Arctic News: Northern Hemisphere heating up

Friday, May 15, 2026

Northern Hemisphere heating up

The global surface air temperature was 15.91°C on May 13, 2026, the highest temperature on record for the time of year and 0.72°C higher than 1991-2020 (more from pre-industrial), as illustrated by the image below, adapted from Copernicus.

The Northern Hemisphere temperature was 17.56°C on May 9, 2026, the highest temperature on record for the time of year and 1.17°C higher than 1979-2000 (and even more from pre-industrial).

The Northern Hemisphere is now heating up rapidly:
• Seasonal change - temperatures typically reach a peak in July

• The Northern Hemisphere has more land, where temperatures reach higher levels in Summer

• The temperature rise is accelerating with feedbacks kicking in with greater ferocity
• We're rapidly moving from a La Niña into an El Niño

El Niño is discussed in this earlier post and illustrated by the image below, adapted from NOAA.

[ from earlier post ]

Accelerating temperature rise

The image below, from an earlier post, illustrates a potentially strongly accelerating temperature rise on land in the Northern Hemisphere in the course of 2026. Note that the anomalies in the image below are from 1901-2000 and would be higher when calculated from pre-industrial.

[ from earlier post ]

The image below uses Global Land+Ocean NASA monthly data through March 2026. Data are first adjusted from NASA's default 1951-1980 base to an earlier 30-year base, i.e. a 1886-1915 base, and then further adjusted by 0.99°C to reflect ocean air temperatures, higher polar anomalies and a pre-industral base.

[ from earlier post ]

How the 0.99°C adjustment in the above image is calculated is shown in the bright yellow inset of the image below, from an earlier post and discussed at the pre-industrial page.

[ from April 2024 post, click on images to enlarge ]

Conclusion

The situation is dire and unacceptably dangerous, and the precautionary principle necessitates rapid, comprehensive and effective action to reduce the damage and to improve the outlook, where needed in combination with a Climate Emergency Declaration, as described in posts such as in this 2022 post and this 2025 post, and as discussed in the Climate Plan group.