“Imagine the same synoptic weather patterns occurred in a warmer world. How would our experience of the weather be different? Would it be warmer? Yes. Would it be wetter? Only on the wettest 10% of days,” highlights Professor Ed Hawkins, climate scientist at the National Centre for Atmospheric Science and University of Reading.

Climate scientists are now replaying the past to predict the future, to show how everyday weather could feel in a warmer world.

A research team is taking an unusual approach to understanding the impacts of global warming on weather. Researchers have recreated real weather from the past in computer models, and then “warmed it up” to see how it could change.

Using historical pressure observations to reconstruct the weather of 1903, the researchers created a simulated version of the same year under higher temperatures and carbon dioxide levels. By holding weather patterns constant, the scientists were able to isolate the impacts of climate change that are directly related to changes in temperature and humidity, rather than shifts in weather patterns.

The study shows that warming does not affect all days equally. While temperatures rise across the board, the most noticeable increases occur during both cold snaps and warm spells. Days that would once sit below freezing are pushed upward, while those above 20°C see the most pronounced jumps.

This could have wide implications, from reducing frost days that ecosystems rely on, to intensifying heat exposure for vulnerable people during already warm periods.

“By anchoring our analysis in real historical weather patterns, we are able to provide a more tangible sense of how a warming world translates into lived experience,” explains Dr Rhidian Thomas, climate scientist at the National Centre for Atmospheric Science and University of Reading.

Beyond temperature, the study highlights a shift in the characteristics of rainfall. While rainfall may decrease in some regions, the way it falls changes. Lighter rain becomes less common, heavy downpours become more frequent, and dry spells are punctuated by heavier bursts of rain – which could increase the risk of flooding and complicate water management.

For countries in the Western Mediterranean, the study shows that rainfall can decline outside of the winter months, even without changes in the position of storm tracks.

The research team includes scientists from the National Centre for Atmospheric Science, University of Reading, University of Edinburgh, University of Colorado at Boulder, and NOAA Physical Sciences Laboratory.

The work is funded by the Natural Environment Research Council, and uses JASMIN – the UK’s collaborative data analysis environment.