During an El Niño event, sea-surface temperatures across an area of the Pacific Ocean as large as the United States can rise by 1–3°F or more for a few months to one or two years.
Sources
- What You Need to Know about El Niño (blog.education.nationalgeographic.com)
- https://news.ucar.edu/13308/el-nino-la-nina-enso-faq (news.ucar.edu)
- https://www.weather.gov/media/climateservices/ENSO.pdf (weather.gov)
- https://eospso.gsfc.nasa.gov/sites/default/files/publications/1998_El_Nino.pdf (eospso.gsfc.nasa.gov)
- https://weather.ou.edu/~spark/AMON/v1_n5/News/elnino/elnino.html (weather.ou.edu)