When to go Budapest ?
High season runs from mid-June to early September. Room rates increase by around 30%. There are three other short "peak" periods: the F1 Grand Prix (in July or August), the Sziget Festival in August and Christmas/New Year. Some Budapest establishments offer mid-season prices just before the start of the high season. Prefer September, October or April and May, when the weather is generally mild, even warm.
Budapest has a temperate continental climate. Winters are generally cold: January is the coldest month of the year with an average temperature of 4°C, and snow is common. Summers are long and hot, even very hot, sometimes stormy. The most pleasant seasons in Budapest are undoubtedly the mid-seasons, with a lot of sunshine. Autumn is often a real Indian summer.