94
R. Kimura
4.2 Temperature
The annual average, average maximum, and average minimum temperatures from
2007 to 2016 at Dakhla were 24.4, 32.9, and 15.9 °C, respectively (Fig. 2). The daily
maximum and minimum temperatures were 42.5 and 4.4 °C, respectively. The diurnal
temperature amplitude averaged 16.9 °C, with an average maximum of 21.2 °C and
an average minimum of 12.4 °C. Seasonal variation in daily temperature is small
from June to August and large during other periods, especially March to May when
the Khamsin wind prevails. The temperature was never below 0 °C.
Dakhla’s temperatures are typical of a desert climate, including the large diurnal
amplitude, but it is not too severe for human activity. The comfortable season for
human activity is comparatively long, from October to April, based on a discomfort
index calculated from monthly maximum daily averaged temperature and humidity
(Fig. 3). For agriculture, the ET p demands during the summer are large (Fig. 1); therefore, cultivation during winter makes sense from a water-conservation perspective.
It is interesting to note that the period most comfortable for humans nearly coincides
with the winter agricultural production period. However, because and temperature is
sufficient for agriculture, cultivation with relatively little or no rainfall depends on
the availability of groundwater in Dakhla Oasis, even during the summer. Wet rice
farming is conducted once every few years.
0
5
10
15
20
25
30
35
40
45
1
31
61
91 121 151 181 211 241 271 301 331 361
Temperature (Υ)
Day of year
Daily average
Daily maximum
Daily minimum
Fig. 2 Seasonal change of daily average, maximum, and minimum temperatures averaged from
2007 to 2016 in Dakhla Oasis. Some parts are modified after Kimura et al. (2020)
R. Kimura
4.2 Temperature
The annual average, average maximum, and average minimum temperatures from
2007 to 2016 at Dakhla were 24.4, 32.9, and 15.9 °C, respectively (Fig. 2). The daily
maximum and minimum temperatures were 42.5 and 4.4 °C, respectively. The diurnal
temperature amplitude averaged 16.9 °C, with an average maximum of 21.2 °C and
an average minimum of 12.4 °C. Seasonal variation in daily temperature is small
from June to August and large during other periods, especially March to May when
the Khamsin wind prevails. The temperature was never below 0 °C.
Dakhla’s temperatures are typical of a desert climate, including the large diurnal
amplitude, but it is not too severe for human activity. The comfortable season for
human activity is comparatively long, from October to April, based on a discomfort
index calculated from monthly maximum daily averaged temperature and humidity
(Fig. 3). For agriculture, the ET p demands during the summer are large (Fig. 1); therefore, cultivation during winter makes sense from a water-conservation perspective.
It is interesting to note that the period most comfortable for humans nearly coincides
with the winter agricultural production period. However, because and temperature is
sufficient for agriculture, cultivation with relatively little or no rainfall depends on
the availability of groundwater in Dakhla Oasis, even during the summer. Wet rice
farming is conducted once every few years.
0
5
10
15
20
25
30
35
40
45
1
31
61
91 121 151 181 211 241 271 301 331 361
Temperature (Υ)
Day of year
Daily average
Daily maximum
Daily minimum
Fig. 2 Seasonal change of daily average, maximum, and minimum temperatures averaged from
2007 to 2016 in Dakhla Oasis. Some parts are modified after Kimura et al. (2020)