<!DOCTYPE html PUBLIC "-//W3C//DTD HTML+RDFa 1.1//EN">




<html class="no-js not-oldie" lang="en" dir="ltr" version="HTML+RDFa 1.1">
  <meta charset="utf-8" />

<link rel="shortcut icon" href="/sites/all/themes/epa/favicon.ico" type="image/vnd.microsoft.icon" />
<meta name="HandheldFriendly" content="true" />
<meta name="viewport" content="width=device-width" />
<meta name="MobileOptimized" content="width" />
<meta http-equiv="ImageToolbar" content="false" />
<meta http-equiv="cleartype" content="on" />


<meta name="keywords" content="climate change; global warming; science; indicator; data; snow; ice;" />
<link rel="canonical" href="/climate-indicators/snow-ice" />
<link rel="shortlink" href="/climate-indicators/snow-ice" />







<meta name="WebArea" content="Climate Change Indicators" />
<meta name="WebAreaType" content="Microsite" />
<meta name="ContentType" content="page" />
  <title>Climate Change Indicators: Snow and Ice | Climate Change Indicators in the United States | US EPA</title>
  
  <link type="text/css" rel="stylesheet" href="/sites/production/files/css/css_3h5HfPyG4w0xmgk_oaLP90_rUIs7Xmed0sNIfCxGAyg.css" media="all" />
<link type="text/css" rel="stylesheet" href="/sites/production/files/css/css_NFNG4tEiKv-n_hlnQ4iBNlFbb-9XRaRVA9wRk6nUPHY.css" media="all" />
<link type="text/css" rel="stylesheet" href="/sites/production/files/css/css_Pvo-DHIdW2Qn9LljtH2R1QKqzm8QoJ18zl6wR9Dk-Ak.css" media="all" />
<link type="text/css" rel="stylesheet" href="/sites/production/files/css/css_28CvFue6tf4M8aL9zid2j2W58Z6HleySMQyNH35QhI0.css" media="all" />

<!--[if lt IE 9]>
<link type="text/css" rel="stylesheet" href="/sites/production/files/css/css_H7Qs31C_4pOAKdUe1sAA01nOyZTqO_KOIt1uDr0iKB4.css" media="all" />
<![endif]-->
<link type="text/css" rel="stylesheet" href="/sites/production/files/css/css_68w49Vk1SYPj8EPx2iW8fUagDJ4xc2WJQO7Dn7aLNaU.css" media="all" />
  <link rel="alternate" type="application/atom+xml" title="EPA.gov All Press Releases" href="/newsreleases/search/rss" />
  <link rel="alternate" type="application/atom+xml" title="EPA.gov Headquarters Press Releases" href="/newsreleases/search/rss/field_press_office/headquarters" />
  <link rel="alternate" type="application/atom+xml" title="Greenversations, EPA's Blog" href="https://blog.epa.gov/blog/feed/" />
  <link rel="alternate" type="application/atom+xml" title="Climate Change Indicators" href="/feed/125251/rss.xml" />    </head>
<body class="html not-front not-logged-in one-sidebar sidebar-first page-node page-node-153987 node-type-page og-context og-context-node og-context-node-125251 section-climate-indicators microsite" >
  <div class="skip-links"><a href="#main-content" class="skip-link element-invisible element-focusable">Jump to main content</a></div>
      
  
  <div class="region-alert">  <div id="block-pane-epa-admin-public-alert-message" class="block block-pane  block-pane-epa-admin-public-alert-message block-alert">
  
  
  
  
      
</div>
<div id="block-pane-epa-gtm" class="block block-pane  block-pane-epa-gtm">
  
  
  
  
    

  
</div>
  </div>
<div id="brand-header"></div>
<header class="masthead clearfix" role="banner">

      <img class="site-logo" src="/sites/all/themes/epa/logo.png" alt="" />
  
  
  <hgroup class="site-name-and-slogan">
      <h1 class="site-name">

      
      <a href="/" title="Go to the home page" rel="home">      <span>US EPA</span>
      </a>
    </h1>
  
      <div class="site-slogan">United States Environmental Protection Agency</div>
  
  </hgroup>
  
  

</header>
<div id="brand-menu"></div>
<section id="main-content" class="main-content clearfix" role="main" lang="en">
  <h2 class="microsite-name">Climate Change Indicators</h2>  
  
  <div class="region-preface clearfix">   
 
  </div>
    <div class="main-column clearfix">
            
          
      <h1  class="page-title">Climate Change Indicators: Snow and Ice</h1>
      
    
            
    
    
    
  
    




<div class="panel-pane pane-node-content" >

  
  
  
  
  
  <div class="pane-content">
    <div class="node node-page clearfix view-mode-full ">

  
  <div class="box multi related-info right">
	<h2>View Indicators:</h2>

	<div><a href="/climate-indicators/climate-change-indicators-arctic-sea-ice"><span
    class="figure image file file-image file-image-png view-mode-full" style="width:320px;"><img alt="Arctic Sea Ice" height="260" width="320" class="media-element file-full" typeof="foaf:Image" src="/sites/production/files/styles/large/public/2016-07/arctic-sea-ice-landing-thumb-2016.png" /></span></a></div>

	<div><a href="/climate-indicators/climate-change-indicators-antarctic-sea-ice"><span
    class="figure image file file-image file-image-png view-mode-full" style="width:320px;"><img alt="Antarctic Sea Ice" height="260" width="320" class="media-element file-full" typeof="foaf:Image" src="/sites/production/files/styles/large/public/2016-07/antarctic-sea-ice-landing-thumb-2016.png" /></span></a></div>

	<div><a href="/climate-indicators/climate-change-indicators-glaciers"><span
    class="figure image file file-image file-image-png view-mode-full" style="width:320px;"><img alt="Glaciers" height="260" width="320" class="media-element file-full" typeof="foaf:Image" src="/sites/production/files/styles/large/public/2016-07/glaciers-landing-thumb-2016.png" /></span></a></div>

	<div><a href="/climate-indicators/climate-change-indicators-lake-ice"><span
    class="figure image file file-image file-image-png view-mode-full" style="width:320px;"><img alt="Lake Ice" height="260" width="320" class="media-element file-full" typeof="foaf:Image" src="/sites/production/files/styles/large/public/2016-07/lake-ice-landing-thumb-2016.png" /></span></a></div>

	<div><a href="/climate-indicators/climate-change-indicators-snowfall"><span
    class="figure image file file-image file-image-png view-mode-full" style="width:320px;"><img alt="Snowfall" height="260" width="320" class="media-element file-full" typeof="foaf:Image" src="/sites/production/files/styles/large/public/2016-07/snowfall-landing-thumb-2016.png" /></span></a></div>

	<div><a href="/climate-indicators/climate-change-indicators-snow-cover"><span
    class="figure image file file-image file-image-png view-mode-full" style="width:320px;"><img alt="Snow Cover" height="260" width="320" class="media-element file-full" typeof="foaf:Image" src="/sites/production/files/styles/large/public/2016-07/snow-cover-landing-thumb-2016.png" /></span></a></div>

	<div><a href="/climate-indicators/climate-change-indicators-snowpack"><span
    class="figure image file file-image file-image-png view-mode-full" style="width:320px;"><img alt="Snowpack" height="260" width="320" class="media-element file-full" typeof="foaf:Image" src="/sites/production/files/styles/large/public/2016-07/snowpack-landing-thumb-2016.png" /></span></a></div>

	<h2>Community Connection:</h2>

	<div><a href="/climate-indicators/alaskan-rivers"><span
    class="figure image file file-image file-image-png view-mode-full" style="width:320px;"><img alt="Ice Breakup in Two Alaskan Rivers" height="260" width="320" class="media-element file-full" typeof="foaf:Image" src="/sites/production/files/styles/large/public/2016-07/river-ice-landing-thumb-2016.png" /></span></a></div>
</div>

<p>The Earth’s surface contains many forms of snow and ice, including sea, lake, and river ice; snow cover; glaciers, ice caps, and ice sheets; and frozen ground. Climate change can dramatically alter the Earth’s snow- and ice-covered areas because snow and ice can easily change between solid and liquid states in response to relatively minor changes in temperature. This chapter focuses on trends in snow, glaciers, and the freezing and thawing of oceans and lakes.</p>

<ul class="accordion"><li><a class="accordion-title" href="#pane-1" title="Click to expand description">Why does it matter?</a>

		<div class="accordion-pane" id="pane-1">
			<p>Reduced snowfall and less snow cover on the ground could diminish the beneficial insulating effects of snow for vegetation and wildlife, while also affecting water supplies, transportation, cultural practices, travel, and recreation for millions of people. For communities in Arctic regions, reduced sea ice could increase coastal erosion and exposure to storms, threatening homes and property, while thawing ground could damage roads and buildings and accelerate erosion. Conversely, reduced snow and ice could present commercial opportunities for others, including ice-free shipping lanes and increased access to natural resources.</p>

			<p>Such changing climate conditions can have worldwide implications because snow and ice influence air temperatures, sea level, ocean currents, and storm patterns. For example, melting ice sheets on Greenland and Antarctica add fresh water to the ocean, increasing sea level and possibly changing ocean circulation that is driven by differences in temperature and salinity. Because of their light color, snow and ice also reflect more sunlight than open water or bare ground, so a reduction in snow cover and ice causes the Earth’s surface to absorb more energy from the sun and become warmer.</p>
		</div>
	</li>
</ul><h3>Summary of Key Points</h3>

<ul class="roomy"><li><strong><a href="/climate-indicators/climate-change-indicators-arctic-sea-ice_.html">Arctic Sea Ice</a>.</strong> Part of the Arctic Ocean is covered by ice year-round. The area covered by ice is typically smallest in September, after the summer melting season. The annual minimum extent of Arctic sea ice has decreased over time, and in September 2012 it was the smallest ever recorded. The length of the melt season for Arctic ice has grown, and the ice has also become thinner, which makes it more vulnerable to further melting.</li>
	<li><strong><a href="/climate-indicators/climate-change-indicators-antarctic-sea-ice">Antarctic Sea Ice</a>.</strong> Antarctic sea ice extent in September and February has increased somewhat over time. The September maximum extent reached the highest level on record in 2014—about 7 percent larger than the 1981­–2010 average. Slight increases in Antarctic sea ice are outweighed by the loss of sea ice in the Arctic during the same time period, however.</li>
	<li><strong><a href="/climate-indicators/climate-change-indicators-glaciers">Glaciers</a>.</strong> Glaciers in the United States and around the world have generally shrunk since the 1960s, and the rate at which glaciers are melting has accelerated over the last decade. The loss of ice from glaciers has contributed to the observed rise in sea level. </li>
	<li><strong><a href="/climate-indicators/climate-change-indicators-lake-ice">Lake Ice</a>.</strong> Lakes in the northern United States are freezing later and thawing earlier compared with the 1800s and early 1900s. Freeze dates have shifted later at a rate of roughly half a day to one-and-a-half days per decade. All of the lakes studied were also found to be thawing earlier in the year, with spring thaw dates growing earlier by up to 24 days in the past 110 years.
		<ul><li><strong><a href="/climate-indicators/alaskan-rivers">Community Connection: Ice Breakup in Two Alaskan Rivers</a>. </strong>Regions in the far north are warming more quickly than other parts of the world. Two long-running contests on the Tanana and Yukon rivers in Alaska—where people guess the date when the river ice will break up in the spring—provide a century’s worth of evidence revealing that the ice on these rivers is generally breaking up earlier in the spring than it once did.</li>
		</ul></li>
	<li><strong><a href="/climate-indicators/climate-change-indicators-snowfall">Snowfall</a>.</strong> Total snowfall—the amount of snow that falls in a particular location—has decreased in most parts of the country since widespread records began in 1930. One reason for this decline is that nearly 80 percent of the locations studied have seen more winter precipitation fall in the form of rain instead of snow.</li>
	<li><strong><a href="/climate-indicators/climate-change-indicators-snow-cover">Snow Cover</a>.</strong> Snow cover refers to the area of land that is covered by snow at any given time. Between 1972 and 2015, the average portion of North America covered by snow decreased at a rate of about 3,300 square miles per year, based on weekly measurements taken throughout the year. There has been much year-to-year variability, however. The length of time when snow covers the ground has become shorter by nearly two weeks since 1972, on average.</li>
	<li><strong><a href="/climate-indicators/climate-change-indicators-snowpack">Snowpack</a>.</strong> The depth of snow on the ground (snowpack) in early spring decreased at more than 90 percent of measurement sites in the western United States between 1955 and 2016. Across all sites, snowpack depth declined by an average of 23 percent during this time period.</li>
</ul><p class="pagetop"><a href="#main-content">Top of Page</a></p>
</div>
  </div>

  
  
</div>



<div id="block-pane-epa-web-area-footer" class="block block-pane  block-pane-epa-web-area-footer">
  
  
  
  
    
</div>
  
    
      </div>
  
  
  <div class="region-sidebar-first region-sidebar">  <div id="block-og-menu-og-single-menu-block" class="block block-og-menu  block-og-menu-og-single-menu-block">

      <h2 class="element-invisible">Climate Indicators</h2>
  
  
    <ul class="menu"><li class="menu-item"><a href="/climate-indicators" title="" class="menu-node-unpublished menu-link">Climate Change Indicators</a></li>
<li class="menu-item"><a href="/climate-indicators/greenhouse-gases" class="menu-node-unpublished menu-link">Greenhouse Gases</a></li>
<li class="menu-item"><a href="/climate-indicators/weather-climate" class="menu-node-unpublished menu-link">Weather and Climate</a></li>
<li class="menu-item"><a href="/climate-indicators/oceans" class="menu-node-unpublished menu-link">Oceans</a></li>
<li class="active-trail menu-item"><a href="/climate-indicators/snow-ice" class="menu-node-unpublished active-trail menu-link active">Snow and Ice</a><ul class="menu"><li class="menu-item"><a href="/climate-indicators/climate-change-indicators-arctic-sea-ice" class="menu-node-unpublished menu-link">Arctic Sea Ice</a></li>
<li class="menu-item"><a href="/climate-indicators/climate-change-indicators-antarctic-sea-ice" class="menu-node-unpublished menu-link">Antarctic Sea Ice</a></li>
<li class="menu-item"><a href="/climate-indicators/climate-change-indicators-glaciers" class="menu-node-unpublished menu-link">Glaciers</a></li>
<li class="menu-item"><a href="/climate-indicators/climate-change-indicators-lake-ice" class="menu-node-unpublished menu-link">Lake Ice</a></li>
<li class="menu-item"><a href="/climate-indicators/alaskan-rivers" class="menu-node-unpublished menu-link">Community Connection: Ice Breakup in Two Alaskan Rivers</a></li>
<li class="menu-item"><a href="/climate-indicators/climate-change-indicators-snowfall" class="menu-node-unpublished menu-link">Snowfall</a></li>
<li class="menu-item"><a href="/climate-indicators/climate-change-indicators-snow-cover" class="menu-node-unpublished menu-link">Snow Cover</a></li>
<li class="menu-item"><a href="/climate-indicators/climate-change-indicators-snowpack" class="menu-node-unpublished menu-link">Snowpack</a></li>
</ul></li>
<li class="menu-item"><a href="/climate-indicators/health-society" class="menu-node-unpublished menu-link">Health and Society</a></li>
<li class="menu-item"><a href="/climate-indicators/ecosystems" class="menu-node-unpublished menu-link">Ecosystems</a></li>
<li class="menu-item"><a href="/climate-indicators/frequent-questions-about-climate-change-indicators" class="menu-node-unpublished menu-link">Frequent Questions</a></li>
</ul>  
</div>
  </div>
</section>




 
  <div id="brand-footer"></div>
 <script type="text/javascript" src="/sites/production/files/js/js_LcFRnnSHVah-Aw_WQ8aVLXhp3HPJvrOe4h6YEXA5BT8.js"></script>
<script type="text/javascript" src="/sites/production/files/js/js_oZD9-WvfiElJ5KPavqu9ZAQiZcfWlzNCzxFHpedR9dI.js"></script>

<script type="text/javascript" src="/sites/production/files/js/js_slEmfY49PYt03JJafrjvmxmEfVQE7vqI-454V7NM5ys.js"></script>
<script type="text/javascript" src="/sites/all/modules/custom/epa_core/js/alert.js?ok0rem"></script>
<script type="text/javascript" src="/sites/production/files/js/js_cjmkhjdYj9qyv8rH-ylGyD-SIMacZ-dzdqW9m8x_TEc.js"></script>

<script type="text/javascript" src="/sites/production/files/js/js_UG00nMwTXcewn_yu8c3s7Bgbxmhbdk0BE1GwQLAuoQU.js"></script>
<script type="text/javascript" src="/sites/production/files/js/js_CaVFOiO3QpcJYEzSDhR3RmEeSnMbgnImgh5uEDkDD_0.js"></script>

<style>
img {
margin-bottom:0 !important;
}
</style>    </body>
</html>

