Do you need to know, when is the best time to go to Iceland? Then you should take a look here, what weather you can expect there during the year.
The climate of Iceland is subarctic, but it is moderated by North Atlantic Current. So it is warmer than you would expect here. You can expect relatively mild, but windy winters, and quite damp, cool summers. The weather in Iceland can be quite unstable.
When speaking about the usual weather in this state, the information is relevant for example for these popular places: Akureyri, Blue Lagoon, Blönduós, Borgarnes, East Iceland, Egilsstaðir, Eyrarbakki, Hafnarfjörður, Hella, Hellissandur, Hveragerði, Höfn, Húsavík, Interior, Jökulsárlón, Keflavík, Kirkjubæjarklaustur, Kópavogur, Landmannalaugar, Mývatn, North Iceland, Raufarhöfn, Reykjahlíð, Reykjavík, Selfoss, Seyðisfjörður, Skagafjörður, Skútustaðir, Snæfellsjökull National Park, South Iceland, Southwest Iceland, Stokkseyri, Stykkishólmur, Suðureyri, Súðavík, Upcountry Árnessýsla, Vatnajökull National Park, Vestmannaeyjar, Vík í Mýrdal, West Iceland, Westfjords, Ísafjörður, Þingvellir National Park.
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 13.6 ℃ (56.48 ℉). The average minimum temperature in this month is 8.6 ℃ (47.48 ℉). The coldest month here is January, the average maximum temperature is 2.1 ℃ (35.78 ℉). The average minimum temperature in this month is -2.8 ℃ (26.96 ℉). The most rainy month here is October, the average number of rainy days is 14.7. The least rainy month here is May, the average number of rainy days is 9.6. 
When travelling to some places in Iceland, always consider the altitude of the the place as well. The highest point here is Hvannadalshnukur (2110 m) and the lowest point is Atlantic Ocean (0 m). So there are quite big differences in altitudes in this country, so you can expect the weather to be different in different altitudes as well. 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 Iceland in January is this: The average highest temperature in Iceland in January is 2.1 ℃ (35.78 ℉). The average lowest temperature is -2.8 ℃ (26.96 ℉). At the beginning of January you can expect higher temperatures, the average highest temperature is around 2.25 ℃ (36.05 ℉). At the end of January you can expect higher temperatures, the average highest temperature is around 2.5 ℃ (36.5 ℉). The average number of rainy days in January is 13.6. The average rainfall is 74.7 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 4:21 (hours and minutes), in the middle of the month 5:24 and at the end of the month 6:53.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 Iceland in February is this: The average highest temperature in Iceland in February is 2.9 ℃ (37.22 ℉). The average lowest temperature is -1.9 ℃ (28.58 ℉). At the beginning of February you can expect lower temperatures, the average highest temperature is around 2.5 ℃ (36.5 ℉). At the end of February you can expect higher temperatures, the average highest temperature is around 3.15 ℃ (37.67 ℉). The average number of rainy days in February is 12.5. The average rainfall is 73.5 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 6:53 (hours and minutes), in the middle of the month 8:31 and at the end of the month 10:09.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 Iceland in March is this: The average highest temperature in Iceland in March is 3.4 ℃ (38.12 ℉). The average lowest temperature is -1.8 ℃ (28.76 ℉). At the beginning of March you can expect lower temperatures, the average highest temperature is around 3.15 ℃ (37.67 ℉). At the end of March you can expect higher temperatures, the average highest temperature is around 4.7 ℃ (40.46 ℉). The average number of rainy days in March is 14.5. The average rainfall is 83.4 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 10:09 (hours and minutes), in the middle of the month 11:47 and at the end of the month 13:25.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 Iceland in April is this: The average highest temperature in Iceland in April is 6 ℃ (42.8 ℉). The average lowest temperature is 0.6 ℃ (33.08 ℉). At the beginning of April you can expect lower temperatures, the average highest temperature is around 4.7 ℃ (40.46 ℉). At the end of April you can expect higher temperatures, the average highest temperature is around 7.85 ℃ (46.13 ℉). The average number of rainy days in April is 12.3. The average rainfall is 58.7 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 13:25 (hours and minutes), in the middle of the month 15:04 and at the end of the month 16:43.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 Iceland in May is this: The average highest temperature in Iceland in May is 9.7 ℃ (49.46 ℉). The average lowest temperature is 3.7 ℃ (38.66 ℉). At the beginning of May you can expect lower temperatures, the average highest temperature is around 7.85 ℃ (46.13 ℉). At the end of May you can expect higher temperatures, the average highest temperature is around 10.9 ℃ (51.62 ℉). The average number of rainy days in May is 9.6. The average rainfall is 42.9 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 16:43 (hours and minutes), in the middle of the month 18:23 and at the end of the month 19:55.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 Iceland in June is this: The average highest temperature in Iceland in June is 12.1 ℃ (53.78 ℉). The average lowest temperature is 7 ℃ (44.6 ℉). At the beginning of June you can expect lower temperatures, the average highest temperature is around 10.9 ℃ (51.62 ℉). At the end of June you can expect higher temperatures, the average highest temperature is around 12.85 ℃ (55.13 ℉). The average number of rainy days in June is 10.6. 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 19:55 (hours and minutes), in the middle of the month 20:59 and at the end of the month 20:57.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 Iceland in July is this: The average highest temperature in Iceland in July is 13.6 ℃ (56.48 ℉). The average lowest temperature is 8.6 ℃ (47.48 ℉). At the beginning of July you can expect lower temperatures, the average highest temperature is around 12.85 ℃ (55.13 ℉). At the end of July you can expect lower temperatures, the average highest temperature is around 13.3 ℃ (55.94 ℉). The average number of rainy days in July is 9.9. The average rainfall is 51 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 20:57 (hours and minutes), in the middle of the month 19:50 and at the end of the month 18:17.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 Iceland in August is this: The average highest temperature in Iceland in August is 13 ℃ (55.4 ℉). The average lowest temperature is 8.2 ℃ (46.76 ℉). At the beginning of August you can expect higher temperatures, the average highest temperature is around 13.3 ℃ (55.94 ℉). At the end of August you can expect lower temperatures, the average highest temperature is around 11.7 ℃ (53.06 ℉). The average number of rainy days in August is 11.6. The average rainfall is 60.6 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 18:17 (hours and minutes), in the middle of the month 16:39 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 Iceland in September is this: The average highest temperature in Iceland in September is 10.4 ℃ (50.72 ℉). The average lowest temperature is 5.3 ℃ (41.54 ℉). At the beginning of September you can expect higher temperatures, the average highest temperature is around 11.7 ℃ (53.06 ℉). At the end of September you can expect lower temperatures, the average highest temperature is around 8.7 ℃ (47.66 ℉). The average number of rainy days in September is 12.5. The average rainfall is 67.8 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 15:01 (hours and minutes), in the middle of the month 13:23 and at the end of the month 11:47.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 Iceland in October is this: The average highest temperature in Iceland in October is 7 ℃ (44.6 ℉). The average lowest temperature is 2.4 ℃ (36.32 ℉). At the beginning of October you can expect higher temperatures, the average highest temperature is around 8.7 ℃ (47.66 ℉). At the end of October you can expect lower temperatures, the average highest temperature is around 5.3 ℃ (41.54 ℉). The average number of rainy days in October is 14.7. The average rainfall is 83.7 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 11:47 (hours and minutes), in the middle of the month 10:10 and at the end of the month 8:33.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 Iceland in November is this: The average highest temperature in Iceland in November is 3.6 ℃ (38.48 ℉). The average lowest temperature is -1.1 ℃ (30.02 ℉). At the beginning of November you can expect higher temperatures, the average highest temperature is around 5.3 ℃ (41.54 ℉). At the end of November you can expect lower temperatures, the average highest temperature is around 3 ℃ (37.4 ℉). The average number of rainy days in November is 12.4. The average rainfall is 73.2 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 8:33 (hours and minutes), in the middle of the month 6:56 and at the end of the month 5:27.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 Iceland in December is this: The average highest temperature in Iceland in December is 2.4 ℃ (36.32 ℉). The average lowest temperature is -2.6 ℃ (27.32 ℉). At the beginning of December you can expect higher temperatures, the average highest temperature is around 3 ℃ (37.4 ℉). At the end of December you can expect lower temperatures, the average highest temperature is around 2.25 ℃ (36.05 ℉). The average number of rainy days in December is 14.2. The average rainfall is 78.3 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 5:27 (hours and minutes), in the middle of the month 4:22 and at the end of the month 4:10.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.| Stykkisholmur | temperature: -0.2 ℃ (31.64 ℉) | highest temperature: 2.3 ℃ (36.14 ℉) | lowest temperature: -2.4 ℃ (27.68 ℉) | rainfall: 70.5mm | rainy days: - |
| Vestmannaeyjar | temperature: 2 ℃ (35.6 ℉) | highest temperature: 4.2 ℃ (39.56 ℉) | lowest temperature: 0 ℃ (32 ℉) | rainfall: 144.9mm | rainy days: - |
| Akureyri | temperature: -1.3 ℃ (29.66 ℉) | highest temperature: 1.9 ℃ (35.42 ℉) | lowest temperature: -4.4 ℃ (24.08 ℉) | rainfall: 51.7mm | rainy days: - |
| Kirkjubaejarklaustur | temperature: 0.2 ℃ (32.36 ℉) | highest temperature: 2.7 ℃ (36.86 ℉) | lowest temperature: -2.5 ℃ (27.5 ℉) | rainfall: 131.6mm | rainy days: - |
| Raufarhofn | temperature: -1.4 ℃ (29.48 ℉) | highest temperature: 1.4 ℃ (34.52 ℉) | lowest temperature: -4.2 ℃ (24.44 ℉) | rainfall: 75.8mm | rainy days: - |
| Dalatangi | temperature: 1.2 ℃ (34.16 ℉) | highest temperature: 3.9 ℃ (39.02 ℉) | lowest temperature: -1.2 ℃ (29.84 ℉) | rainfall: 119mm | rainy days: - |