U.S. Heat February 2017

The analysis finds that February 2017 was the second warmest February on record for the contiguous United States, with temperatures 3.1°C above the 1981–2010 normal. By combining historical observations with CMIP5, HadGEM3-A, and Weather@Home model ensembles, the study concludes that the probability of such a warm event has increased more than threefold due to human-induced greenhouse gas emissions. While the 2017 event had a return period of approximately 12 years in the current climate, it would have been a 1-in-160-year event around 1900. Projections suggest that by 2050, temperatures like those seen in February 2017 will be 'completely normal', occurring roughly every three years.

• February 2017 was the second warmest February on record for the contiguous United States (CONUS), with a temperature of 4.9 °C, which was 3.1°C warmer than the 1981–2010 normal. It was the warmest February on record for the area east of the Rocky Mountains.
• The frequency of record-breaking high temperatures was extreme in February 2017, with over 6,300 record daily highs tied or broken compared to fewer than 130 record lows, resulting in a ratio of 49 high records for every one low record.
• Observational data indicates that the likelihood of a February as warm as 2017 has increased significantly since 1900; the return period has shifted from approximately 160 years (0.6% annual probability) around 1900 to about 12 years (8% annual probability) in the current climate.
• A weighted average of observational trends and three model ensembles (CMIP5, HadGEM3-A, and Weather@Home) concludes that human-caused climate change has increased the probability of such warm February events by more than a factor of three.
• Climate model simulations indicate that without human-induced increases in greenhouse gases, the return period for a February as warm as 2017 would be approximately 60 years, compared to the current 18-year return period estimated by CMIP5 models.
• Projections for the year 2050, based on the RCP8.5 scenario of continued intensive fossil fuel use, suggest that temperatures similar to February 2017 will occur on average every three years.
• While the overall trend is toward warming, the study notes that natural weather fluctuations will continue to produce cold events, although their probability is reduced.

APA

World Weather Attribution (2017). U.S. Heat February 2017. https://www.worldweatherattribution.org/u-s-heat-february-2017/

Chicago

World Weather Attribution. U.S. Heat February 2017. 2017. https://www.worldweatherattribution.org/u-s-heat-february-2017/.

Wikipedia

{{cite report |author=World Weather Attribution |title=U.S. Heat February 2017 |date=8 March 2017 |url=https://www.worldweatherattribution.org/u-s-heat-february-2017/ |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{worldweatherattribution2017heat, author = {{World Weather Attribution}}, title = {{U.S. Heat February 2017}}, institution = {World Weather Attribution}, year = {2017}, month = mar, url = {https://www.worldweatherattribution.org/u-s-heat-february-2017/}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }