. Easy as that.

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By Becky (Aurora, Colorado, 80012)
on June 9th, 2014

Sorry but while change is continual THIS type of rapid change is mathematically beyond any possibility that it is a natural occurence.  And that is important because when climate change takes 5,000 years to occur, there is time for adaption.  At the pace it is happening now, this is no time for adaptation.
There is a lot of green house gases in the atmosphere at all times.  But they cycle threw the system.  We are adding large amounts that were trapped underground and NOT part of the climatic system.  The Earth is employing (naturally) her feedback mechanism to control the effects of what we are doing but as those mechanism become overwhelmed the global warming will increase rapidly and eventually become a run-away process.  Good example, the increased acidity of the oceans from CO2 that is killing off the fish.  Eventually the ocean cannot hold anymore and starts to release it.
So this is not normal.  And no.  I am not a fear monger but I like to look at the world with open eyes.

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By Michael T in NC
on March 22nd, 2012

“Only 5 days early? That’s as far back as this goes? I disagree wholeheartedly. In Kansas, this time last month plants, trees and flowers were emerging and blooming. Birds had migrated back and Robins were plentiful (still are of course). February 29th we had thunderstorms and tornadoes. We had various other spring showers prior to Feb. 29th as well.”

Angela,

Please read the article again because I don’t think you understand what the data is saying. The data is for a 30-year average period. From the article it clearly says:

In the interactive below, you can see how much earlier spring has arrived state-by-state, measured by the date of first leaf. As you hover over any state, it’ll display two boxes: a gray box that represents the day spring used to arrive (based on the 1951-1980 average) and a colored box that represents how much earlier spring has arrived (based on the 1981-2010 average). 

So on average, spring arrived 4 days (not 5 days) earlier (March 12) during the period 1981-2010 compared to (March 16) during the 1951-1980 average for the state of Kansas.

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By dnfree (northern IL)
on March 24th, 2012

Angela believes she doesn’t need to panic because she lives in Kansas, far from any coastline.  Even if you believe that this change is completely natural and cyclical, and that having billions of people on the earth really hasn’t affected climate much, that doesn’t mean we will be able to just “accept it as it is”.  Because there are billions of people on the earth, changes in climate will have a huge effect.  Already people who live on some Pacific islands are having to be moved elsewhere.  What happens when people on the coasts of the US suddenly have to be moved elsewhere?  Who will absorb the cost?  Where will they go?  What happens if areas that used to be productive for agriculture become less so?

Angela is not going to worry about the massive drought in Texas or the severe tornadoes across the Plains states, either.  Just prepare yourselves, people.

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By David (Ohio)
on March 25th, 2012

I think it’s much worse than implied by that map.  I once came across some old phenological records from the end of the 19th Century & beginning of the 20th century, and they showed leaf out occurring in the 1st or 2nd week of May, whereas it now occurs in the second or third week of April.  So that would be a shift of about 21 days.

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By Darrell (Monroe, WA 98272)
on March 27th, 2012

Angel, you mentioned that one should “educate yourself”. Do you mean educate by the small minority who deny that pumping millions of tons of CO2 into the atmosphere has any affect or, educate by the hundreds of climate scientists who’s research supports GW?

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By Thomas Lee Boles (Saint Paul, Minnesota 55130)
on April 1st, 2012

Anybody who lives in Kansas and doesn’t worry about tornadoes is either delusional or just not paying attention. Here in Saint Paul I heard the sirens several times last year, and saw a day so dark I was surprised not to experience a twister. Last June and July were hotter than the hinges; on August 2 a very special friend died of heat stroke. Early this March we had temperatures in the upper seventies. I’m not buying any cruises on that river in Egypt.

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By Tim Remple (Longmont, CO 80503)
on May 6th, 2012

This actually understates the effect, herein Colorado this year!  If you look at eh snow pack data from http://www.wcc.nrcs.usda.gov/snow/ (Snotel) and
ftp://ftp-fc.sc.egov.usda.gov/CO/Snow/snow/watershed/daily/basinplotstate12.gif
in particular, you’ll see the average peak snow pack, statewide, is April 12.  This year, it was March 11th!!

What is wild is the VARIATION from season to season.  One effect of global warming could be increased variability of the weather!

One year lot of water, next year little.

Thought if you look at drought maps of the US ( http://droughtmonitor.unl.edu ), you’d come away thinking that Texas and Georgia are in a world of hurt, and it’s getting worse, not better! 

But it sure won’t be good for any of the West if this trend continues!!
The lack of water impact on CO, AZ, and CA could be more than enormous!!!

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