Summer 1976: Hottest on record but even then only had a positive anomaly of
2.3*C, almost only half the anomaly of the very severe 1962-63 winter.

Summer 1995: One of the hottest on record, and still had a positive anomaly
of only 1.9*C".



This is an excellent point. I couldn't have put it better myself. What
this suggests is that we have the scope of much hotter summers than what we
have already experienced.
What do others think?



Your suggestion contradicts the very figures you have put up, which
indicate that the variability of summer temperatures is considerably less than
those of winter temperatures. This is true throughout the mid-latitudes of the
Northern Hemisphere and maybe the Southern as well. Your proposal that we
could expect much hotter summers is based on the idea that the variability of
summer temperatures is as great as that of winter temperatures, and the figures
indicate the well-known fact that this is not the case. Summer 1995 is one of
the hottest on record despite its relatively modest departure from normal
compared to the most extreme winters. That's the climate for you! Why on
earth should you now propose that this should all change and summers should now
exhibit a much greater variability is not clear to me.
Reduced to the basics of synoptic climatology, both extreme winters and
summers are normally cause by persistent circulation anomaly. Since the
temperature differences between different areas of the N. Hemisphere are much
larger in winter than in summer it is hardly surprising that an anomalous
circulation gives rise to greater anomalies in winter than in summer. It is
particuarly true in some of the more continental areas, eg Canada, Russia,
where the standard deviation of mean winter temperatures from year to year is
quite surprisingly high. It's true that they may not notice it as much because
it means the difference between an absolutely bloody awful winter and a merely
cold one, whereas with us, with our temperatures hovering not much above
freezing in winter, a small difference can make a large difference in the
weather.

Best wishes, Tudor Hughes, Warlingham, Surrey