DARLING RIVERINE PLAINS BIOREGION Background Report

16/08/02 Darling Riverine Plains Bioregion Background Report
km/hr
14
13
12
11
10
9
8
7
mean monthly 3pm wind speed
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
month
Bourke Walgett
Figure 2.11 Mean monthly wind speed at 3pm
2.2.3 Temperature and evaporation
In general terms the summers are mild to hot and winters mild to cool. Across the bioregion
the average annual temperatures increase from 17ºC in the south east to 20ºC in the
northwest. Most of the bioregion has an annual average temperature of 18 or 19ºC (Map 15).
The average mean maximum temperature in January ranges from 33ºC to 36ºC and the
average mean minimum temperature in July ranges from 3ºC to 6ºC (Bureau of Meteorology
2001). The mean monthly maximum and mean monthly minimum temperatures are illustrated
in Figure 2.12 and Figure 2.13.
Average annual potential evaporation varies from 1 800 mm east of Trangie to 2 000 mm
west of Bourke (Wolfgang 1998). Total average annual evaporation figures range from 2 131
mm at Moree to 1 825 mm at Bourke. Mean daily evaporation has been recorded for the
Bourke and Walgett weather stations within the DRP. These figures are graphed in Figure
2.14 and range from 1.7mm at Walgett in June to 8.5 mm at Bourke in December (Bureau of
Meteorology 2001).
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