Normandy is at its best between April and October. The summer months are busy with village festivals, fairs and horse racing, and some beaches fill with Parisians in August. Hotspots such as Honfleur can get very crowded, but inland regions such as La Perche are idyllic. If you have a free choice, we particularly like autumn, when trees are full of colour, the apple harvest gets underway, there are few tourists and plenty of coquilles st jacques (fresh local scallops). Spring is also lovely, with the Coutances jazz festival in May and the D-day anniversary commemorations in June.
In terms of climate, it's similar to southern England - some people call Normandy the French Devon. So be prepared for rain at any time of year, but hope for sun - and you'll probably get a mixture.
NB, please do not rely solely on this information for your travel plans.
NORMANDY: BY AIR
From the UK: carriers include Ryanair, City Jet (operated by Air France) and Aurigny.
Alternatively you can fly to Paris, then take the train (see below).
By train from Paris: There is a train service to northern Normandy from Paris St Lazare (1.5 - 3 hours) and to southern Normandy from Montparnasse (1-2 hours). You can also take the Eurostar from London to Paris.
By ferry from the UK: Most people drive to Normandy and there's a choice of ferry routes. AFerry.co.uk offer a full list of up-to-date ferry routes from the UK to Normandy. Or you can cross from Dover to Calais via the Eurotunnel and then drive to Normandy.