Global annual radar spiral · loading latest 2026 ERA5T…
Global monthly heatwave character through time
19402026 latest
Historical evidence · 1940–2025
Historical Heatwave Analytics
Move from “how many events?” to research-ready comparisons of global character, interannual change, generational exposure, annual Top-10 context, and event-level distributions.
Loading 1940–2025 event evidence…
- Historical archive
- 15,634 events · 1940–2025
- Spatial unit
- 46 AR6 land regions
- Event source
- ERA5 daily maximum 2 m temperature
- Current comparison
- 2026 ERA5T · through latest observation
01
Global character
How has the global mean heatwave character changed through time?
The line starts empty in January 1940 and never resets at a new year. It grows as one continuous monthly path through the latest 2026 ERA5T observation. The latest 12 months form a moving tail whose opacity, width, and glow recede smoothly month by month. Lock the 3D stack, then use the year slider to inspect any historical cutoff without returning to 2D.
02
Interannual change
How do heatwave event characteristics change from year to year within a selected spatial scope?
Choose Globe or one of the 46 AR6 AREA regions, then select a heatwave characteristic. Globe Frequency is the annual total event count divided by 46 AREA regions. For other Globe characteristics, each variable defines its own annual Top 10: HWMS ranks by HWMS, HWMM by HWMM, HWD by HWD, and so on. A selected AREA keeps all events assigned to that region. The horizontal axis follows 1940–2025; HWV is excluded.
Annual spatial series · 1940–2025
One AREA annual series
03
Generational lens
What heatwave history did different generations encounter at the same age?
Compare generations at equal ages using the mean annual statistic for the selected spatial scope across each generation's birth-year band.
Generation × age heatwave exposure
Generation × age exposure matrix
04
Annual Top-10 events in historical context
How do the average characteristics of each year's ten highest-HWMS events compare?
Each bubble represents one year. Position shows Top-10 mean HWD and HWMA, size follows log10 of Top-10 mean HWMS, and color shows Top-10 mean HWMM. Select a year or click a bubble to inspect its ten events. The 2026 bubble is provisional because the year is still incomplete.
Annual Top-10 event means
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Loading annual Top-10 summaries…
Selected-year outline
Color: Top-10 mean HWMM
X: mean HWD · log axis
Y: mean HWMA · log axis
Size: log10(mean HWMS)
Top 10 membership is ranked by raw HWMS. Bubble size follows log10(mean HWMS), fill color follows mean HWMM, and the 2026 value is preliminary because it covers only the latest available part of the year.
05
Global event distribution
Where does a known heatwave sit in the global archive?
Compare one event with the probability distribution of all unique global events from 1940 to 2025. The density uses the complete archive rather than annual Top-10 means. Documented benchmark events and the three strongest 2022–2025 events for the selected characteristic provide interpretable reference points.
Probability density and percentile context
Global event distribution
Preparing the global event distribution…
Historical records are deduplicated by Year and Number before estimating the global distribution. The histogram and smoothed density use the same transformed values; HWMS is shown as log10(HWMS). A 2026 ERA5T event, when selected, is a provisional marker only and is never included in the 1940–2025 reference distribution.