When travelling, it's generally smart to pack in preparation for rain or any other conditions that may arise. The rainfall in Bristol is roughly greater than that of Dnepropetrovsk. You can assume this to be the case over the next 19 days.
Expect the weather to be around 28 °C on average in July. As the temperature peaks, try to get your plans done early, as flight price and availability will have an impact on your travels. The climate in Dnepropetrovsk is generally hotter than in Bristol.