The first thing we would like to note in order to calm all parents who might still be hesitating: Lake Balaton isa body of living water, so you can take your 4- or 5-month-old baby in with you, if your temperament and the water's temperature allow. You can also find beaches with pools (e.g. in Balatonlelle, Keszthely, and Balatonfüred), where you can decide between the options, depending on your notion of safety.
You might want to remember that the gravel on promenades is often treated with herbicides - and one of the favourite past-times of this age group is to collect and taste pebbles. Do not allow your toddler to collect stones on beach promenades or ask the buffet staff about it - they always know everything.
If you are by the water, it means you have already conquered the first obstacle: transport. It is by no means an easy task to reach the shore with a pram, especially not from the other side of the railway and the main road. The majority of the beaches, piers and shores are toddler-friendly, but getting there is less so. If you can, go by car or bike - otherwise you might have to fight yourself across the rails, go through the insanity training that the combination of the stairs of the pedestrian bridge over the railways and the pram pose, or make a huge detour to find a suitable crossing to the shore-side.
In the case of children already on their own feet, the question of the playground is quintessential. These have had to be EU-conform since 2009, but only about half of them comply with the relevant regulations. You will find outdated structures also at Lake Balaton, and this means a greater risk of injury. You should look for central locations and larger beaches, where superb, modern and safe playgrounds await the little ones.
If you want your child to be safe also in the water, choose a beach with a a kid-friendly lido, where the sandy/grassy shore descends into water gradually. We have good news: you have an increasing number of options. Some examples: they are already constructing the lido inBalatonfűzfő, Szepezd and Fonyód; they are ready in Balatonlelle, Balatonfüred, Balatonfenyves, and Vonyarcvashegy, and Balatonudvari is about to join the queue. You can let your kids roam the gently sloping, sandy beaches freely: they will entertain themselves by playing with the mud in the shallow water, while you are sunbathing or swimming.
Always apply sunscreen onto the skin of your baby, but do not waste money on products with SPF 30+. The excessive SPF value prevents vitamin D from entering the skin and the protective value of SPF 50 is only 1.5% higher that that of SPF 30. But it is all the more expensive.