Measuring Heatwaves and Their Impacts, Table 1 (continued)
Index
Description
Max.
temperature
Min.
temperature
Relative
humidity Other
Intensity
output
Reference
Relatively
warm nights
Nights with a
minimum
temperature in
the upper 95th
percentile
X
Collins et al.
[31]
EHD/EHN
The number of
days/nights over
a period where
the maximum/
minimum
temperature
exceeds the 95th
percentile level
for that measure
X
X
Trigo et al.
[32]
Multiple
threshold index
A lower
threshold T2
(here the 81st
percentile)
temperature
must span the
duration of the
heatwave event
and contain a
shorter period of
3 days in which
the daily
maximum
temperature
must exceed
threshold T1
(here 97.5th
percentile). The
average daily
maximum
temperature
must be above
T1 for the entire
period
X
Meehl and
Tebaldi [33]
EEHD/EEHN
(exceedance
extreme hot
days/nights)
The sum of
exceedance
degrees on days/
nights over a
period where
the number
maximum/
minimum
temperature
exceeds the 95th
percentile level
for that measure
X
X
X
Trigo et al.
[32]
462
Measuring Heatwaves and Their Impacts