Do you need to know, when is the best time to go to Luxembourg? Then you should take a look here, what weather you can expect there during the year.
The climate of Luxembourg is continental. You can expect mild winters, and cool summers. Rainfall is relatively high here. In the north the weather is more unstable than in the south.
When speaking about the usual weather in this state, the information is relevant for example for these popular places: Beaufort, Clervaux, Consdorf, Diekirch, Echternach, Esch sur Sûre, Ettelbruck, Grevenmacher, Guttland, Land of the Red Rocks, Larochette, Luxembourg, Luxembourgian Ardennes, Mersch, Mondorf les Bains, Moselle District, Mullerthal, Remich, Schengen, Troisvierges, Vianden, Wasserbillig, Wiltz.
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 July, the average maximum temperature is 21.9 ℃ (71.42 ℉). The average minimum temperature in this month is 12.1 ℃ (53.78 ℉). The coldest month here is January, the average maximum temperature is 2.5 ℃ (36.5 ℉). The average minimum temperature in this month is -2.1 ℃ (28.22 ℉). The most rainy month here is January, the average number of rainy days is 17.9. The least rainy month here is July, the average number of rainy days is 12.4. 
Typical (usual) weather in Luxembourg in January is this: The average highest temperature in Luxembourg in January is 2.5 ℃ (36.5 ℉). The average lowest temperature is -2.1 ℃ (28.22 ℉). At the beginning of January you can expect higher temperatures, the average highest temperature is around 3.05 ℃ (37.49 ℉). At the end of January you can expect higher temperatures, the average highest temperature is around 3.45 ℃ (38.21 ℉). The average number of rainy days in January is 17.9. The average rainfall is 71.4 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 8:12 (hours and minutes), in the middle of the month 8:36 and at the end of the month 9:16.These numbers above are valid primarily for the capital and the area around it.
Typical (usual) weather in Luxembourg in February is this: The average highest temperature in Luxembourg in February is 4.4 ℃ (39.92 ℉). The average lowest temperature is -1.6 ℃ (29.12 ℉). At the beginning of February you can expect lower temperatures, the average highest temperature is around 3.45 ℃ (38.21 ℉). At the end of February you can expect higher temperatures, the average highest temperature is around 6.2 ℃ (43.16 ℉). The average number of rainy days in February is 14.9. The average rainfall is 60.9 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 9:16 (hours and minutes), in the middle of the month 10:05 and at the end of the month 10:59.These numbers above are valid primarily for the capital and the area around it.Typical (usual) weather in Luxembourg in March is this: The average highest temperature in Luxembourg in March is 8 ℃ (46.4 ℉). The average lowest temperature is 0.8 ℃ (33.44 ℉). At the beginning of March you can expect lower temperatures, the average highest temperature is around 6.2 ℃ (43.16 ℉). At the end of March you can expect higher temperatures, the average highest temperature is around 10.25 ℃ (50.45 ℉). The average number of rainy days in March is 16.6. The average rainfall is 68.7 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 10:59 (hours and minutes), in the middle of the month 11:54 and at the end of the month 12:50.These numbers above are valid primarily for the capital and the area around it.Typical (usual) weather in Luxembourg in April is this: The average highest temperature in Luxembourg in April is 12.5 ℃ (54.5 ℉). The average lowest temperature is 3.6 ℃ (38.48 ℉). At the beginning of April you can expect lower temperatures, the average highest temperature is around 10.25 ℃ (50.45 ℉). At the end of April you can expect higher temperatures, the average highest temperature is around 14.65 ℃ (58.37 ℉). The average number of rainy days in April is 15.9. The average rainfall is 61.1 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 12:50 (hours and minutes), in the middle of the month 13:44 and at the end of the month 14:36.These numbers above are valid primarily for the capital and the area around it.
Typical (usual) weather in Luxembourg in May is this: The average highest temperature in Luxembourg in May is 16.8 ℃ (62.24 ℉). The average lowest temperature is 7.4 ℃ (45.32 ℉). At the beginning of May you can expect lower temperatures, the average highest temperature is around 14.65 ℃ (58.37 ℉). At the end of May you can expect higher temperatures, the average highest temperature is around 18.3 ℃ (64.94 ℉). The average number of rainy days in May is 16. The average rainfall is 79.7 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 14:36 (hours and minutes), in the middle of the month 15:22 and at the end of the month 15:57.These numbers above are valid primarily for the capital and the area around it.Typical (usual) weather in Luxembourg in June is this: The average highest temperature in Luxembourg in June is 19.8 ℃ (67.64 ℉). The average lowest temperature is 10.4 ℃ (50.72 ℉). At the beginning of June you can expect lower temperatures, the average highest temperature is around 18.3 ℃ (64.94 ℉). At the end of June you can expect higher temperatures, the average highest temperature is around 20.85 ℃ (69.53 ℉). The average number of rainy days in June is 14.5. The average rainfall is 81.5 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 15:57 (hours and minutes), in the middle of the month 16:16 and at the end of the month 16:15.These numbers above are valid primarily for the capital and the area around it.Typical (usual) weather in Luxembourg in July is this: The average highest temperature in Luxembourg in July is 21.9 ℃ (71.42 ℉). The average lowest temperature is 12.1 ℃ (53.78 ℉). At the beginning of July you can expect lower temperatures, the average highest temperature is around 20.85 ℃ (69.53 ℉). At the end of July you can expect lower temperatures, the average highest temperature is around 21.7 ℃ (71.06 ℉). The average number of rainy days in July is 12.4. The average rainfall is 68.2 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 16:15 (hours and minutes), in the middle of the month 15:55 and at the end of the month 15:19.These numbers above are valid primarily for the capital and the area around it.Typical (usual) weather in Luxembourg in August is this: The average highest temperature in Luxembourg in August is 21.5 ℃ (70.7 ℉). The average lowest temperature is 12.2 ℃ (53.96 ℉). At the beginning of August you can expect higher temperatures, the average highest temperature is around 21.7 ℃ (71.06 ℉). At the end of August you can expect lower temperatures, the average highest temperature is around 19.8 ℃ (67.64 ℉). The average number of rainy days in August is 13.2. The average rainfall is 72.6 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 15:19 (hours and minutes), in the middle of the month 14:34 and at the end of the month 13:43.These numbers above are valid primarily for the capital and the area around it.Typical (usual) weather in Luxembourg in September is this: The average highest temperature in Luxembourg in September is 18.1 ℃ (64.58 ℉). The average lowest temperature is 9.5 ℃ (49.1 ℉). At the beginning of September you can expect higher temperatures, the average highest temperature is around 19.8 ℃ (67.64 ℉). At the end of September you can expect lower temperatures, the average highest temperature is around 15.55 ℃ (59.99 ℉). The average number of rainy days in September is 12.6. The average rainfall is 70.2 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 13:43 (hours and minutes), in the middle of the month 12:49 and at the end of the month 11:54.These numbers above are valid primarily for the capital and the area around it.Typical (usual) weather in Luxembourg in October is this: The average highest temperature in Luxembourg in October is 13 ℃ (55.4 ℉). The average lowest temperature is 5.8 ℃ (42.44 ℉). At the beginning of October you can expect higher temperatures, the average highest temperature is around 15.55 ℃ (59.99 ℉). At the end of October you can expect lower temperatures, the average highest temperature is around 9.9 ℃ (49.82 ℉). The average number of rainy days in October is 14.3. The average rainfall is 74.5 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 11:54 (hours and minutes), in the middle of the month 10:59 and at the end of the month 10:06.These numbers above are valid primarily for the capital and the area around it.Typical (usual) weather in Luxembourg in November is this: The average highest temperature in Luxembourg in November is 6.8 ℃ (44.24 ℉). The average lowest temperature is 1.4 ℃ (34.52 ℉). At the beginning of November you can expect higher temperatures, the average highest temperature is around 9.9 ℃ (49.82 ℉). At the end of November you can expect lower temperatures, the average highest temperature is around 5.2 ℃ (41.36 ℉). The average number of rainy days in November is 16.5. The average rainfall is 83.3 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 10:06 (hours and minutes), in the middle of the month 9:17 and at the end of the month 8:37.These numbers above are valid primarily for the capital and the area around it.Typical (usual) weather in Luxembourg in December is this: The average highest temperature in Luxembourg in December is 3.6 ℃ (38.48 ℉). The average lowest temperature is -1.1 ℃ (30.02 ℉). At the beginning of December you can expect higher temperatures, the average highest temperature is around 5.2 ℃ (41.36 ℉). At the end of December you can expect lower temperatures, the average highest temperature is around 3.05 ℃ (37.49 ℉). The average number of rainy days in December is 16.7. The average rainfall is 78.5 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 8:37 (hours and minutes), in the middle of the month 8:13 and at the end of the month 8:08.These numbers above are valid primarily for the capital and the area around it.