Saudi Arabia is a desert, so its climate is dry and hot during the day, but generally cool at night. Coastal areas are cooler during the day but only slightly more, and instead of extreme heat, there’s extreme humidity.
It rains a few times every year across the country, and there is a risk of severe flooding when it does.
Summer in the inland zone can be quite hot, rising up to 55°C (131°F) in some areas. It’s essential to carry drinking water at all times.
In winter, temperatures drop and the weather becomes mild during the day and cold at night. Sandstorms usually precede seasonal changes, and these can last a few weeks.
Riyadh is dry and hot, but annual rainfall is about four inches (102mm) of rain a year, most of it between January and May. In summer, temperatures can go up to 131°F (55°C). At night in winter, temperatures can fall below freezing. The best months in Riyadh, when days are mild (21°C on average) and nights are cool, are from October to May.
A coastal city, Jeddah is very humid. Its winters are mild, with heavy thunderstorms and rain usually falling in December. Its summer temperatures, on the other hand, are quite hot, often reaching 40°C (104°F).
Mecca is an inland city about 80 kms from the sea, and at 920 feet (280 meters) above sea level.
Mecca has hot summer days (average highs of 42°C/107°F) and mild summer nights (average lows of 30°C/86°F). In winter, average temperatures are between 30°C/86°F and 18°C/64°F) at night. Thunderstorms and hail can occur during the winter months.
Sand and dust storms are common throughout the year but occur more frequently during summer. Flash floods can also occur in winter despite low rainfall.
At 180 km inland from the sea, Medina’s temperature averages throughout the year are between a high of 26°C (79°F) and a low of 15°C (59°F ) in winter; and between 42°C 107°F) and 30°C (86°F) in summer. On average, there’s 40 inches (102 cm) of rain per year.
Dammam, Khobar and Dhahran in the Eastern Province have an arid climate. Winter temperatures are mild, ranging from 21 °C (59 °F) in the daytime to 11 °C (52°F) at night. Thunderstorms are common in winter, but rainfall is sparse. Summer weather is extremely hot, often reaching 50°C (122°F), though the average summer temperatures are 40°C (104°F) in the day and 26°C (79°F) at night. Dust storms are frequent in summer.