Union Island weather by month

Check out Union Island weather averages by month. Compare detailed monthly climate statistics including temperature, rainfall and sunshine figures.

Temperature in Union Island (°C)

  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Max temperature (daytime)
29°C maximum daytime temperature in January in Union Island29
29°C maximum daytime temperature in February in Union Island29
29°C maximum daytime temperature in March in Union Island29
30°C maximum daytime temperature in April in Union Island30
30°C maximum daytime temperature in May in Union Island30
30°C maximum daytime temperature in June in Union Island30
30°C maximum daytime temperature in July in Union Island30
30°C maximum daytime temperature in August in Union Island30
30°C maximum daytime temperature in September in Union Island30
30°C maximum daytime temperature in October in Union Island30
30°C maximum daytime temperature in November in Union Island30
29°C maximum daytime temperature in December in Union Island29
Min temperature (night-time)
21°C minimum night-time temperature in January in Union Island21
21°C minimum night-time temperature in February in Union Island21
21°C minimum night-time temperature in March in Union Island21
22°C minimum night-time temperature in April in Union Island22
23°C minimum night-time temperature in May in Union Island23
23°C minimum night-time temperature in June in Union Island23
23°C minimum night-time temperature in July in Union Island23
23°C minimum night-time temperature in August in Union Island23
23°C minimum night-time temperature in September in Union Island23
23°C minimum night-time temperature in October in Union Island23
22°C minimum night-time temperature in November in Union Island22
21°C minimum night-time temperature in December in Union Island21
Heat & Humidity
High heat & humidity in January in Union IslandH
High heat & humidity in February in Union IslandH
High heat & humidity in March in Union IslandH
High heat & humidity in April in Union IslandH
High heat & humidity in May in Union IslandH
High heat & humidity in June in Union IslandH
High heat & humidity in July in Union IslandH
Very high heat & humidity in August in Union IslandVH
Very high heat & humidity in September in Union IslandVH
Very high heat & humidity in October in Union IslandVH
High heat & humidity in November in Union IslandH
High heat & humidity in December in Union IslandH
Sea temperature
27°C sea temperature in January in Union Island27
26°C sea temperature in February in Union Island26
27°C sea temperature in March in Union Island27
27°C sea temperature in April in Union Island27
27°C sea temperature in May in Union Island27
27°C sea temperature in June in Union Island27
28°C sea temperature in July in Union Island28
28°C sea temperature in August in Union Island28
29°C sea temperature in September in Union Island29
29°C sea temperature in October in Union Island29
28°C sea temperature in November in Union Island28
28°C sea temperature in December in Union Island28

Note: 0 = None, L = Low, M = Moderate, H = High, VH = Very high, E = Extreme

Sunshine & UV index in Union Island

  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Daily hours of sunshine
Daily hours of daylight
11 hours of daylight per day in January in Union Island11
12 hours of daylight per day in February in Union Island12
12 hours of daylight per day in March in Union Island12
12 hours of daylight per day in April in Union Island12
13 hours of daylight per day in May in Union Island13
13 hours of daylight per day in June in Union Island13
13 hours of daylight per day in July in Union Island13
13 hours of daylight per day in August in Union Island13
12 hours of daylight per day in September in Union Island12
12 hours of daylight per day in October in Union Island12
12 hours of daylight per day in November in Union Island12
11 hours of daylight per day in December in Union Island11
UV Index (Maximum)
UV (maximum) index 10 (Very High) in January in Union Island10
UV (maximum) index 11+ (Extreme) in February in Union Island11
UV (maximum) index 11+ (Extreme) in March in Union Island11
UV (maximum) index 11+ (Extreme) in April in Union Island11
UV (maximum) index 11+ (Extreme) in May in Union Island11
UV (maximum) index 11+ (Extreme) in June in Union Island11
UV (maximum) index 11+ (Extreme) in July in Union Island11
UV (maximum) index 11+ (Extreme) in August in Union Island11
UV (maximum) index 11+ (Extreme) in September in Union Island11
UV (maximum) index 11 (Extreme) in October in Union Island11
UV (maximum) index 10 (Very High) in November in Union Island10
UV (maximum) index 9 (Very High) in December in Union Island9

Rainfall in Union Island

  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Number of days with some rain
16 days with some rainfall in January in Union Island16
12 days with some rainfall in February in Union Island12
12 days with some rainfall in March in Union Island12
10 days with some rainfall in April in Union Island10
14 days with some rainfall in May in Union Island14
18 days with some rainfall in June in Union Island18
21 days with some rainfall in July in Union Island21
20 days with some rainfall in August in Union Island20
21 days with some rainfall in September in Union Island21
18 days with some rainfall in October in Union Island18
20 days with some rainfall in November in Union Island20
18 days with some rainfall in December in Union Island18
Average monthly rainfall (mm)
78 mm monthly rainfall in January in Union Island78
57 mm monthly rainfall in February in Union Island57
59 mm monthly rainfall in March in Union Island59
58 mm monthly rainfall in April in Union Island58
76 mm monthly rainfall in May in Union Island76
155 mm monthly rainfall in June in Union Island155
203 mm monthly rainfall in July in Union Island203
195 mm monthly rainfall in August in Union Island195
186 mm monthly rainfall in September in Union Island186
207 mm monthly rainfall in October in Union Island207
182 mm monthly rainfall in November in Union Island182
138 mm monthly rainfall in December in Union Island138

More about Union Island

Union Island by month

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Recommended for St Vincent & the Grenadines

Marella Cruises: Best deals on summer sailings

  • Check out best deals on all-inclusive summer sailings
  • Book cruises to the Med including 30th Birthday sailings
  • Filter deals by departure port, party size & duration
Go to Marella Cruises deal >>

View all Marella Cruises offers

Marella CruisesCruise deal finder

The climate guide for St Vincent & the Grenadines (Union Island) shows long term monthly weather averages processed from data supplied by CRU (University of East Anglia), the Met Office & the Netherlands Meteorological Institute. Find out more about our data sources.

What's the climate like in Union Island?

Union Island has a hot tropical climate with no dry season.

Union Island weather in January

Expect daytime maximum temperatures of 29°C in Union Island, St Vincent & the Grenadines in January and high heat and humidity based on long-term weather averages. There are 8 hours of sunshine per day on average with 16 days with some rainfall and typically 78 mm of rainfall in the month.

  • 29°C maximum daytime temperature in January in Union Island29
    29°C max day temperature
  • 8 hours of sunshine per day
  • 16 days with some rainfall in January in Union Island16
    16 days with some rainfall
  • 21°C minimum night-time temperature in January in Union Island21
    21°C min night temperature
  • 11 hours of daylight per day in January in Union Island11
    11 hours of daylight per day
  • High heat & humidity in January in Union IslandH
    High heat & humidity
  • 78 mm monthly rainfall in January in Union Island78
    78 mm of monthly rainfall
  • UV (maximum) index 10 (Very High) in January in Union Island10
    10 (Very High) UV index
  • 27°C sea temperature in January in Union Island27
    27°C sea temperature

Back to months

Union Island weather in February

Expect daytime maximum temperatures of 29°C in Union Island, St Vincent & the Grenadines in February and high heat and humidity based on long-term weather averages. There are 8 hours of sunshine per day on average with 12 days with some rainfall and typically 57 mm of rainfall in the month.

  • 29°C maximum daytime temperature in February in Union Island29
    29°C max day temperature
  • 8 hours of sunshine per day
  • 12 days with some rainfall in February in Union Island12
    12 days with some rainfall
  • 21°C minimum night-time temperature in February in Union Island21
    21°C min night temperature
  • 12 hours of daylight per day in February in Union Island12
    12 hours of daylight per day
  • High heat & humidity in February in Union IslandH
    High heat & humidity
  • 57 mm monthly rainfall in February in Union Island57
    57 mm of monthly rainfall
  • UV (maximum) index 11+ (Extreme) in February in Union Island11
    11+ (Extreme) UV index
  • 26°C sea temperature in February in Union Island26
    26°C sea temperature

Back to months

Union Island weather in March

Expect daytime maximum temperatures of 29°C in Union Island, St Vincent & the Grenadines in March and high heat and humidity based on long-term weather averages. There are 8 hours of sunshine per day on average with 12 days with some rainfall and typically 59 mm of rainfall in the month.

  • 29°C maximum daytime temperature in March in Union Island29
    29°C max day temperature
  • 8 hours of sunshine per day
  • 12 days with some rainfall in March in Union Island12
    12 days with some rainfall
  • 21°C minimum night-time temperature in March in Union Island21
    21°C min night temperature
  • 12 hours of daylight per day in March in Union Island12
    12 hours of daylight per day
  • High heat & humidity in March in Union IslandH
    High heat & humidity
  • 59 mm monthly rainfall in March in Union Island59
    59 mm of monthly rainfall
  • UV (maximum) index 11+ (Extreme) in March in Union Island11
    11+ (Extreme) UV index
  • 27°C sea temperature in March in Union Island27
    27°C sea temperature

Back to months

Union Island weather in April

Expect daytime maximum temperatures of 30°C in Union Island, St Vincent & the Grenadines in April and high heat and humidity based on long-term weather averages. There are 8 hours of sunshine per day on average with 10 days with some rainfall and typically 58 mm of rainfall in the month.

  • 30°C maximum daytime temperature in April in Union Island30
    30°C max day temperature
  • 8 hours of sunshine per day
  • 10 days with some rainfall in April in Union Island10
    10 days with some rainfall
  • 22°C minimum night-time temperature in April in Union Island22
    22°C min night temperature
  • 12 hours of daylight per day in April in Union Island12
    12 hours of daylight per day
  • High heat & humidity in April in Union IslandH
    High heat & humidity
  • 58 mm monthly rainfall in April in Union Island58
    58 mm of monthly rainfall
  • UV (maximum) index 11+ (Extreme) in April in Union Island11
    11+ (Extreme) UV index
  • 27°C sea temperature in April in Union Island27
    27°C sea temperature

Back to months

Union Island weather in May

Expect daytime maximum temperatures of 30°C in Union Island, St Vincent & the Grenadines in May and high heat and humidity based on long-term weather averages. There are 8 hours of sunshine per day on average with 14 days with some rainfall and typically 76 mm of rainfall in the month.

  • 30°C maximum daytime temperature in May in Union Island30
    30°C max day temperature
  • 8 hours of sunshine per day
  • 14 days with some rainfall in May in Union Island14
    14 days with some rainfall
  • 23°C minimum night-time temperature in May in Union Island23
    23°C min night temperature
  • 13 hours of daylight per day in May in Union Island13
    13 hours of daylight per day
  • High heat & humidity in May in Union IslandH
    High heat & humidity
  • 76 mm monthly rainfall in May in Union Island76
    76 mm of monthly rainfall
  • UV (maximum) index 11+ (Extreme) in May in Union Island11
    11+ (Extreme) UV index
  • 27°C sea temperature in May in Union Island27
    27°C sea temperature

Back to months

Union Island weather in June

Expect daytime maximum temperatures of 30°C in Union Island, St Vincent & the Grenadines in June and high heat and humidity based on long-term weather averages. There are 7 hours of sunshine per day on average with 18 days with some rainfall and typically 155 mm of rainfall in the month.

  • 30°C maximum daytime temperature in June in Union Island30
    30°C max day temperature
  • 7 hours of sunshine per day
  • 18 days with some rainfall in June in Union Island18
    18 days with some rainfall
  • 23°C minimum night-time temperature in June in Union Island23
    23°C min night temperature
  • 13 hours of daylight per day in June in Union Island13
    13 hours of daylight per day
  • High heat & humidity in June in Union IslandH
    High heat & humidity
  • 155 mm monthly rainfall in June in Union Island155
    155 mm of monthly rainfall
  • UV (maximum) index 11+ (Extreme) in June in Union Island11
    11+ (Extreme) UV index
  • 27°C sea temperature in June in Union Island27
    27°C sea temperature

Back to months

Union Island weather in July

Expect daytime maximum temperatures of 30°C in Union Island, St Vincent & the Grenadines in July and high heat and humidity based on long-term weather averages. There are 7 hours of sunshine per day on average with 21 days with some rainfall and typically 203 mm of rainfall in the month.

  • 30°C maximum daytime temperature in July in Union Island30
    30°C max day temperature
  • 7 hours of sunshine per day
  • 21 days with some rainfall in July in Union Island21
    21 days with some rainfall
  • 23°C minimum night-time temperature in July in Union Island23
    23°C min night temperature
  • 13 hours of daylight per day in July in Union Island13
    13 hours of daylight per day
  • High heat & humidity in July in Union IslandH
    High heat & humidity
  • 203 mm monthly rainfall in July in Union Island203
    203 mm of monthly rainfall
  • UV (maximum) index 11+ (Extreme) in July in Union Island11
    11+ (Extreme) UV index
  • 28°C sea temperature in July in Union Island28
    28°C sea temperature

Back to months

Union Island weather in August

Expect daytime maximum temperatures of 30°C in Union Island, St Vincent & the Grenadines in August and very high heat and humidity based on long-term weather averages. There are 8 hours of sunshine per day on average with 20 days with some rainfall and typically 195 mm of rainfall in the month.

  • 30°C maximum daytime temperature in August in Union Island30
    30°C max day temperature
  • 8 hours of sunshine per day
  • 20 days with some rainfall in August in Union Island20
    20 days with some rainfall
  • 23°C minimum night-time temperature in August in Union Island23
    23°C min night temperature
  • 13 hours of daylight per day in August in Union Island13
    13 hours of daylight per day
  • Very high heat & humidity in August in Union IslandVH
    Very High heat & humidity
  • 195 mm monthly rainfall in August in Union Island195
    195 mm of monthly rainfall
  • UV (maximum) index 11+ (Extreme) in August in Union Island11
    11+ (Extreme) UV index
  • 28°C sea temperature in August in Union Island28
    28°C sea temperature

Back to months

Union Island weather in September

Expect daytime maximum temperatures of 30°C in Union Island, St Vincent & the Grenadines in September and very high heat and humidity based on long-term weather averages. There are 7 hours of sunshine per day on average with 21 days with some rainfall and typically 186 mm of rainfall in the month.

  • 30°C maximum daytime temperature in September in Union Island30
    30°C max day temperature
  • 7 hours of sunshine per day
  • 21 days with some rainfall in September in Union Island21
    21 days with some rainfall
  • 23°C minimum night-time temperature in September in Union Island23
    23°C min night temperature
  • 12 hours of daylight per day in September in Union Island12
    12 hours of daylight per day
  • Very high heat & humidity in September in Union IslandVH
    Very High heat & humidity
  • 186 mm monthly rainfall in September in Union Island186
    186 mm of monthly rainfall
  • UV (maximum) index 11+ (Extreme) in September in Union Island11
    11+ (Extreme) UV index
  • 29°C sea temperature in September in Union Island29
    29°C sea temperature

Back to months

Union Island weather in October

Expect daytime maximum temperatures of 30°C in Union Island, St Vincent & the Grenadines in October and very high heat and humidity based on long-term weather averages. There are 7 hours of sunshine per day on average with 18 days with some rainfall and typically 207 mm of rainfall in the month.

  • 30°C maximum daytime temperature in October in Union Island30
    30°C max day temperature
  • 7 hours of sunshine per day
  • 18 days with some rainfall in October in Union Island18
    18 days with some rainfall
  • 23°C minimum night-time temperature in October in Union Island23
    23°C min night temperature
  • 12 hours of daylight per day in October in Union Island12
    12 hours of daylight per day
  • Very high heat & humidity in October in Union IslandVH
    Very High heat & humidity
  • 207 mm monthly rainfall in October in Union Island207
    207 mm of monthly rainfall
  • UV (maximum) index 11 (Extreme) in October in Union Island11
    11 (Extreme) UV index
  • 29°C sea temperature in October in Union Island29
    29°C sea temperature

Back to months

Union Island weather in November

Expect daytime maximum temperatures of 30°C in Union Island, St Vincent & the Grenadines in November and high heat and humidity based on long-term weather averages. There are 7 hours of sunshine per day on average with 20 days with some rainfall and typically 182 mm of rainfall in the month.

  • 30°C maximum daytime temperature in November in Union Island30
    30°C max day temperature
  • 7 hours of sunshine per day
  • 20 days with some rainfall in November in Union Island20
    20 days with some rainfall
  • 22°C minimum night-time temperature in November in Union Island22
    22°C min night temperature
  • 12 hours of daylight per day in November in Union Island12
    12 hours of daylight per day
  • High heat & humidity in November in Union IslandH
    High heat & humidity
  • 182 mm monthly rainfall in November in Union Island182
    182 mm of monthly rainfall
  • UV (maximum) index 10 (Very High) in November in Union Island10
    10 (Very High) UV index
  • 28°C sea temperature in November in Union Island28
    28°C sea temperature

Back to months

Union Island weather in December

Expect daytime maximum temperatures of 29°C in Union Island, St Vincent & the Grenadines in December and high heat and humidity based on long-term weather averages. There are 7 hours of sunshine per day on average with 18 days with some rainfall and typically 138 mm of rainfall in the month.

  • 29°C maximum daytime temperature in December in Union Island29
    29°C max day temperature
  • 7 hours of sunshine per day
  • 18 days with some rainfall in December in Union Island18
    18 days with some rainfall
  • 21°C minimum night-time temperature in December in Union Island21
    21°C min night temperature
  • 11 hours of daylight per day in December in Union Island11
    11 hours of daylight per day
  • High heat & humidity in December in Union IslandH
    High heat & humidity
  • 138 mm monthly rainfall in December in Union Island138
    138 mm of monthly rainfall
  • UV (maximum) index 9 (Very High) in December in Union Island9
    9 (Very High) UV index
  • 28°C sea temperature in December in Union Island28
    28°C sea temperature

Back to months

More about Union Island

Union Island by month

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Recommended for St Vincent & the Grenadines

Marella Cruises: Best deals on summer sailings

  • Check out best deals on all-inclusive summer sailings
  • Book cruises to the Med including 30th Birthday sailings
  • Filter deals by departure port, party size & duration
Go to Marella Cruises deal >>

View all Marella Cruises offers

Marella CruisesCruise deal finder

The climate guide for St Vincent & the Grenadines (Union Island) shows long term monthly weather averages processed from data supplied by CRU (University of East Anglia), the Met Office & the Netherlands Meteorological Institute. Find out more about our data sources.

Compare Union Island weather with the UK

The weather chart below compares the average monthly maximum daytime temperature for Union Island, St Vincent and the Grenadines and the UK (London).

Maximum daytime temperature (°C)

Union Island, St Vincent and the Grenadines
UK (London)
29
7
29
7
29
10
30
13
30
17
30
20
30
22
30
22
30
19
30
15
30
10
29
8
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Metric (°C / mm)  |  Imperial (°F / inches)

Compare more weather >>

Back to top

More about St Vincent & the Grenadines

Related posts

Popular travel offers

Explore holiday destinations

More holidays

Save with latest deals & discounts

More deals

Airport parking

More parking

Airport lounges

More lounges

Top ^