You'll likely spend much of your trip indoors, but if you're planning to venture beyond the casino, taking a look at local weather data can help you. The hottest months are usually January and December, with an average temperature of 29°C, while the coldest months are August and July, with an average of 26°C. The rainiest months in Lagos are June, July, September and October, with each month seeing an average of 251 mm of rainfall.