[Petrochemicals (OP)]

the example already given of temperature difference in march this year illustrates an extreme drop

So now, we are not talking about the temperature on a particular day, but you are looking at a particular month in a particular year.
- For example, in the week around 20th April, there is a sustained period with a large temperature range, indicating clear skies, while the 2nd April has a very small range, suggesting overcast conditions that day
- So this is still not a generic statement about Spring and Summer, that could be applied in the same place in different years, let alone different places in different years
- If it has no predictive power, it is an anecdote, rather than a hypothesis

We are looking at why heat is dissipated so much more quickly in spring than summer. As posted as reply to Alan, we ar having some exceptional weather in the 2 most recent springs. The heat does not seem to build in the way that it does during the summer months. The example of the desert seems to be the  best fit

[Petrochemicals (OP)]

It's very cold tonight yet dry, the air is blowing from the north. I suppose the night time temperature has something to do with where the air blows from, the higher low atmosphere dictating whether the hot air rises or not.