Global Temperature Report: April 2017
Global climate trend since Nov. 16, 1978: +0.12 C per decade
April temperatures (preliminary)
Global composite temp.: +0.27 C (about 0.49 degrees Fahrenheit) above 30-year average for April.
Northern Hemisphere: +0.27 C (about 0.49 degrees Fahrenheit) above 30-year average for April.
Southern Hemisphere: +0.26 C (about 0.47 degrees Fahrenheit) above 30-year average for April.
Tropics: +0.21 C (about 0.38 degrees Fahrenheit) above 30-year average for April.
March temperatures (revised):
Global Composite: +0.19 C above 30-year average
Northern Hemisphere: +0.30 C above 30-year average
Southern Hemisphere: +0.07 C above 30-year average
Tropics: +0.03 C above 30-year average
(All temperature anomalies are based on a 30-year average (1981-2010) for the month reported.)
Notes on data released May 2, 2017:
Compared to seasonal norms, the coldest place on Earth in April was off the eastern coast of the Antarctic Peninsula in Weddell Sea. Temperatures there averaged 4.24 C (about 7.63 degrees Fahrenheit) colder than seasonal norms.
Compared to seasonal norms, the warmest place on Earth in April was off the east coast of Wrangel Island in the Chukchi Sea, north of the Bering Strait between Siberia and Alaska. Temperatures there averaged 3.96 C (about 7.13 degrees Fahrenheit) warmer than seasonal norms.
As part of an ongoing joint project between UAH, NOAA and NASA, Dr. John Christy, director of the Earth System Science Center at The University of Alabama in Huntsville, and Dr. Roy Spencer, an ESSC principal scientist, use data gathered by advanced microwave sounding units on NOAA and NASA satellites to get accurate temperature readings for almost all regions of the Earth. This includes remote desert, ocean and rain forest areas where reliable climate data are not otherwise available.
The satellite-based instruments measure the temperature of the atmosphere from the surface up to an altitude of about eight kilometers above sea level. Once the monthly temperature data are collected and processed, they are placed in a "public" computer file for immediate access by atmospheric scientists in the U.S. and abroad.. Temperatures in the tropics are essentially “normal” relative to the 30-year average.
Compared to seasonal norms, the warmest spot on the globe in March was over eastern Russia, near the city of Yakutsk, with an average temperature that was 5.58 C (about 10.04 degrees Fahrenheit) warmer than seasonal norms.
Compared to seasonal norms, the coolest average temperature on Earth in March was over eastern Alaska near Dot Lake Village. March temperatures there averaged 4.08 C (about 7.34 degrees F) cooler than seasonal norms.
The complete version 6 lower troposphere dataset is available here:
Archived color maps of local temperature anomalies are available on-line at:
Neither Christy nor Spencer receives any research support or funding from oil, coal or industrial companies or organizations, or from any private or special interest groups. All of their climate research funding comes from federal and state grants or contracts.