Bahrain, a group of 33 islands, with an area of 707 square kilometres, is situated in the Arabian Gulf, off the east coast of Saudi Arabia. The local time is GMT + 3 hours. The state takes its name from the largest island Bahrain, which is 586.5 square kilometres. It is linked by causeways to Muharraq (international airport) and Sitra (industrial area and tank-farm). There are numerous other tiny islands, but they are mainly uninhabited and are best known for the variety of migrating birds which pass through in spring and autumn. The climate is hot in summer and mild in winter. From November to April is very pleasant, with temperatures from 15 to 24 degrees centigrade. Temperatures are coolest between December and March when northerly winds prevail. From July to September temperatures average 36 degrees centigrade with high humidity .