Do you need to know, when is the best time to go to Seychelles? Then you should take a look here, what weather you can expect there during the year.
The climate of Seychelles is tropical marine. You can always expect warm weather without extremes. There is a cooler season during southeast monsoon from late May to September, and warmer season during northwest monsoon from March to May.
When speaking about the usual weather in this state, the information is relevant for example for these popular places: Beau Vallon, La Digue, Mahé, Outer Seychelles, Praslin, Silhouette Island, Victoria.
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 March, the average maximum temperature is 31.9 ℃ (89.42 ℉). The average minimum temperature in this month is 25.6 ℃ (78.08 ℉). The coldest month here is August, the average maximum temperature is 28.2 ℃ (82.76 ℉). The average minimum temperature in this month is 24.5 ℃ (76.1 ℉). The most rainy month here is December, the average number of rainy days is 20.7. The least rainy month here is February, the average number of rainy days is 12.7. 
When travelling to some places in Seychelles, always consider the altitude of the the place as well. The highest point here is Morne Seychellois (905 m) and the lowest point is Indian Ocean (0 m). So there are not big differences in altitudes in this country. But the altitude affects the weather even so. 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 Seychelles in January is this: The average highest temperature in Seychelles in January is 30.7 ℃ (87.26 ℉). The average lowest temperature is 24.6 ℃ (76.28 ℉). At the beginning of January you can expect higher temperatures, the average highest temperature is around 30.95 ℃ (87.71 ℉). At the end of January you can expect higher temperatures, the average highest temperature is around 31 ℃ (87.8 ℉). The average number of rainy days in January is 19.6. The average rainfall is 409.1 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 12:23 (hours and minutes), in the middle of the month 12:21 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.Typical (usual) weather in Seychelles in February is this: The average highest temperature in Seychelles in February is 31.3 ℃ (88.34 ℉). The average lowest temperature is 24.9 ℃ (76.82 ℉). At the beginning of February you can expect lower temperatures, the average highest temperature is around 31 ℃ (87.8 ℉). At the end of February you can expect higher temperatures, the average highest temperature is around 31.6 ℃ (88.88 ℉). The average number of rainy days in February is 12.7. The average rainfall is 247.1 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 12:18 (hours and minutes), in the middle of the month 12:15 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.Typical (usual) weather in Seychelles in March is this: The average highest temperature in Seychelles in March is 31.9 ℃ (89.42 ℉). The average lowest temperature is 25.6 ℃ (78.08 ℉). At the beginning of March you can expect lower temperatures, the average highest temperature is around 31.6 ℃ (88.88 ℉). At the end of March you can expect lower temperatures, the average highest temperature is around 31.55 ℃ (88.79 ℉). The average number of rainy days in March is 15.1. The average rainfall is 199 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 12:07 and at the end of the month 12:03.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.Typical (usual) weather in Seychelles in April is this: The average highest temperature in Seychelles in April is 31.2 ℃ (88.16 ℉). The average lowest temperature is 26.2 ℃ (79.16 ℉). At the beginning of April you can expect higher temperatures, the average highest temperature is around 31.55 ℃ (88.79 ℉). At the end of April you can expect lower temperatures, the average highest temperature is around 30.9 ℃ (87.62 ℉). The average number of rainy days in April is 16.2. The average rainfall is 185.2 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 12:03 (hours and minutes), in the middle of the month 12:00 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.Typical (usual) weather in Seychelles in May is this: The average highest temperature in Seychelles in May is 30.6 ℃ (87.08 ℉). The average lowest temperature is 25.3 ℃ (77.54 ℉). At the beginning of May you can expect higher temperatures, the average highest temperature is around 30.9 ℃ (87.62 ℉). At the end of May you can expect lower temperatures, the average highest temperature is around 29.75 ℃ (85.55 ℉). The average number of rainy days in May is 16. The average rainfall is 163 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 11:54 and at the end of the month 11:52.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.Typical (usual) weather in Seychelles in June is this: The average highest temperature in Seychelles in June is 28.9 ℃ (84.02 ℉). The average lowest temperature is 25.6 ℃ (78.08 ℉). At the beginning of June you can expect higher temperatures, the average highest temperature is around 29.75 ℃ (85.55 ℉). At the end of June you can expect higher temperatures, the average highest temperature is around 29.15 ℃ (84.47 ℉). The average number of rainy days in June is 17. The average rainfall is 118.3 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 11:52 (hours and minutes), in the middle of the month 11:51 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.Typical (usual) weather in Seychelles in July is this: The average highest temperature in Seychelles in July is 29.4 ℃ (84.92 ℉). The average lowest temperature is 24.3 ℃ (75.74 ℉). At the beginning of July you can expect lower temperatures, the average highest temperature is around 29.15 ℃ (84.47 ℉). At the end of July you can expect lower temperatures, the average highest temperature is around 28.8 ℃ (83.84 ℉). The average number of rainy days in July is 16.9. 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 11:52 and at the end of the month 11:54.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.Typical (usual) weather in Seychelles in August is this: The average highest temperature in Seychelles in August is 28.2 ℃ (82.76 ℉). The average lowest temperature is 24.5 ℃ (76.1 ℉). At the beginning of August you can expect higher temperatures, the average highest temperature is around 28.8 ℃ (83.84 ℉). At the end of August you can expect higher temperatures, the average highest temperature is around 28.6 ℃ (83.48 ℉). The average number of rainy days in August is 16.4. The average rainfall is 123.4 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 11:54 (hours and minutes), in the middle of the month 11:57 and at the end of the month 12:00.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.Typical (usual) weather in Seychelles in September is this: The average highest temperature in Seychelles in September is 29 ℃ (84.2 ℉). The average lowest temperature is 25.3 ℃ (77.54 ℉). At the beginning of September you can expect lower temperatures, the average highest temperature is around 28.6 ℃ (83.48 ℉). At the end of September you can expect higher temperatures, the average highest temperature is around 29.55 ℃ (85.19 ℉). The average number of rainy days in September is 16.6. The average rainfall is 164.2 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 12:00 (hours and minutes), in the middle of the month 12:04 and at the end of the month 12:07.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.Typical (usual) weather in Seychelles in October is this: The average highest temperature in Seychelles in October is 30.1 ℃ (86.18 ℉). The average lowest temperature is 24.7 ℃ (76.46 ℉). At the beginning of October you can expect lower temperatures, the average highest temperature is around 29.55 ℃ (85.19 ℉). At the end of October you can expect lower temperatures, the average highest temperature is around 29.95 ℃ (85.91 ℉). The average number of rainy days in October is 16. 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 12:07 (hours and minutes), in the middle of the month 12:11 and at the end of the month 12:15.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.Typical (usual) weather in Seychelles in November is this: The average highest temperature in Seychelles in November is 29.8 ℃ (85.64 ℉). 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 29.95 ℃ (85.91 ℉). At the end of November you can expect higher temperatures, the average highest temperature is around 30.5 ℃ (86.9 ℉). The average number of rainy days in November is 16. The average rainfall is 190.2 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 12:15 (hours and minutes), in the middle of the month 12:18 and at the end of the month 12:21.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.Typical (usual) weather in Seychelles in December is this: The average highest temperature in Seychelles in December is 31.2 ℃ (88.16 ℉). The average lowest temperature is 24 ℃ (75.2 ℉). At the beginning of December you can expect lower temperatures, the average highest temperature is around 30.5 ℃ (86.9 ℉). At the end of December you can expect lower temperatures, the average highest temperature is around 30.95 ℃ (87.71 ℉). The average number of rainy days in December is 20.7. The average rainfall is 306.8 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 12:21 (hours and minutes), in the middle of the month 12:23 and at the end of the month 12:23.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.