Climate and monthly weather forecastTanna, Vanuatu

The climate of Tanna

Tanna, an island in Vanuatu, is characterised by a Köppen climate classification of Af, pointing to a tropical rainforest layout. Located in the South Pacific Ocean, the island witnesses climate conditions reflective of its geographical positioning, experiencing high rainfall almost uniformly throughout the year.

Temperature variation over the year is gradual and minimal, with the highest average temperature being 29°C (84.2°F) in February and the lowest at about 24°C (75.2°F) from July to September. Consequently, Tanna experiences a tropical climate, epitomised by warm temperatures throughout the year. Contrastingly, rainfall oscillates from a peak of 355mm (13.98") in March to lows of 109mm (4.29") in October, showing a more significant shrift between wet and dry periods.

Predominantly a sunlit island, Tanna receives between 11 to 13.3 hours of daylight throughout the year, with the longest day occurring in December. Sunshine hours remain stable with an average of 6 to 7 hours daily. Solar radiation reflected in the UV index, commensurate with the highest possible value of 12 from January to March and in November and December, signalling a high risk of harm from unprotected sun exposure.

The best time to visit Tanna

Factoring weather parameters such as temperature, rainfall, humidity it can be pinpointed that the ideal time to visit Tanna would be between June to September. During this period, the island experiences the most favourable combination of weather conditions. The tropical heat is at its gentlest, averaging 24°C (75.2°F) to 25°C (77°F), and rainfall is minimal, ranging from 128mm (5.04") to 178mm (7.01"), making it the most accommodating season for outdoor activities and beach visits. Additionally, the UV index falls to manageable levels of 7 and 9, thus reducing the risk associated with sun exposure.

The worst time to visit Tanna

Conversely, the period between January to March may prove to be rather challenging for a visit to Tanna. This time constitutes the wettest period with rainfall peaking at 355mm (13.98") in March, potentially causing disruptions to travel plans. Coupled with intense solar radiation marked by a UV index of 12, the weather conditions during this period are considerably harsh and could result in discomfort for travellers.

Spring weather in Tanna

In Tanna, spring weather from September to November brings with it increased sunshine hours and slightly warmer temperatures. Temperature levels ascend gradually from 24°C (75.2°F) in September to 26°C (78.8°F) in November, marking a subtle transition from colder to warmer months. Rainfall starts to rise from a low of 125mm (4.92") in September to a noticeable 185mm (7.28") by November, signifying the onset of a wetter season. Despite increased rainfall, the amount of sunshine remains consistent at 7 hours per day, providing ample daylight for activities.

Summer weather in Tanna

From December to February, Tanna experiences its summer season. Characterised by peak temperatures, heavy rainfall and intense solar radiation, this period culminates in the hottest month of the year in February, with temperatures averaging 29°C (84.2°F). Rainfall also amplifies during this period, touching 334mm (13.15") in December and 266mm (10.47") in February. Interestingly, despite the increase in rainfall, this period does not witness any substantial dip in sunshine hours, sustaining a stable 7 hours daily.

Autumn weather in Tanna

As Tanna transitions into autumn from March to May, there is a noticeable decrease in temperature and increased precipitation. Average high temperatures drop from 28°C (82.4°F) in March to 25°C (77°F) in May, indicating a cooling trend. Rainfall is pronounced in March with 355mm (13.98") but diminishes to 181mm (7.13") by the end of May. Importantly, the island continues to receive 6 hours of sunshine daily, with the UV index now dropping to a lower, yet still high, 8 in May.

Winter weather in Tanna

Winter in Tanna, occurring from June to August, is characterised by the coolest but also the driest period of the year. The mean highest temperature drops to its lowest point, maintaining a constant 24°C (75.2°F) over these three months. Rainfall also reduces significantly to around 128mm (5.04") in June and 178mm (7.01") in August. Concurrently, sunshine hours remain constant at an average of 6 hours per day even as daylight hours slightly recede to 11.1 hours in June before gradually increasing to 11.5 hours in August. Hence, winter on this tropical island retains its warm character; however, mellowed by a lower intensity of rainfall and UV index.

Weather in January

The New Year begins with rather hot and wet conditions in Tanna, Vanuatu. The daily readings fluctuate between highs of 28°C (82.4°F) and lows of 21°C (69.8°F), making it a moderately comfortable time for venturing outdoors. Weather in January »

Weather in February

The weather in February continues much of the trends observed in January. Sea temperatures remain high, promoting various water-related activities. Though the rainfall lessens to 266mm (10.47") from the previous month, conditions are still substantially damp. Weather in February »

Weather in March

Heading into March, weather shifts toward a wetter climate, making it the rainiest month with 355mm (13.98") of rainfall. albeit, the average number of rainy days does not drastically increase. The high UV index, unchanged from the previous months, continues to call for sun-protective measures. Weather in March »

Weather in April

April weather marks a transition from the earlier hot, humid conditions of the year. Rainfall substantially reduces to 210mm (8.27"), bringing a slight respite from the prior wetter conditions. Significantly, daily temperatures start to dip, heralding the onset of mildly cooler nights ahead. Weather in April »

Weather in May

May presents a further reduction of precipitation, down to 181mm (7.13"), nudging the weather towards drier conditions. The decline in the daily temperature range continues, with the lowest high temperature recording of 25°C (77°F) for the first half of the year. Weather in May »

Weather in June

The weather in June on the Vanuatu island of Tanna continues the cooling trend. The daily lows dips down to 17°C (62.6°F) offering more comfortable nights despite the high level of humidity. Rainfall reduces slightly further to 164mm (6.46"), keeping the environment lush. Weather in June »

Weather in July

July is the year's coolest month, with daily temperatures near 24°C (75.2°F), and at the lowest of 16°C (60.8°F). Rainfall gets notably subdued, down to 128mm (5.04"), marking the driest phase of the year. Sea temperatures hit yearly low, yet remain favorable for water-based activities. Weather in July »

Weather in August

August weather remains predominantly cool; however, the rainfall increases compared to July, reaching 178mm (7.01"). The daily lows hover around the optimum 16°C (60.8°F) mark, ensuring comfortable nights. The month also enjoys marginally extended daylight hours. Weather in August »

Weather in September

The arrival of September brings subtly warmer days in Tanna, while the rainfall decreases to 125mm (4.92"). This decline in rainfall characterizes the drying trend of the Vanuatu's weather. In line with the season shift, daylight extends into longer periods. Weather in September »

Weather in October

October witnesses a slight increase in both daily high and low temperatures. Rainfall continues its descent to 109mm (4.29") making it the least rainy month of the year. The sea temperature, consistent with seasonal variations, begins to climb upwards. Weather in October »

Weather in November

November marks a shift towards the wet season, with rainfall increasing to 185mm (7.28"). The mercury scale records a slight uptick, suggesting a warm-up trend in the island's weather. Albeit with reduced daylight hours, sunshine availability remains sufficient. Weather in November »

Weather in December

December registers a slightly increasing trend in temperatures, signaling the onset of warmer days. The winter rainfall concludes the annual circle by recording 200mm (7.87"), close to the year's average. Sea temperatures are inviting, reaching up to 27°C (80.6°F) just in time for holiday season swims. Weather in December »