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
20th Aug
28

27

5

9
Friday
21st Aug
27

27

4

9
Saturday
22nd Aug
28

27

5

11
Sunday
23rd Aug
28

28

6

8
Monday
24th Aug
28

27

6

11

5-day weather forecast updated at 04:01 on Wednesday 19th August 2026 GMT

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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 20th 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 9 (Very High) and 5 hours of bright sunshine. There are 10-20 mm of rainfall expected with 72% chance of some rain and a moderate breeze of 27 kph from the east.

28
°C maximum temperature
27
°C minimum temperature
isolated thunderstorms
5
hours of sunshine
9
UV index (Very High)
72
% chance of some rain
<20
mm of rainfall expected
L
low heat & humidity
27
kph wind from E

Union Island weather for Friday 21st August 2026

Expect isolated thunderstorms in Union Island, St Vincent & the Grenadines with a maximum temperature of 27°C, low levels of heat & humidity, maximum UV of 9 (Very High) and 4 hours of bright sunshine. There are 0-2 mm of rainfall expected with 64% chance of some rain and a moderate breeze of 25 kph from the east.

27
°C maximum temperature
27
°C minimum temperature
isolated thunderstorms
4
hours of sunshine
9
UV index (Very High)
64
% chance of some rain
<2
mm of rainfall expected
L
low heat & humidity
25
kph wind from E

Union Island weather for Saturday 22nd 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 5-10 mm of rainfall expected with 64% chance of some rain and a moderate breeze of 22 kph from the east.

28
°C maximum temperature
27
°C minimum temperature
isolated thunderstorms
5
hours of sunshine
11
UV index (Extreme)
64
% chance of some rain
<10
mm of rainfall expected
L
low heat & humidity
22
kph wind from E

Union Island weather for Sunday 23rd 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 8 (Very High) and 6 hours of bright sunshine. There are 10-20 mm of rainfall expected with 69% chance of some rain and a moderate breeze of 21 kph from the east.

28
°C maximum temperature
28
°C minimum temperature
isolated thunderstorms
6
hours of sunshine
8
UV index (Very High)
69
% chance of some rain
<20
mm of rainfall expected
L
low heat & humidity
21
kph wind from E

Union Island weather for Monday 24th 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 6 hours of bright sunshine. There are 2-5 mm of rainfall expected with 67% chance of some rain and a gentle breeze of 19 kph from the east.