Trends in record-breaking temperatures for the conterminous United States
Article first published online: 22 AUG 2012
©2012. American Geophysical Union. All Rights Reserved.
Geophysical Research Letters
Volume 39, Issue 16, August 2012
How to Cite
2012), Trends in record-breaking temperatures for the conterminous United States, Geophys. Res. Lett., 39, L16703, doi:10.1029/2012GL052775., and (
- Issue published online: 22 AUG 2012
- Article first published online: 22 AUG 2012
- Manuscript Accepted: 15 JUL 2012
- Manuscript Revised: 13 JUL 2012
- Manuscript Received: 19 JUN 2012
- climate change;
- global warming;
- temperature records
 In an unchanging climate, record-breaking temperatures are expected to decrease in frequency over time, as established records become increasingly more difficult to surpass. This inherent trend in the number of record-breaking events confounds the interpretation of actual trends in the presence of any underlying climate change. Here, a simple technique to remove the inherent trend is introduced so that any remaining trend can be examined separately for evidence of a climate change. As this technique does not use the standard definition of a broken record, our records* are differentiated by an asterisk. Results for the period 1961–2010 indicate that the number of record* low daily minimum temperatures has been significantly and steadily decreasing nearly everywhere across the United States while the number of record* high daily minimum temperatures has been predominantly increasing. Trends in record* low and record* high daily maximum temperatures are generally weaker and more spatially mixed in sign. These results are consistent with other studies examining changes expected in a warming climate.