According to Allcitycodes, Nigeria is a country located in West Africa with a total area of 923,768 km2 and a population of over 200 million people. The terrain consists of several regions including the coastal rainforest in the south, the central savannahs, and the northern semi-arid region. The climate is tropical with two distinct seasons; a dry season from November to March and a wet season from April to October. Average temperatures range between 25-27°C throughout the year with average annual rainfall ranging between 1,000-1,500 mm. The area code for Nigeria is +234. This code is used when dialing from outside Nigeria to any other phone number within it. Additionally, to call a cell phone or landline inside Nigeria from another country you must dial 00 + 234 + area code (without 0) + telephone number. There are currently 6 area codes for different regions across Nigeria; Lagos (01), Abuja (09), Kano (02), Ibadan (03), Kaduna (06) and Port Harcourt (08). For example, to call a phone number in Lagos you would dial 00 + 234 + 01+ telephone number. Nigeria also has mobile networks which are operated by MTN, Glo Mobile, Airtel and 9Mobile which all use GSM networks with 3G/4G coverage available on all networks. To call a mobile device within Nigeria you must dial 00+234+ mobile network prefix + telephone number where the mobile network prefixes are either 8 or 7 depending on whether you are calling an MTN or Glo Mobile/Airtel/9Mobile device respectively. Check physicscat for Nigeria in 2013.