Measuring Heatwaves and Their Impacts, Table 1 Index register, inputs, considerations and outputs of existing
heatwave indices
Index
Description
Max.
temperature
Min.
temperature
Relative
humidity Other
Intensity
output
Reference
Excess heat
factor (EHF)
Based on excess
heat indices
(EHIs) –
minimum/max
temperature
average over
3 days
X
X
X
Nairn and
Fawcett [20]
Excess heat
index
acclimatization
(EHI(accl.))
Minimum/max
temp. Average
over 3 days, less
the mean
max/min temp
over the
preceding
30 days
X
X
Nairn et al.
[21]
Excess heat
index absolute
(EHI(sig.))
Min/max temp.
Average over
3 days, less the
95th percentile
of this average
historically
X
X
Nairn et al.
[21]
Three-day
maximum
temperature
(3DMT)
The lowest
maximum
temperature
over a three-day
period. NSW
and QLD in
Australia use
the 90th
percentile for
the specific date
as a threshold
X
Scalley et al.
[22]
Daily average
temperature
(DAT)
Average of
maximum and
minimum
temperature
over 1 day.
Victoria uses
this index with a
threshold
between 30
C
and 34
C
X
Scalley et al.
[22]
Three-day
average with
activation
temp. (3DAT)
The DAT
averaged over a
three-day
period.
A threshold of
32
C is applied
in South
Australia and
Western
Australia
X
X
Scalley et al.
[22]
(continued)
458
Measuring Heatwaves and Their Impacts