Every heat event the pipeline tracked between 2025-05-01 and 2025-09-30, with how each one grew, peaked and moved. Anomalies are against the 1991–2020 baseline.
Season at a glance
Events tracked
25
Total heat burden
136.23 Mkm²·days
Longest
70days (#8)
Hottest
+16.8°C (#4)
With a heat dome
14of 25 events
A heat dome is the stricter object: a tracked heat event with a closed 500 hPa anticyclone whose influence cap overlies it, after Loikith et al. (2026). Most heatwaves are not domes, so the label is a finding and not a synonym.
ERA5 daily maximum 2 m temperature over land, against the 1991–2020 climatology (p90 in a centred 15-day window). A heatwave cell is Tx above p90 on at least 3 consecutive days.
When the events ran
Overlapping bars are concurrent events in different places, not one event counted twice: each is a separately labelled cluster of contiguous heatwave cells.
How each event evolved
Event #8 — 2025-05-30 → 2025-08-07 70 daysheat dome · 55/70 d · Z500 +315 m
peak 1.75 M km² on 2025-07-12 · max +16.4 °C · mean +7.7 °C · burden 61.25 M km²·d · drift 2969 km (44.3 N 9.8 E → 65.1 N 40.0 E)
Event #21 — 2025-08-17 → 2025-09-18 33 daysheat dome · 18/33 d · Z500 +316 m
peak 1.59 M km² on 2025-08-31 · max +12.4 °C · mean +7.0 °C · burden 20.25 M km²·d · drift 2396 km (40.3 N 41.5 E → 61.9 N 42.4 E)
Event #18 — 2025-08-02 → 2025-08-19 18 daysheat dome · 10/18 d · Z500 +188 m
peak 1.72 M km² on 2025-08-14 · max +15.2 °C · mean +7.5 °C · burden 14.75 M km²·d · drift 729 km (41.9 N -8.2 E → 39.0 N -0.5 E)
Event #17 — 2025-07-19 → 2025-08-09 22 dayshigh on 4/22 d only
peak 1.04 M km² on 2025-07-27 · max +13.6 °C · mean +6.6 °C · burden 8.74 M km²·d · drift 2344 km (44.5 N 17.3 E → 38.3 N 44.3 E)
Event #22 — 2025-09-12 → 2025-09-24 13 daysheat dome · 10/13 d · Z500 +228 m
peak 1.55 M km² on 2025-09-20 · max +13.8 °C · mean +8.1 °C · burden 8.52 M km²·d · drift 2193 km (38.2 N -3.1 E → 44.3 N 22.0 E)
Event #6 — 2025-05-23 → 2025-05-31 9 daysheat dome · 7/9 d · Z500 +228 m
peak 557k km² on 2025-05-29 · max +15.8 °C · mean +9.4 °C · burden 3.18 M km²·d · drift 602 km (58.4 N 36.4 E → 54.7 N 43.5 E)
Event #7 — 2025-05-26 → 2025-06-03 9 daysheat dome · 6/9 d · Z500 +177 m
peak 646k km² on 2025-05-30 · max +12.2 °C · mean +7.6 °C · burden 3.07 M km²·d · drift 1025 km (38.0 N -3.8 E → 43.3 N 6.2 E)
Event #5 — 2025-05-17 → 2025-05-29 13 dayshigh on 2/13 d only
peak 509k km² on 2025-05-24 · max +12.7 °C · mean +6.1 °C · burden 2.62 M km²·d · drift 103 km (38.0 N 43.5 E → 38.8 N 43.9 E)
Event #11 — 2025-06-05 → 2025-06-15 11 dayshigh on 2/11 d only
peak 351k km² on 2025-06-12 · max +10.2 °C · mean +5.4 °C · burden 1.52 M km²·d · drift 658 km (37.4 N 36.5 E → 37.4 N 44.0 E)
Event #25 — 2025-09-25 → 2025-09-30 6 daysheat dome · 6/6 d · Z500 +325 m
peak 294k km² on 2025-09-28 · max +7.6 °C · mean +5.3 °C · burden 1.19 M km²·d · drift 240 km (66.7 N 26.2 E → 67.5 N 31.3 E)
Event #10 — 2025-06-05 → 2025-06-24 20 dayshigh on 2/20 d only
peak 141k km² on 2025-06-08 · max +11.0 °C · mean +6.3 °C · burden 1.17 M km²·d · drift 889 km (36.5 N 9.8 E → 35.5 N -0.0 E)
Event #9 — 2025-06-04 → 2025-06-13 10 dayshigh on 4/10 d only
peak 146k km² on 2025-06-09 · max +10.8 °C · mean +6.1 °C · burden 1.11 M km²·d · drift 124 km (38.7 N 28.8 E → 38.3 N 30.1 E)
Event #4 — 2025-05-11 → 2025-05-23 13 daysheat dome · 9/13 d · Z500 +361 m
peak 103k km² on 2025-05-16 · max +16.8 °C · mean +9.3 °C · burden 1.06 M km²·d · drift 122 km (66.3 N -22.1 E → 65.7 N -19.8 E)
Event #2 — 2025-05-01 → 2025-05-03 3 daysheat dome · 2/2 d · Z500 +157 m
peak 347k km² on 2025-05-01 · max +12.5 °C · mean +8.5 °C · burden 1.04 M km²·d · drift 0 km (47.3 N 3.1 E → 47.3 N 3.1 E)
Event #1 — 2025-05-01 → 2025-05-05 5 dayshigh on 2/4 d only
peak 321k km² on 2025-05-02 · max +11.9 °C · mean +6.8 °C · burden 977k km²·d · drift 364 km (46.0 N 13.7 E → 42.7 N 14.0 E)
Event #12 — 2025-06-11 → 2025-06-22 12 daysheat dome · 7/12 d · Z500 +189 m
peak 194k km² on 2025-06-20 · max +11.6 °C · mean +7.2 °C · burden 930k km²·d · drift 59 km (53.1 N -0.6 E → 52.9 N 0.2 E)
Event #23 — 2025-09-22 → 2025-09-24 3 daysheat dome · 2/3 d · Z500 +200 m
peak 267k km² on 2025-09-23 · max +14.7 °C · mean +10.1 °C · burden 797k km²·d · drift 5 km (49.6 N 40.8 E → 49.5 N 40.8 E)
Event #3 — 2025-05-08 → 2025-05-21 14 dayshigh on 4/14 d only
peak 142k km² on 2025-05-12 · max +10.3 °C · mean +6.7 °C · burden 783k km²·d · drift 137 km (57.3 N -3.8 E → 56.4 N -5.4 E)
Event #14 — 2025-07-08 → 2025-07-13 6 daysheat dome · 4/6 d · Z500 +265 m
peak 216k km² on 2025-07-11 · max +11.9 °C · mean +7.7 °C · burden 737k km²·d · drift 302 km (57.1 N -3.0 E → 54.5 N -3.9 E)
Event #24 — 2025-09-25 → 2025-09-30 6 daysheat dome · 6/6 d · Z500 +325 m
peak 165k km² on 2025-09-27 · max +8.9 °C · mean +5.6 °C · burden 595k km²·d · drift 128 km (67.0 N 19.7 E → 68.1 N 19.9 E)
Event #19 — 2025-08-08 → 2025-08-14 7 dayshigh on 1/7 d only
peak 151k km² on 2025-08-09 · max +11.5 °C · mean +5.9 °C · burden 556k km²·d · drift 147 km (35.4 N 37.2 E → 36.4 N 36.2 E)
Event #20 — 2025-08-10 → 2025-08-14 5 daysheat dome · 3/5 d · Z500 +188 m
peak 167k km² on 2025-08-12 · max +11.5 °C · mean +7.3 °C · burden 456k km²·d · drift 511 km (52.4 N -1.7 E → 56.9 N -3.6 E)
Event #15 — 2025-07-10 → 2025-07-13 4 dayshigh on 1/4 d only
peak 112k km² on 2025-07-11 · max +10.6 °C · mean +7.5 °C · burden 358k km²·d · drift 55 km (48.1 N -1.4 E → 48.3 N -0.7 E)
Event #13 — 2025-06-26 → 2025-06-29 4 daysno overlying high
peak 156k km² on 2025-06-27 · max +5.7 °C · mean +4.3 °C · burden 348k km²·d · drift 266 km (37.4 N 41.2 E → 38.5 N 43.8 E)
Event #16 — 2025-07-15 → 2025-07-18 4 dayshigh on 1/4 d only
peak 102k km² on 2025-07-17 · max +9.1 °C · mean +6.1 °C · burden 226k km²·d · drift 151 km (38.5 N -2.9 E → 38.5 N -1.2 E)
Filled area is the event footprint in km² (left axis); the solid line is the peak anomaly inside it and the dashed line the mean (right axis). The small panel is the centroid path, circles sized by area and the ring marking day one. Drift is the straight-line start-to-end distance, so a dome that wandered and returned reports a small number.