So I think this year we will be taking a greater look at the effect of UHI on the averages in the big smokes of the country, particularly Melbourne, Sydney and Brisbane. We see a large temp variance every summer and spring across the metropolitan areas, but have been told many a time that the difference is not that great.
So here we will be taking down the obs and data from days and more particularly nights, where there is a large scale difference over a small area.
Sites to be looked at are Melbourne CBD, Tullamarine, Essendon, Laverton, Coldstream, Scoresby and Cerebus.
I think those stations give a good depth of analysis for the season and we will see how big the part of UHI really is!
Of course we can all do our own real life experiment by just driving our cars from rural areas into urban, and noting the car's thermometer readings changing (if the car has one of course).
I well remember driving home from a friends house out in the countryside in a river valley at night time. My car would have a crust of ice on it when I left his house and the car's thermometer would be reading 0c or -1c. As I reached the outer fringes of my home town the temp would rise above freezing and gradually increase as I drove into town centre it would be up to +3c to +4c. By the time I reached my home on the other side of town it would fall back to +1c to +2c. So a difference of 3c to 5c from rural to urban locations.
The difference during the daytime was never so great, maybe 1c to 2c depending on the weather conditions at the time. Clear conditions at any time of day almost always lead to a bigger difference than cloudy or rainy conditions which evened things out.
I think the interesting days will be the ones that are seabreeze impacted. So where the CBD is say 27C and the inland suburbs are around 35-36 in light offshore winds. It is those days you find by 10pm, that the inland suburbs are cooler than CBD!