cant help with temps but check the french weather site la Chaine. We were in Annecy last August and the temp dips when the sun goes behind the mountains at 6-30pm (this was late August). Take a fleece/ jumper and you will be fine. Its a beautiful place.
------------- Thistledown Easter
Nantcol June
Domaine du Verdon Castellane and Etoile d'Argens Frejus Aug
NB the following advice applies to all French mountain regions
It mainly depends if the weather pattern is humid or fresh.
If it's a heatwave, it will be balmy at night, but you'll still end up wanting to put on light trousers and light long sleeved garment - to combat insects as well as chill, especially after about 8pm
I have been to France for the last 9 years always during July and August and only ever take 1 fleece and 1 pair of long trousers (I do take plenty of t shirts and shorts!). I have never needed to use a fan heater and only wear the fleece and long trousers occasionally.
I have stayed in Annecy four times and it is usually warm during the evenings and you'll probably only need a fleece later in the evenings.
You need to watch out for the height of the camp site above sea level, or if you are going up in to the mountains (especially the aguile du midi cable car) or in to the caves at Seminez. The higher up you go or if you go under ground it can get very cold. Once stayed at a campsite in the Verdon Gorge which was 1km above sea level and that was cool in the evenings.
I think you'll find that camp sites around the lake at Annecy will be warm enough during the evening.
I've cycled past it many times, but I always stay at La Ravoire. Both these sites are near each other and it's a lovely area. There are plenty of previous posts on the area if you search by camp site name etc.
We are staying at L'Ideal from 3rd to 10th August following a week just north of Lyon (nr Anse) and are so looking forward to it. We plan to take fleeces given that expect the sun to go down behind the mountains in the evenings...and plan to do a bit of cycling and walking.
I have heard that the site electrics may suffer from the reverse polarity issue - and plan to take along the suggested leads to compensate. Have you heard this, and do you know whether the normal uk type connector pins will fit, or whether a continental adapter is needed ?
Do not know anything about the electrics - we are taking the continental adapter! We have a norfolk lake and a vw transporter pop in for a drink if you see us - we are there ubtil the 6th!
Don't forget to leave a review of the French and other European campsites you have visited!
We were at L'Ideal last August. Had a brill time and plan to return - fab site and fab area.
But
Our connection was reverse polarity, with converter to french plug required. Also, when OH was connecting up, he managed to electrocute himself and trip out the power. Apparently the mains terminals were exposed, so be very careful when connecting up. Luckily he is used to working on far higher voltages and didn't affect him too much. (Prob his own fault for playing - couldn't resist!!)
Have a great time - wish we were going this year, but returning to Auvergne instead.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.