A frozen étang at the Maison du ParcThe average annual temperature is 11°C. Winter gets 60 days of frost and the average temperature is 4°C. The temperature rarely gets down to -10°C and winters are generally mild (by European standards). Although it can frost into May, on the other hand, the days get warm very early in spring.
The same étang in mid-summer
November to February receives 50-90 hours of sunshine per month, increasing to 250 hours in July. On average there is 2000 hours of sunshine annually. This is quite a lot of sun - compare with London, which averages 1200 hours annually, and Sydney, (although by no means the sunniest Australian city) which gets 2500.
Le Blanc - raining in mid-summer, but still gorgeous
Rainfall is relatively evenly distributed throughout the year, at the rate of 50-65 mm per month. May is the wettest month (but don't let this put you off - it is also the most beautiful month) and July is the driest. April is often dry, however, the rainfall pattern is unpredictable from year to year and considerable variations have been recorded even within the Parc. The average annual rainfall is 700mm. This is considerably less than Sydney's 1200mm, which is generally regarded as rather wet for an Australian city, but on a par with London's 750mm - also generally regarded as a rather wet city. This can be explained by the fact that in London it so frequently drizzles rather than really pelt it down, leading to many more inclement days in order to deliver its quota.
(Note: Much of this information has been cribbed from 'Flore remarquarble du Parc naturel régional de la Brenne' by François Pinet. Any errors are the result of me either misunderstanding or mistranslating the French terminology.)