United States

Explore historical and projected climate data, climate data by sector, impacts, key vulnerabilities and what adaptation measures are being taken. Explore the overview for a general context of how climate change is affecting United States.

Country Summary

This page presents high-level information for United States's climate zones and its seasonal cycle for mean temperature and precipitation for the latest climatology, 1991-2020. Climate zone classifications are derived from the Köppen-Geiger climate classification system, which divides climates into five main climate groups divided based on seasonal precipitation and temperature patterns. The five main groups are A (tropical), B (dry), C (temperate), D (continental), and E (polar). All climates except for those in the E group are assigned a seasonal precipitation sub-group (second letter).  Climate classifications are identified by hovering your mouse over the legend. A narrative overview of United States's country context and climate is provided following the visualizations.

Köppen-Geiger Climate Classification, 1991-2020
  • Af
  • Am
  • As/Aw
  • BWh
  • BWk
  • BSh
  • BSk
  • Csa
  • Csb
  • Csc
  • Cwa
  • Cwb
  • Cwc
  • Cfa
  • Cfb
  • Cfc
  • Dsa
  • Dsb
  • Dsc
  • Dsd
  • Dwa
  • Dwb
  • Dwc
  • Dwd
  • Dfa
  • Dfb
  • Dfc
  • Dfd
  • ET
  • EF

The United States is located in North America, bordering both the North Atlantic Ocean and the North Pacific Ocean, between Canada and Mexico. It has a total land area of 9,147,593 km2 of which 44.5% is agricultural and 33.3% is forests. The US has a population of 329,256,465 of which 82% live in urban areas. Until 2014, the US economy stood as the largest in the world in terms of GDP (PPP). In 2017, US had a GDP (PPP) of $19.49 trillion, to which services contributed 80%, industry 19.1% and agriculture 0.9%. According to the latest US National Climate Assessment (2018), U.S. average temperature has increased by 1.3°F to 1.9°F since 1895; most of this increase has occurred since about 1970. Sectors most affected by climate changes include agriculture, water, human health, energy, transportation, forests, and ecosystems. Vulnerability to climate change is exacerbated by other stresses such as pollution, habitat, fragmentation, and poverty. Although substantial adaptation planning is occurring in the public and private sectors and at all levels of government, few measures have been implemented and those that have appear to be incremental changes. Barriers to implementation of adaptation include limited funding, policy and legal impediments, and difficulty in anticipating climate-related changes at local scales.