Table 1

Number, average temperature and effect of heatwave days

Heatwave definition 1Heatwave definition 2Heatwave definition 3Heatwave definition 4
Definition≥ 90th percentile* for ≥2 days†≥ 95th percentile* for ≥2 days†≥ 98th percentile* for ≥2 days†≥ 99th percentile* for ≥2 days†
Total heatwave days‡305130357
Average (range) temperature of heatwave days (oC)27.0 (25.1–30.1)27.6 (26.0–30.0)28.2 (26.7–29.8)28.6 (28.1–28.9)
Main effect (RR, 95% CI)1.19 (1.00 to 1.41)1.25 (1.04 to 1.50)1.38 (1.09 to 1.75)1.48 (1.11 to 1.96)
Added effect (RR, 95% CI)0.99 (0.94 to 1.04)1.03 (0.96 to 1.11)0.92 (0.81 to 1.04)0.79 (0.60 to 1.04)
  • *Percentile of the yearly temperature distribution.

  • †Consecutive days.

  • ‡During the entire study period (1 January 2007 and 31 December 2019).

  • RR, relative risk.