Every heat event the pipeline tracked between 1997-05-01 and 1997-09-30, with how each one grew, peaked and moved. Anomalies are against the 1991–2020 baseline.
Season at a glance
Events tracked
18
Total heat burden
44.81 Mkm²·days
Longest
33days (#11)
Hottest
+15.3°C (#5)
With a heat dome
12of 18 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 #11 — 1997-08-04 → 1997-09-05 33 daysheat dome · 21/33 d · Z500 +234 m
peak 771k km² on 1997-08-08 · max +13.0 °C · mean +6.7 °C · burden 7.70 M km²·d · drift 1107 km (65.7 N 22.2 E → 56.3 N 15.5 E)
Event #14 — 1997-08-19 → 1997-09-04 17 daysheat dome · 11/17 d · Z500 +221 m
peak 950k km² on 1997-08-26 · max +11.9 °C · mean +7.2 °C · burden 6.51 M km²·d · drift 431 km (60.2 N 26.3 E → 57.2 N 21.6 E)
Event #3 — 1997-05-12 → 1997-05-20 9 daysheat dome · 5/9 d · Z500 +189 m
peak 1.18 M km² on 1997-05-16 · max +11.1 °C · mean +7.5 °C · burden 5.57 M km²·d · drift 276 km (47.8 N 19.4 E → 45.6 N 17.8 E)
Event #4 — 1997-06-05 → 1997-06-16 12 daysheat dome · 7/12 d · Z500 +302 m
peak 1.19 M km² on 1997-06-09 · max +15.1 °C · mean +9.6 °C · burden 5.16 M km²·d · drift 1491 km (61.7 N 16.7 E → 55.6 N 39.9 E)
Event #2 — 1997-05-05 → 1997-05-16 12 dayshigh on 3/12 d only
peak 926k km² on 1997-05-10 · max +12.3 °C · mean +7.2 °C · burden 5.02 M km²·d · drift 702 km (40.6 N 29.8 E → 38.0 N 37.3 E)
Event #6 — 1997-06-28 → 1997-07-03 6 daysheat dome · 5/6 d · Z500 +176 m
peak 672k km² on 1997-06-30 · max +12.1 °C · mean +7.6 °C · burden 2.12 M km²·d · drift 1048 km (51.4 N 20.9 E → 59.6 N 29.2 E)
Event #12 — 1997-08-05 → 1997-08-21 17 daysheat dome · 13/17 d · Z500 +219 m
peak 180k km² on 1997-08-12 · max +9.3 °C · mean +5.5 °C · burden 1.89 M km²·d · drift 500 km (55.1 N -4.9 E → 51.9 N 0.5 E)
Event #9 — 1997-07-12 → 1997-07-20 9 daysheat dome · 6/9 d · Z500 +231 m
peak 328k km² on 1997-07-16 · max +11.4 °C · mean +7.3 °C · burden 1.60 M km²·d · drift 395 km (66.4 N 14.9 E → 66.8 N 23.8 E)
Event #18 — 1997-09-23 → 1997-09-30 8 dayshigh on 2/8 d only
peak 280k km² on 1997-09-28 · max +9.7 °C · mean +6.3 °C · burden 1.50 M km²·d · drift 249 km (47.2 N -1.6 E → 46.8 N 1.6 E)
Event #5 — 1997-06-07 → 1997-06-19 13 daysheat dome · 9/13 d · Z500 +129 m
peak 162k km² on 1997-06-12 · max +15.3 °C · mean +7.7 °C · burden 1.27 M km²·d · drift 289 km (35.7 N 5.2 E → 35.1 N 8.3 E)
Event #13 — 1997-08-06 → 1997-08-21 16 daysheat dome · 13/16 d · Z500 +219 m
peak 237k km² on 1997-08-12 · max +9.7 °C · mean +6.9 °C · burden 1.21 M km²·d · drift 143 km (57.2 N 9.8 E → 56.0 N 9.5 E)
Event #16 — 1997-08-28 → 1997-09-06 10 dayshigh on 3/10 d only
peak 280k km² on 1997-08-31 · max +11.4 °C · mean +6.4 °C · burden 1.11 M km²·d · drift 103 km (68.6 N 15.3 E → 68.8 N 17.8 E)
Event #7 — 1997-06-30 → 1997-07-04 5 daysheat dome · 4/5 d · Z500 +176 m
peak 306k km² on 1997-07-02 · max +11.4 °C · mean +7.8 °C · burden 1.01 M km²·d · drift 467 km (60.9 N 23.7 E → 61.4 N 32.3 E)
Event #1 — 1997-05-04 → 1997-05-09 6 dayshigh on 2/6 d only
peak 239k km² on 1997-05-06 · max +10.9 °C · mean +7.0 °C · burden 921k km²·d · drift 894 km (42.7 N 25.6 E → 49.2 N 32.4 E)
Event #8 — 1997-07-03 → 1997-07-06 4 dayshigh on 1/4 d only
peak 246k km² on 1997-07-04 · max +10.6 °C · mean +6.4 °C · burden 767k km²·d · drift 246 km (41.4 N 21.6 E → 42.1 N 24.4 E)
Event #10 — 1997-07-19 → 1997-07-26 8 daysheat dome · 6/8 d · Z500 +231 m
peak 134k km² on 1997-07-23 · max +9.1 °C · mean +6.5 °C · burden 565k km²·d · drift 380 km (63.5 N 19.6 E → 64.5 N 12.1 E)
Event #15 — 1997-08-21 → 1997-08-25 5 daysheat dome · 3/5 d · Z500 +164 m
peak 149k km² on 1997-08-23 · max +10.2 °C · mean +7.4 °C · burden 481k km²·d · drift 231 km (47.5 N 2.6 E → 49.2 N 4.4 E)
Event #17 — 1997-09-17 → 1997-09-20 4 dayshigh on 1/4 d only
peak 123k km² on 1997-09-18 · max +9.9 °C · mean +6.9 °C · burden 416k km²·d · drift 127 km (48.0 N -0.4 E → 47.6 N -2.0 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.