Heat waves Tracker
Extended extreme heat with excess mortality and infrastructure stress. We record every heat wave our sources report worldwide, plot it on the map and give it its own detailed page.
About heat waves
Heat kills quietly, mostly through cardiovascular and kidney stress in older adults, outdoor workers and people without cooling. Overnight temperature matters as much as the daytime peak, because bodies need cool hours to recover.
Safety guidance
- Drink water before feeling thirsty and avoid alcohol and heavy meals in peak heat.
- Check on older neighbours, people living alone and outdoor workers daily.
- Never leave children or animals in a parked vehicle.
- Know heat-stroke signs: confusion, hot dry skin, collapse — these are medical emergencies.
Right now: El Niño
NOAA has an El Niño Advisory in force (issued 8 October 2026). Sea temperatures in the central tropical Pacific ran 2.2 °C above normal in Jul–Sep 2026, on the Oceanic Niño Index.
El Niño releases ocean heat into the atmosphere; the record-warm years 2016 and 2024 each came just after one peaked.
A tendency across past events, not a forecast for any one place. Source: NOAA Climate Prediction Center.
Get alerts for heat waves
Choose the countries you care about and get new heat waves by email digest or phone push — only when one is recorded.
Twelve-month trend
Latest recorded heat waves
Most affected countries
| # | Country | Records |
|---|---|---|
| 1 | Austria | 904 |
| 2 | United States | 335 |
| 3 | Belgium | 186 |
| 4 | Spain | 148 |
| 5 | Bosnia and Herzegovina | 56 |
| 6 | Switzerland | 49 |
| 7 | Czech Republic | 29 |
| 8 | Italy | 28 |
| 9 | Bulgaria | 28 |
| 10 | Brazil | 23 |
| 11 | France | 14 |
| 12 | Greece | 10 |