Urban verses Un-urban Areas

[NZ Thunderstorm Soc]

I thought I would start up a new topic, which might define urban areas temperature readings as compared to un-urban areas like airports, AWS and other areas where town buildings, concrete and paved areas are not closely located where official readings are recorded.

[NZstorm]

Urban heat Islands show up at night. That's certainly the case in Auckland.

[cbm]

My observation is that the urban climate is dictated by solar radiation a lot more than properly exposed sites. This presumably is because there is more shelter from general wind flows that will "mix out", and there are more surfaces/materials to absorb and retain heat from the solar radiation.
Going on airport data, today was the warmest of this current sequence, yet I “only” got to 28.6 today, when airport got to at least 27.5 where as I got to 29.8 on Monday when airport only got to 26.
Monday had full solar radiation all day, where as today only had it in spells. Noticed this past winter that there was a spell from May 30th to early July when my overnight mins were quite close to the airport’s, but once got to end of July and onward s the days got a bit longer, the solar radiation stronger, and I saw no more below 0 air temps even through airport was still getting down to about -1.0C on a handful of days.

[Richard]

I wonder how much influence has the urban development of Rolleston west of CHCH had on the summer sea breezes?, the town a prime example of what Tony and myself pointed out yesterday in General January Weather - large houses on small sections, dark roofs, little room for trees, black roads. Has the town growth influenced increased the inflow due to the urban heat Island effect?, quite likely!. The town is situated though where it could effect both the SE onshore winds south of Banks Peninsula or the E-NE to the north. It would be interesting to know whether the sea breezes have increased over the years due the urban sprawl of both Christchurch and Rolleston?