Do you need to know, when is the best time to go to Spain? Then you should take a look here, what weather you can expect there during the year.
The climate of Spain is temperate. You can expect clear and hot summers in interior, but more moderate and cloudy summers along coast. Winters are quite often cloudy and cold in interior, but partly cloudy and cool along coast. In the northern part of the country there is oceanic climate, you can expect snow during winter. In the south eastern part of the country the climate is semiarid. Along the southern and eastern coast the climate is Mediterranean. In the mountains you can expect colder weather.
As Spain has a really huge area, the information below relate mostly only to the area around the capital of this country. To see information about other places, please, choose one of these areas: Andalusia, Balearic Islands, Canary Islands, Central Spain, Eastern Spain, Green Spain, Northern Spain, Spanish North Africa.
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 August, the average maximum temperature is 32.1 ℃ (89.78 ℉). The average minimum temperature in this month is 19.2 ℃ (66.56 ℉). The coldest month here is December, the average maximum temperature is 10.1 ℃ (50.18 ℉). The average minimum temperature in this month is 3.8 ℃ (38.84 ℉). The most rainy month here is May, the average number of rainy days is 10.4. The least rainy month here is July, the average number of rainy days is 2.6. 
When travelling to some places in Spain, always consider the altitude of the the place as well. The highest point here is Pico de Teide (Tenerife) on Canary Islands (3718 m) and the lowest point is Atlantic Ocean (0 m). So there are huge differences in altitudes in this country and the weather is very different in them therefore. 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 Spain in January is this: The average highest temperature in Spain in January is 10.2 ℃ (50.36 ℉). The average lowest temperature is 2.9 ℃ (37.22 ℉). At the beginning of January you can expect lower temperatures, the average highest temperature is around 10.15 ℃ (50.27 ℉). At the end of January you can expect higher temperatures, the average highest temperature is around 11.2 ℃ (52.16 ℉). The average number of rainy days in January is 8.2. The average rainfall is 33.4 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 9:20 (hours and minutes), in the middle of the month 9:36 and at the end of the month 10:04.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 Spain in February is this: The average highest temperature in Spain in February is 12.2 ℃ (53.96 ℉). The average lowest temperature is 3.9 ℃ (39.02 ℉). At the beginning of February you can expect lower temperatures, the average highest temperature is around 11.2 ℃ (52.16 ℉). At the end of February you can expect higher temperatures, the average highest temperature is around 14.35 ℃ (57.83 ℉). The average number of rainy days in February is 7.8. The average rainfall is 34.8 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 10:04 (hours and minutes), in the middle of the month 10:38 and at the end of the month 11:17.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 Spain in March is this: The average highest temperature in Spain in March is 16.5 ℃ (61.7 ℉). The average lowest temperature is 6.4 ℃ (43.52 ℉). At the beginning of March you can expect lower temperatures, the average highest temperature is around 14.35 ℃ (57.83 ℉). At the end of March you can expect higher temperatures, the average highest temperature is around 17.4 ℃ (63.32 ℉). The average number of rainy days in March is 6.5. The average rainfall is 24.9 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 11:17 (hours and minutes), in the middle of the month 11:57 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 Spain in April is this: The average highest temperature in Spain in April is 18.3 ℃ (64.94 ℉). The average lowest temperature is 8 ℃ (46.4 ℉). At the beginning of April you can expect lower temperatures, the average highest temperature is around 17.4 ℃ (63.32 ℉). At the end of April you can expect higher temperatures, the average highest temperature is around 20.1 ℃ (68.18 ℉). The average number of rainy days in April is 10.3. The average rainfall is 45.6 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 12:37 (hours and minutes), in the middle of the month 13:16 and at the end of the month 13:53.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 Spain in May is this: The average highest temperature in Spain in May is 21.9 ℃ (71.42 ℉). The average lowest temperature is 11.3 ℃ (52.34 ℉). At the beginning of May you can expect lower temperatures, the average highest temperature is around 20.1 ℃ (68.18 ℉). At the end of May you can expect higher temperatures, the average highest temperature is around 24.8 ℃ (76.64 ℉). The average number of rainy days in May is 10.4. The average rainfall is 49.7 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 13:53 (hours and minutes), in the middle of the month 14:25 and at the end of the month 14:49.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 Spain in June is this: The average highest temperature in Spain in June is 27.7 ℃ (81.86 ℉). The average lowest temperature is 16 ℃ (60.8 ℉). At the beginning of June you can expect lower temperatures, the average highest temperature is around 24.8 ℃ (76.64 ℉). At the end of June you can expect higher temperatures, the average highest temperature is around 29.65 ℃ (85.37 ℉). The average number of rainy days in June is 5.7. The average rainfall is 20.8 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 14:49 (hours and minutes), in the middle of the month 15:02 and at the end of the month 15:01.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 Spain in July is this: The average highest temperature in Spain in July is 31.6 ℃ (88.88 ℉). The average lowest temperature is 19.6 ℃ (67.28 ℉). At the beginning of July you can expect lower temperatures, the average highest temperature is around 29.65 ℃ (85.37 ℉). At the end of July you can expect higher temperatures, the average highest temperature is around 31.85 ℃ (89.33 ℉). The average number of rainy days in July is 2.6. The average rainfall is 11.7 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 15:01 (hours and minutes), in the middle of the month 14:48 and at the end of the month 14:23.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, especially in mountains.Typical (usual) weather in Spain in August is this: The average highest temperature in Spain in August is 32.1 ℃ (89.78 ℉). The average lowest temperature is 19.2 ℃ (66.56 ℉). At the beginning of August you can expect lower temperatures, the average highest temperature is around 31.85 ℃ (89.33 ℉). At the end of August you can expect lower temperatures, the average highest temperature is around 29.6 ℃ (85.28 ℉). The average number of rainy days in August is 2.8. The average rainfall is 9.7 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 14:23 (hours and minutes), in the middle of the month 13:52 and at the end of the month 13:15.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, especially in mountains.Typical (usual) weather in Spain in September is this: The average highest temperature in Spain in September is 27.1 ℃ (80.78 ℉). The average lowest temperature is 15.5 ℃ (59.9 ℉). At the beginning of September you can expect higher temperatures, the average highest temperature is around 29.6 ℃ (85.28 ℉). At the end of September you can expect lower temperatures, the average highest temperature is around 23.6 ℃ (74.48 ℉). The average number of rainy days in September is 5.4. The average rainfall is 22.6 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 13:15 (hours and minutes), in the middle of the month 12:36 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 Spain in October is this: The average highest temperature in Spain in October is 20.1 ℃ (68.18 ℉). The average lowest temperature is 10.9 ℃ (51.62 ℉). At the beginning of October you can expect higher temperatures, the average highest temperature is around 23.6 ℃ (74.48 ℉). At the end of October you can expect lower temperatures, the average highest temperature is around 16.8 ℃ (62.24 ℉). The average number of rainy days in October is 9.3. The average rainfall is 60.2 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 11:57 (hours and minutes), in the middle of the month 11:17 and at the end of the month 10:39.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 Spain in November is this: The average highest temperature in Spain in November is 13.5 ℃ (56.3 ℉). The average lowest temperature is 6.5 ℃ (43.7 ℉). At the beginning of November you can expect higher temperatures, the average highest temperature is around 16.8 ℃ (62.24 ℉). At the end of November you can expect lower temperatures, the average highest temperature is around 11.8 ℃ (53.24 ℉). The average number of rainy days in November is 9.1. The average rainfall is 57.3 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 10:39 (hours and minutes), in the middle of the month 10:05 and at the end of the month 9:37.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 Spain in December is this: The average highest temperature in Spain in December is 10.1 ℃ (50.18 ℉). The average lowest temperature is 3.8 ℃ (38.84 ℉). At the beginning of December you can expect higher temperatures, the average highest temperature is around 11.8 ℃ (53.24 ℉). At the end of December you can expect higher temperatures, the average highest temperature is around 10.15 ℃ (50.27 ℉). The average number of rainy days in December is 9.9. The average rainfall is 51.2 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 9:37 (hours and minutes), in the middle of the month 9:20 and at the end of the month 9:17.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.