Climate

All climate information has been obtained from the freely available data provided on the Australian Bureau of Meteorology website- http://www.bom.gov.au/.

Station Locations

Station: 067033 RICHMOND RAAF  Latitude (deg S): -33.6022 Longitude (deg E): 150.7794 Elevation: 19 metres
Station: 068192 CAMDEN AIRPORT AWS Latitude (deg S): -34.0391 Longitude (deg E): 150.6890 Elevation: 73.9 metres

Climate Summary

A number of key industry indices, as described by Smart and Dry (1980), have been used to assess the climate parameters within the region and these can be viewed for the stations within the region in Table 1 below. An explanation of the indices used follow:

1. MJT - Mean January Temperature, also refers to the mean temperature of the warmest month (MTWM) .
2. MAR - Mean Average Range is calculated by taking the mean temperature of the warmest month (January) and then subtracting the mean temperature of the coolest month (July) - ie. MTWM - MTCM.
3. HDD - Heat Degree Days is worked out for the growing season (October-April) and is calculated by taking the difference between 10 °C and the mean temperature of the month, which is then multiplied by the number of days in the month. The resulting figure for each of the seven months is then tallied to give the HDD in degrees Celcius.
4. RH - Relative Humidity over the growing season (October-April)
5. SSH - Sunshine Hours per day over the growing season (October-April)

Table 1: Climate summary of the Sydney wine region

Station	MJT 1 (°C)	MAR 2 (°C)	HDD 3 (°C)	Annual Rainfall (mm)	Oct-Apr Rainfall (mm)	RH 4 (%)	SSH 5 (hrs/day)
Richmond	23.5	13.1	2296	810	573	72.3	7.1
Camden	22.9	12.9	2158	828	571	72.3	n.a.

Based on the information in the table above, we can conclude that Sydney is a hot to very hot, moderately continental, moderately sunny, very humid wine region. We can also say that it is an "east coast - hot humid" (Young, 1995) growing region based on Young's classification of growing regions. Looking at the HDD, we can also conclude that it is a "very hot" wine producing area.

Climate Averages

Tables 2-6 below are provided in order to provide an overview of the climate within the proposed Sydney wine region. Comparing the data between the two stations selected in the region, one can conclude that the climate in the Sydney Basin and on the outskirts of the city of Sydney is very similar.

Table 2: Mean daily maximum temperature (°C) in the Sydney wine region

Table 3: Mean daily minimum temperature (°C) in the Sydney wine region

Table 4: Mean monthly rainfall (mm) in the Sydney wine region

Table 5: Mean 9am relative humidity (%)in the Sydney wine region

Table 6: Mean daily hours of sunshine in the Sydney wine region

Note: Shaded areas in tables above represent the growing season where each month has a mean daily minimum temperature greater than 10 °C (i.e. October - April).

Regional Climate Comparison

Using data from the Richmond station to represent the climate in the Sydney region, Table 7 below compares Sydney to other neighbouring wine regions. 

Table 7: Comparative climates of neighbouring wine regions

Region (Station)	MJT 1 (°C)	MAR 2 (°C)	HDD 3 (°C)	Annual Rainfall (mm)	Oct-Apr Rainfall (mm)	RH 4 (%)	SSH 5 (hrs/day)
Lower Hunter (Cessnock)	23.8	12.8	2353	763	539	68.9	n.a.
Sydney (Richmond)	23.5	13.1	2296	810	573	72.3	7.1
Mudgee (Mudgee)	23.3	15.4	2069	676	411	64.3	n.a.
Shoalhaven (Nowra)	20.9	9.9	1886	1135	740	70.3	6.9
Southern Highlands (Bowral)	19.4	12.9	1413	946	577	n.a.	n.a.

Using the information above, we can convert the figures to industry standard words that are used to describe the results. Once converted it can be seen (refer to Table 8) that the Sydney region is very similar to the Lower Hunter. The exception being that Sydney is rated as "very humid" with a relative humidity greater than 70.0%, compared to the Lower Hunter only having a "humid" relative humidity being within the range of 60-70%. 

Table 8: Data from Table 7 used to describe regional information in words

Apart from this similarity, it can be safely concluded that Sydney has a very different climate than the surrounding wine regions of Mudgee, Southern Highlands and the Shoalhaven.

References

Bureau of Meteorology, 2002, Climate Averages for Australian Sites, Retrieved July 31, 2002, from http://www.bom.gov.au/climate/averages/tables/ca_nsw_names.shtml

Smart, Richard E., and Dry, Peter R., 1980, A Climate classification for Australian viticultural regions, The Australian Grapegrower & Winemaker, April issue.

Young, Alan, 1995, Wine is Fun, International Wine Academy, San Francisco, pp81-95.