Union Island weather live forecast

Today's maximum temperature in Union Island is expected to be 28°C. Select a day from the live weather forecast for Union Island, St Vincent & the Grenadines for more weather parameters.

Thursday
13th Aug
28

27

6

11
Friday
14th Aug
28

28

6

10
Saturday
15th Aug
28

27

4

10
Sunday
16th Aug
28

27

5

11
Monday
17th Aug
28

28

5

11

5-day weather forecast updated at 04:01 on Thursday 13th August 2026 GMT

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

Sale

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

Cruise deal finder

Destination

The 5-day weather forecast for St Vincent & the Grenadines (Union Island) is provided by the Swiss meteorological agency, meteoblue. Find out more about our data sources.

Union Island weather forecast by day

Below are the detailed weather forecasts for Union Island for the next 5 days.

Union Island weather for Thursday 13th August 2026

Expect isolated thunderstorms in Union Island, St Vincent & the Grenadines with a maximum temperature of 28°C, moderate levels of heat & humidity, maximum UV of 11 (Extreme) and 6 hours of bright sunshine. There are 0-2 mm of rainfall expected with 20% chance of some rain and a fresh breeze of 31 kph from the east.

28
°C maximum temperature
27
°C minimum temperature
isolated thunderstorms
6
hours of sunshine
11
UV index (Extreme)
20
% chance of some rain
<2
mm of rainfall expected
M
moderate heat & humidity
31
kph wind from E

Union Island weather for Friday 14th August 2026

Expect broken clouds in Union Island, St Vincent & the Grenadines with a maximum temperature of 28°C, moderate levels of heat & humidity, maximum UV of 10 (Very High) and 6 hours of bright sunshine. There are 0 mm of rainfall expected and a fresh breeze of 36 kph from the east.

28
°C maximum temperature
28
°C minimum temperature
broken clouds
6
hours of sunshine
10
UV index (Very High)
0
mm of rainfall expected
M
moderate heat & humidity
36
kph wind from E

Union Island weather for Saturday 15th August 2026

Expect isolated thunderstorms in Union Island, St Vincent & the Grenadines with a maximum temperature of 28°C, low levels of heat & humidity, maximum UV of 10 (Very High) and 4 hours of bright sunshine. There are 10-20 mm of rainfall expected with 68% chance of some rain and a fresh breeze of 30 kph from the east.

28
°C maximum temperature
27
°C minimum temperature
isolated thunderstorms
4
hours of sunshine
10
UV index (Very High)
68
% chance of some rain
<20
mm of rainfall expected
L
low heat & humidity
30
kph wind from E

Union Island weather for Sunday 16th August 2026

Expect isolated thunderstorms in Union Island, St Vincent & the Grenadines with a maximum temperature of 28°C, moderate levels of heat & humidity, maximum UV of 11 (Extreme) and 5 hours of bright sunshine. There are 10-20 mm of rainfall expected with 75% chance of some rain and a moderate breeze of 24 kph from the east.

28
°C maximum temperature
27
°C minimum temperature
isolated thunderstorms
5
hours of sunshine
11
UV index (Extreme)
75
% chance of some rain
<20
mm of rainfall expected
M
moderate heat & humidity
24
kph wind from E

Union Island weather for Monday 17th August 2026

Expect isolated thunderstorms in Union Island, St Vincent & the Grenadines with a maximum temperature of 28°C, low levels of heat & humidity, maximum UV of 11 (Extreme) and 5 hours of bright sunshine. There are 10-20 mm of rainfall expected with 62% chance of some rain and a moderate breeze of 23 kph from the east.