Every heat event the pipeline tracked between 2003-05-01 and 2003-09-30, with how each one grew, peaked and moved. Anomalies are against the 1991–2020 baseline.
Season at a glance
Events tracked
24
Total heat burden
92.10 Mkm²·days
Longest
28days (#16)
Hottest
+15.9°C (#16)
With a heat dome
14of 24 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 #16 — 2003-07-29 → 2003-08-25 28 dayshigh on 8/28 d only
peak 1.58 M km² on 2003-08-12 · max +15.9 °C · mean +8.2 °C · burden 17.03 M km²·d · drift 1682 km (38.5 N -7.7 E → 42.2 N 11.6 E)
Event #1 — 2003-05-01 → 2003-05-16 16 daysheat dome · 10/15 d · Z500 +194 m
peak 1.40 M km² on 2003-05-08 · max +13.8 °C · mean +8.4 °C · burden 14.90 M km²·d · drift 1027 km (43.4 N 22.1 E → 47.2 N 34.1 E)
Event #8 — 2003-06-04 → 2003-06-30 27 daysheat dome · 19/27 d · Z500 +177 m
peak 1.70 M km² on 2003-06-12 · max +15.2 °C · mean +7.0 °C · burden 13.22 M km²·d · drift 741 km (47.9 N 17.2 E → 43.0 N 10.8 E)
Event #23 — 2003-09-10 → 2003-09-24 15 daysheat dome · 12/15 d · Z500 +255 m
peak 1.99 M km² on 2003-09-21 · max +13.8 °C · mean +8.1 °C · burden 10.60 M km²·d · drift 2848 km (37.6 N -8.4 E → 46.4 N 24.3 E)
Event #15 — 2003-07-23 → 2003-08-06 15 daysheat dome · 8/15 d · Z500 +241 m
peak 1.19 M km² on 2003-07-31 · max +15.4 °C · mean +7.7 °C · burden 7.77 M km²·d · drift 716 km (67.5 N 40.5 E → 61.2 N 44.0 E)
Event #14 — 2003-07-13 → 2003-07-23 11 daysheat dome · 8/11 d · Z500 +241 m
peak 801k km² on 2003-07-15 · max +13.3 °C · mean +7.8 °C · burden 4.38 M km²·d · drift 536 km (61.8 N 18.7 E → 65.6 N 25.7 E)
Event #4 — 2003-05-22 → 2003-05-29 8 daysheat dome · 7/8 d · Z500 +197 m
peak 1.10 M km² on 2003-05-25 · max +12.2 °C · mean +7.9 °C · burden 4.20 M km²·d · drift 552 km (46.9 N 39.6 E → 47.0 N 32.3 E)
Event #2 — 2003-05-01 → 2003-05-15 15 daysheat dome · 8/14 d · Z500 +194 m
peak 513k km² on 2003-05-04 · max +11.6 °C · mean +7.1 °C · burden 3.27 M km²·d · drift 666 km (39.1 N 27.6 E → 38.7 N 35.3 E)
Event #11 — 2003-07-01 → 2003-07-07 7 dayshigh on 2/7 d only
peak 866k km² on 2003-07-04 · max +10.4 °C · mean +5.6 °C · burden 3.10 M km²·d · drift 1537 km (43.9 N 24.9 E → 37.3 N 40.9 E)
Event #22 — 2003-09-05 → 2003-09-12 8 daysheat dome · 8/8 d · Z500 +181 m
peak 511k km² on 2003-09-09 · max +8.5 °C · mean +5.8 °C · burden 2.27 M km²·d · drift 553 km (64.5 N 21.3 E → 66.8 N 31.9 E)
Event #12 — 2003-07-07 → 2003-07-16 10 dayshigh on 4/10 d only
peak 430k km² on 2003-07-13 · max +11.2 °C · mean +7.5 °C · burden 1.70 M km²·d · drift 576 km (43.5 N 3.3 E → 48.3 N 6.1 E)
Event #10 — 2003-06-29 → 2003-07-04 6 daysheat dome · 5/6 d · Z500 +261 m
peak 417k km² on 2003-07-02 · max +14.7 °C · mean +8.0 °C · burden 1.55 M km²·d · drift 461 km (68.5 N 17.7 E → 66.4 N 27.0 E)
Event #5 — 2003-05-28 → 2003-06-02 6 daysheat dome · 5/6 d · Z500 +144 m
peak 367k km² on 2003-05-30 · max +9.8 °C · mean +6.9 °C · burden 1.26 M km²·d · drift 651 km (44.3 N 2.2 E → 49.9 N 5.1 E)
Event #17 — 2003-08-04 → 2003-08-14 11 daysheat dome · 8/11 d · Z500 +243 m
peak 186k km² on 2003-08-09 · max +12.6 °C · mean +7.1 °C · burden 1.17 M km²·d · drift 244 km (52.9 N -1.7 E → 50.8 N -1.6 E)
Event #24 — 2003-09-12 → 2003-09-18 7 daysheat dome · 5/7 d · Z500 +255 m
peak 173k km² on 2003-09-15 · max +9.4 °C · mean +5.7 °C · burden 823k km²·d · drift 379 km (57.4 N -2.5 E → 54.2 N -0.7 E)
Event #7 — 2003-06-01 → 2003-06-06 6 daysheat dome · 5/6 d · Z500 +151 m
peak 223k km² on 2003-06-04 · max +12.1 °C · mean +8.5 °C · burden 790k km²·d · drift 459 km (52.7 N 10.8 E → 50.0 N 15.8 E)
Event #20 — 2003-08-28 → 2003-09-01 5 dayshigh on 2/5 d only
peak 230k km² on 2003-08-30 · max +12.1 °C · mean +7.6 °C · burden 711k km²·d · drift 517 km (44.6 N 22.9 E → 41.6 N 27.7 E)
Event #13 — 2003-07-13 → 2003-07-19 7 dayshigh on 1/7 d only
peak 164k km² on 2003-07-14 · max +11.5 °C · mean +7.3 °C · burden 625k km²·d · drift 504 km (53.9 N -3.0 E → 58.3 N -4.9 E)
Event #21 — 2003-08-29 → 2003-09-03 6 dayshigh on 2/6 d only
peak 185k km² on 2003-09-01 · max +8.6 °C · mean +5.4 °C · burden 571k km²·d · drift 703 km (38.8 N 27.3 E → 37.7 N 35.2 E)
Event #19 — 2003-08-21 → 2003-09-03 14 dayshigh on 2/14 d only
peak 126k km² on 2003-08-29 · max +11.5 °C · mean +6.0 °C · burden 565k km²·d · drift 538 km (36.9 N 10.9 E → 35.1 N 5.3 E)
Event #9 — 2003-06-22 → 2003-07-03 12 dayshigh on 4/12 d only
peak 113k km² on 2003-06-30 · max +15.0 °C · mean +6.3 °C · burden 482k km²·d · drift 229 km (37.0 N 9.1 E → 35.4 N 7.6 E)
Event #3 — 2003-05-12 → 2003-05-17 6 dayshigh on 2/6 d only
peak 129k km² on 2003-05-15 · max +12.2 °C · mean +8.9 °C · burden 403k km²·d · drift 439 km (69.7 N 29.3 E → 66.6 N 35.9 E)
Event #6 — 2003-05-28 → 2003-06-02 6 daysheat dome · 5/6 d · Z500 +144 m
peak 111k km² on 2003-05-31 · max +9.5 °C · mean +6.3 °C · burden 376k km²·d · drift 174 km (53.4 N -2.8 E → 53.9 N -0.2 E)
Event #18 — 2003-08-08 → 2003-08-12 5 daysno overlying high
peak 124k km² on 2003-08-11 · max +8.5 °C · mean +5.2 °C · burden 342k km²·d · drift 396 km (35.7 N 43.1 E → 39.1 N 44.5 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.