Every heat event the pipeline tracked between 1998-05-01 and 1998-09-30, with how each one grew, peaked and moved. Anomalies are against the 1991–2020 baseline.
Season at a glance
Events tracked
20
Total heat burden
51.84 Mkm²·days
Longest
22days (#6)
Hottest
+16.0°C (#6)
With a heat dome
7of 20 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 #6 — 1998-06-03 → 1998-06-24 22 daysheat dome · 14/22 d · Z500 +315 m
peak 1.55 M km² on 1998-06-11 · max +16.0 °C · mean +8.6 °C · burden 16.42 M km²·d · drift 2468 km (45.1 N 16.4 E → 38.0 N 44.7 E)
Event #2 — 1998-05-07 → 1998-05-21 15 dayshigh on 6/15 d only
peak 1.60 M km² on 1998-05-11 · max +13.3 °C · mean +8.2 °C · burden 8.37 M km²·d · drift 441 km (43.9 N -1.0 E → 47.7 N -3.0 E)
Event #13 — 1998-07-29 → 1998-08-11 14 dayshigh on 2/14 d only
peak 1.56 M km² on 1998-08-03 · max +10.3 °C · mean +6.1 °C · burden 7.74 M km²·d · drift 1373 km (48.1 N 41.1 E → 35.9 N 38.9 E)
Event #14 — 1998-08-04 → 1998-08-17 14 dayshigh on 7/14 d only
peak 996k km² on 1998-08-10 · max +13.0 °C · mean +7.5 °C · burden 4.52 M km²·d · drift 1561 km (40.7 N -8.6 E → 45.5 N 9.5 E)
Event #16 — 1998-08-22 → 1998-09-02 12 dayshigh on 1/12 d only
peak 545k km² on 1998-08-28 · max +10.2 °C · mean +5.0 °C · burden 3.11 M km²·d · drift 978 km (37.1 N 33.5 E → 38.8 N 44.4 E)
Event #10 — 1998-07-14 → 1998-07-26 13 dayshigh on 3/13 d only
peak 276k km² on 1998-07-20 · max +9.8 °C · mean +4.9 °C · burden 2.07 M km²·d · drift 378 km (37.1 N 41.3 E → 38.8 N 37.6 E)
Event #1 — 1998-05-03 → 1998-05-11 9 daysheat dome · 8/9 d · Z500 +193 m
peak 409k km² on 1998-05-06 · max +12.7 °C · mean +7.6 °C · burden 1.93 M km²·d · drift 1032 km (41.2 N 32.3 E → 38.2 N 43.7 E)
Event #11 — 1998-07-20 → 1998-07-25 6 dayshigh on 3/6 d only
peak 279k km² on 1998-07-22 · max +9.7 °C · mean +6.5 °C · burden 948k km²·d · drift 393 km (48.7 N 20.0 E → 47.3 N 24.8 E)
Event #8 — 1998-06-27 → 1998-07-07 11 dayshigh on 2/11 d only
peak 134k km² on 1998-06-30 · max +13.6 °C · mean +6.6 °C · burden 783k km²·d · drift 461 km (36.3 N 8.6 E → 35.0 N 3.8 E)
Event #18 — 1998-09-13 → 1998-09-22 10 daysno overlying high
peak 158k km² on 1998-09-16 · max +11.9 °C · mean +6.7 °C · burden 713k km²·d · drift 590 km (44.4 N 38.9 E → 40.7 N 44.1 E)
Event #17 — 1998-09-12 → 1998-09-15 4 daysheat dome · 3/4 d · Z500 +209 m
peak 207k km² on 1998-09-13 · max +9.8 °C · mean +7.6 °C · burden 623k km²·d · drift 316 km (55.9 N 39.4 E → 58.7 N 39.6 E)
Event #5 — 1998-06-01 → 1998-06-07 7 daysheat dome · 4/7 d · Z500 +146 m
peak 145k km² on 1998-06-04 · max +9.1 °C · mean +5.9 °C · burden 606k km²·d · drift 412 km (37.7 N 14.3 E → 41.4 N 15.1 E)
Event #3 — 1998-05-12 → 1998-05-21 10 daysheat dome · 6/10 d · Z500 +274 m
peak 111k km² on 1998-05-16 · max +9.1 °C · mean +6.2 °C · burden 583k km²·d · drift 215 km (51.0 N -0.8 E → 50.5 N -3.8 E)
Event #7 — 1998-06-26 → 1998-07-04 9 dayshigh on 2/9 d only
peak 110k km² on 1998-07-01 · max +11.4 °C · mean +5.8 °C · burden 562k km²·d · drift 791 km (44.2 N 11.8 E → 37.4 N 14.6 E)
Event #15 — 1998-08-21 → 1998-08-25 5 dayshigh on 2/5 d only
peak 135k km² on 1998-08-23 · max +9.5 °C · mean +5.8 °C · burden 525k km²·d · drift 124 km (40.6 N -8.2 E → 39.9 N -7.0 E)
Event #12 — 1998-07-22 → 1998-07-30 9 dayshigh on 3/9 d only
peak 126k km² on 1998-07-25 · max +7.8 °C · mean +6.0 °C · burden 504k km²·d · drift 178 km (44.5 N 38.3 E → 45.0 N 40.4 E)
Event #4 — 1998-05-14 → 1998-05-18 5 daysheat dome · 5/5 d · Z500 +310 m
peak 128k km² on 1998-05-16 · max +12.7 °C · mean +8.9 °C · burden 501k km²·d · drift 143 km (61.0 N 9.9 E → 61.3 N 12.5 E)
Event #20 — 1998-09-19 → 1998-09-24 6 daysheat dome · 5/6 d · Z500 +326 m
peak 126k km² on 1998-09-22 · max +9.2 °C · mean +5.9 °C · burden 484k km²·d · drift 41 km (59.7 N 8.5 E → 60.0 N 8.2 E)
Event #19 — 1998-09-15 → 1998-09-22 8 dayshigh on 1/8 d only
peak 128k km² on 1998-09-20 · max +10.9 °C · mean +8.1 °C · burden 463k km²·d · drift 334 km (49.5 N 44.9 E → 49.8 N 40.3 E)
Event #9 — 1998-06-30 → 1998-07-04 5 dayshigh on 2/5 d only
peak 100k km² on 1998-07-02 · max +11.8 °C · mean +6.3 °C · burden 375k km²·d · drift 142 km (39.5 N 21.7 E → 38.5 N 22.7 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.