The only realistic visiting season is October through April, when daytime temperatures are pleasant (20–30°C) and the humidity is low. December and January are the coolest months, with nights cool enough for a light jacket — this is the peak time for the Corniche and the cultural calendar. The annual Saudi National Day on 23 September brings major festivities and fireworks along the seafront.
Summer — June to September — is essentially closed. Daytime temperatures regularly exceed 45°C with crushing humidity from the Gulf, and the city largely retreats indoors to air-conditioned malls and offices. Most outdoor restaurants close their terraces, and the beaches become uncomfortable. Avoid summer travel unless you have a specific reason.
Ramadan reshapes the daily rhythm: most cafes and restaurants close during daylight hours and reopen for iftar at sunset, then stay open well past midnight. Friday is the main day of rest; Saturday is the working week's start.