Do you need to know, when is the best time to go to Sierra Leone? Then you should take a look here, what weather you can expect there during the year.
The climate of Sierra Leone is tropical, hot and humid. Summer rainy season is from May to December, winter dry season is from December to April. December and January are the coolest months of the year, but temperatures can be still very high. Lower humidity makes the heat during this period more acceptable than in the rest of the year.
When speaking about the usual weather in this state, the information is relevant for example for these popular places: Banana Islands, Bo, Bonthe, Freetown, Kenema, Koidu, Magburaka, Makeni.
Let's look now what weather you can expect in the area around the capital and in many other cities. The warmest month here is April, the average maximum temperature is 31.4 ℃ (88.52 ℉). The average minimum temperature in this month is 24.9 ℃ (76.82 ℉). The coldest month here is July, the average maximum temperature is 28.2 ℃ (82.76 ℉). The average minimum temperature in this month is 23.6 ℃ (74.48 ℉). 
When travelling to some places in Sierra Leone, always consider the altitude of the the place as well. The highest point here is Loma Mansa (Bintimani) (1948 m) and the lowest point is Atlantic Ocean (0 m). So the differences in altitudes in this country are not negligible and you should expect the weather to be different in places in different altitudes. Keep in mind, that the temperature usually decreases by 1.2 - 1.9 ℃ (2.2 - 3.5 ℉) per 200 m (656 ft), depending on the other conditions. (And we should add, that in the very special condition named thermal inversion even the temperature may be higher in higher altitudes.)
Typical (usual) weather in Sierra Leone in January is this: The average highest temperature in Sierra Leone in January is 29.9 ℃ (85.82 ℉). The average lowest temperature is 24.4 ℃ (75.92 ℉). At the beginning of January you can expect higher temperatures, the average highest temperature is around 30.1 ℃ (86.18 ℉). At the end of January you can expect higher temperatures, the average highest temperature is around 30.4 ℃ (86.72 ℉). The average rainfall is 2.9 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 11:37 (hours and minutes), in the middle of the month 11:40 and at the end of the month 11:45.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Sierra Leone in February is this: The average highest temperature in Sierra Leone in February is 30.9 ℃ (87.62 ℉). The average lowest temperature is 23.9 ℃ (75.02 ℉). At the beginning of February you can expect lower temperatures, the average highest temperature is around 30.4 ℃ (86.72 ℉). At the end of February you can expect lower temperatures, the average highest temperature is around 30.6 ℃ (87.08 ℉). The average rainfall is 4 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 11:45 (hours and minutes), in the middle of the month 11:50 and at the end of the month 11:57.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Sierra Leone in March is this: The average highest temperature in Sierra Leone in March is 30.3 ℃ (86.54 ℉). The average lowest temperature is 24.8 ℃ (76.64 ℉). At the beginning of March you can expect higher temperatures, the average highest temperature is around 30.6 ℃ (87.08 ℉). At the end of March you can expect higher temperatures, the average highest temperature is around 30.85 ℃ (87.53 ℉). The average rainfall is 12.9 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 11:57 (hours and minutes), in the middle of the month 12:04 and at the end of the month 12:11.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Sierra Leone in April is this: The average highest temperature in Sierra Leone in April is 31.4 ℃ (88.52 ℉). The average lowest temperature is 24.9 ℃ (76.82 ℉). At the beginning of April you can expect lower temperatures, the average highest temperature is around 30.85 ℃ (87.53 ℉). At the end of April you can expect lower temperatures, the average highest temperature is around 31.05 ℃ (87.89 ℉). The average rainfall is 47 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 12:11 (hours and minutes), in the middle of the month 12:18 and at the end of the month 12:25.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Sierra Leone in May is this: The average highest temperature in Sierra Leone in May is 30.7 ℃ (87.26 ℉). The average lowest temperature is 24.5 ℃ (76.1 ℉). At the beginning of May you can expect higher temperatures, the average highest temperature is around 31.05 ℃ (87.89 ℉). At the end of May you can expect lower temperatures, the average highest temperature is around 30.55 ℃ (86.99 ℉). The average rainfall is 179.1 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 12:25 (hours and minutes), in the middle of the month 12:30 and at the end of the month 12:35.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Sierra Leone in June is this: The average highest temperature in Sierra Leone in June is 30.4 ℃ (86.72 ℉). The average lowest temperature is 23.6 ℃ (74.48 ℉). At the beginning of June you can expect higher temperatures, the average highest temperature is around 30.55 ℃ (86.99 ℉). At the end of June you can expect lower temperatures, the average highest temperature is around 29.3 ℃ (84.74 ℉). The average rainfall is 316.5 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 12:35 (hours and minutes), in the middle of the month 12:37 and at the end of the month 12:37.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Sierra Leone in July is this: The average highest temperature in Sierra Leone in July is 28.2 ℃ (82.76 ℉). The average lowest temperature is 23.6 ℃ (74.48 ℉). At the beginning of July you can expect higher temperatures, the average highest temperature is around 29.3 ℃ (84.74 ℉). At the end of July you can expect higher temperatures, the average highest temperature is around 28.25 ℃ (82.85 ℉). The average rainfall is 720.1 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 12:37 (hours and minutes), in the middle of the month 12:34 and at the end of the month 12:30.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Sierra Leone in August is this: The average highest temperature in Sierra Leone in August is 28.3 ℃ (82.94 ℉). The average lowest temperature is 23.1 ℃ (73.58 ℉). At the beginning of August you can expect lower temperatures, the average highest temperature is around 28.25 ℃ (82.85 ℉). At the end of August you can expect higher temperatures, the average highest temperature is around 28.85 ℃ (83.93 ℉). The average rainfall is 786.3 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 12:30 (hours and minutes), in the middle of the month 12:25 and at the end of the month 12:18.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Sierra Leone in September is this: The average highest temperature in Sierra Leone in September is 29.4 ℃ (84.92 ℉). The average lowest temperature is 23.6 ℃ (74.48 ℉). At the beginning of September you can expect lower temperatures, the average highest temperature is around 28.85 ℃ (83.93 ℉). At the end of September you can expect higher temperatures, the average highest temperature is around 29.95 ℃ (85.91 ℉). The average rainfall is 493.4 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 12:18 (hours and minutes), in the middle of the month 12:11 and at the end of the month 12:04.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Sierra Leone in October is this: The average highest temperature in Sierra Leone in October is 30.5 ℃ (86.9 ℉). The average lowest temperature is 23.9 ℃ (75.02 ℉). At the beginning of October you can expect lower temperatures, the average highest temperature is around 29.95 ℃ (85.91 ℉). At the end of October you can expect lower temperatures, the average highest temperature is around 30.2 ℃ (86.36 ℉). The average rainfall is 270.9 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 12:04 (hours and minutes), in the middle of the month 11:57 and at the end of the month 11:51.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Sierra Leone in November is this: The average highest temperature in Sierra Leone in November is 29.9 ℃ (85.82 ℉). The average lowest temperature is 24.1 ℃ (75.38 ℉). At the beginning of November you can expect higher temperatures, the average highest temperature is around 30.2 ℃ (86.36 ℉). At the end of November you can expect higher temperatures, the average highest temperature is around 30.1 ℃ (86.18 ℉). The average rainfall is 89.8 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 11:51 (hours and minutes), in the middle of the month 11:45 and at the end of the month 11:40.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Sierra Leone in December is this: The average highest temperature in Sierra Leone in December is 30.3 ℃ (86.54 ℉). The average lowest temperature is 24.1 ℃ (75.38 ℉). At the beginning of December you can expect lower temperatures, the average highest temperature is around 30.1 ℃ (86.18 ℉). At the end of December you can expect lower temperatures, the average highest temperature is around 30.1 ℃ (86.18 ℉). The average rainfall is 15.8 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 11:40 (hours and minutes), in the middle of the month 11:37 and at the end of the month 11:37.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.| Lungi | temperature: 28.1 ℃ (82.58 ℉) | highest temperature: 30.9 ℃ (87.62 ℉) | lowest temperature: 25 ℃ (77 ℉) | rainfall: 15.7mm | rainy days: - |
| Bonthe | temperature: 27.2 ℃ (80.96 ℉) | highest temperature: 31.9 ℃ (89.42 ℉) | lowest temperature: 23.4 ℃ (74.12 ℉) | rainfall: 49.8mm | rainy days: - |
| Bo | temperature: 26.3 ℃ (79.34 ℉) | highest temperature: 32.5 ℃ (90.5 ℉) | lowest temperature: 21.1 ℃ (69.98 ℉) | rainfall: 21.9mm | rainy days: - |
| Kabala | temperature: 24 ℃ (75.2 ℉) | highest temperature: 32.6 ℃ (90.68 ℉) | lowest temperature: 17.2 ℃ (62.96 ℉) | rainfall: 4.7mm | rainy days: - |
| Daru | temperature: 25 ℃ (77 ℉) | highest temperature: 31.4 ℃ (88.52 ℉) | lowest temperature: 20.5 ℃ (68.9 ℉) | rainfall: 36.2mm | rainy days: - |