Every heat event the pipeline tracked between 2018-05-01 and 2018-09-30, 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
102.16 Mkm²·days
Longest
35days (#14)
Hottest
+18.7°C (#3)
With a heat dome
11of 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 #14 — 2018-07-07 → 2018-08-10 35 daysheat dome · 22/35 d · Z500 +264 m
peak 1.90 M km² on 2018-08-02 · max +15.7 °C · mean +7.9 °C · burden 23.70 M km²·d · drift 703 km (65.8 N 22.5 E → 59.9 N 17.5 E)
Event #3 — 2018-05-05 → 2018-06-05 32 daysheat dome · 25/32 d · Z500 +316 m
peak 1.89 M km² on 2018-05-14 · max +18.7 °C · mean +9.9 °C · burden 18.73 M km²·d · drift 216 km (55.6 N 9.8 E → 57.5 N 10.3 E)
Event #2 — 2018-05-01 → 2018-05-09 9 dayshigh on 1/8 d only
peak 2.09 M km² on 2018-05-03 · max +13.6 °C · mean +8.9 °C · burden 11.39 M km²·d · drift 391 km (49.4 N 33.4 E → 51.0 N 38.3 E)
Event #24 — 2018-09-16 → 2018-09-24 9 daysheat dome · 7/9 d · Z500 +173 m
peak 2.46 M km² on 2018-09-20 · max +13.6 °C · mean +8.9 °C · burden 11.06 M km²·d · drift 3302 km (44.5 N 9.6 E → 68.2 N 44.3 E)
Event #20 — 2018-08-25 → 2018-09-11 18 dayshigh on 4/18 d only
peak 794k km² on 2018-09-01 · max +12.1 °C · mean +7.8 °C · burden 9.60 M km²·d · drift 546 km (54.6 N 33.7 E → 56.8 N 25.9 E)
Event #6 — 2018-05-20 → 2018-06-04 16 dayshigh on 3/16 d only
peak 977k km² on 2018-05-30 · max +13.3 °C · mean +8.1 °C · burden 5.07 M km²·d · drift 461 km (53.3 N 6.3 E → 56.5 N 10.9 E)
Event #12 — 2018-06-24 → 2018-07-07 14 dayshigh on 2/14 d only
peak 698k km² on 2018-06-29 · max +13.2 °C · mean +6.8 °C · burden 4.80 M km²·d · drift 1297 km (50.2 N 45.0 E → 38.6 N 44.7 E)
Event #25 — 2018-09-22 → 2018-09-30 9 dayshigh on 3/9 d only
peak 623k km² on 2018-09-23 · max +12.0 °C · mean +7.2 °C · burden 2.33 M km²·d · drift 178 km (39.8 N -4.3 E → 41.3 N -4.7 E)
Event #17 — 2018-07-21 → 2018-07-31 11 dayshigh on 1/11 d only
peak 493k km² on 2018-07-26 · max +12.5 °C · mean +8.1 °C · burden 1.99 M km²·d · drift 197 km (55.4 N 10.0 E → 53.8 N 8.8 E)
Event #10 — 2018-06-23 → 2018-07-10 18 daysheat dome · 14/18 d · Z500 +307 m
peak 158k km² on 2018-06-28 · max +12.0 °C · mean +6.8 °C · burden 1.89 M km²·d · drift 64 km (50.8 N -3.6 E → 51.3 N -4.0 E)
Event #15 — 2018-07-08 → 2018-07-14 7 dayshigh on 1/7 d only
peak 463k km² on 2018-07-11 · max +11.5 °C · mean +6.1 °C · burden 1.68 M km²·d · drift 392 km (41.4 N 40.7 E → 44.6 N 38.8 E)
Event #18 — 2018-08-06 → 2018-08-10 5 daysheat dome · 3/5 d · Z500 +186 m
peak 456k km² on 2018-08-08 · max +13.3 °C · mean +8.2 °C · burden 1.40 M km²·d · drift 851 km (52.1 N 10.4 E → 54.8 N 22.4 E)
Event #21 — 2018-09-09 → 2018-09-14 6 daysheat dome · 4/6 d · Z500 +195 m
peak 376k km² on 2018-09-12 · max +11.2 °C · mean +6.7 °C · burden 1.24 M km²·d · drift 585 km (46.1 N 14.1 E → 48.4 N 21.1 E)
Event #19 — 2018-08-08 → 2018-08-12 5 daysheat dome · 4/5 d · Z500 +186 m
peak 405k km² on 2018-08-10 · max +10.5 °C · mean +7.3 °C · burden 1.22 M km²·d · drift 771 km (65.8 N 31.8 E → 60.2 N 40.8 E)
Event #7 — 2018-06-06 → 2018-06-10 5 dayshigh on 1/5 d only
peak 331k km² on 2018-06-08 · max +10.1 °C · mean +7.6 °C · burden 1.03 M km²·d · drift 708 km (55.0 N 8.7 E → 52.1 N 18.3 E)
Event #23 — 2018-09-11 → 2018-09-16 6 daysheat dome · 4/6 d · Z500 +184 m
peak 201k km² on 2018-09-13 · max +10.9 °C · mean +8.3 °C · burden 660k km²·d · drift 254 km (52.6 N 39.7 E → 52.8 N 43.5 E)
Event #8 — 2018-06-06 → 2018-06-11 6 dayshigh on 1/6 d only
peak 192k km² on 2018-06-08 · max +10.3 °C · mean +7.7 °C · burden 652k km²·d · drift 672 km (60.8 N 8.0 E → 56.3 N 15.8 E)
Event #13 — 2018-06-24 → 2018-06-30 7 dayshigh on 3/7 d only
peak 171k km² on 2018-06-26 · max +11.7 °C · mean +7.7 °C · burden 596k km²·d · drift 175 km (59.2 N 10.9 E → 59.1 N 7.9 E)
Event #22 — 2018-09-09 → 2018-09-13 5 daysheat dome · 3/5 d · Z500 +195 m
peak 165k km² on 2018-09-11 · max +11.4 °C · mean +7.9 °C · burden 587k km²·d · drift 85 km (46.7 N 5.4 E → 46.0 N 5.9 E)
Event #5 — 2018-05-15 → 2018-05-21 7 dayshigh on 2/7 d only
peak 168k km² on 2018-05-17 · max +9.9 °C · mean +7.7 °C · burden 547k km²·d · drift 529 km (49.2 N 43.0 E → 44.6 N 44.7 E)
Event #9 — 2018-06-20 → 2018-06-23 4 daysheat dome · 3/4 d · Z500 +134 m
peak 146k km² on 2018-06-21 · max +9.1 °C · mean +6.7 °C · burden 469k km²·d · drift 166 km (45.3 N 40.2 E → 45.6 N 42.3 E)
Event #11 — 2018-06-24 → 2018-07-04 11 daysno overlying high
peak 110k km² on 2018-06-30 · max +10.0 °C · mean +6.8 °C · burden 418k km²·d · drift 735 km (48.1 N -4.3 E → 51.1 N 4.9 E)
Event #1 — 2018-05-01 → 2018-05-05 5 daysno overlying high
peak 106k km² on 2018-05-03 · max +10.2 °C · mean +7.1 °C · burden 404k km²·d · drift 153 km (39.4 N 30.1 E → 38.3 N 29.0 E)
Event #4 — 2018-05-05 → 2018-05-08 4 daysheat dome · 3/4 d · Z500 +246 m
peak 119k km² on 2018-05-07 · max +10.7 °C · mean +8.2 °C · burden 369k km²·d · drift 73 km (52.7 N -1.5 E → 52.6 N -0.4 E)
Event #16 — 2018-07-14 → 2018-07-19 6 daysno overlying high
peak 102k km² on 2018-07-16 · max +9.2 °C · mean +6.6 °C · burden 349k km²·d · drift 109 km (59.1 N 25.3 E → 58.6 N 26.9 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.