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.

• Sunday
  7th Sep
  28
  27
  
  5
  11
• Monday
  8th Sep
  28
  28
  
  5
  11
• Tuesday
  9th Sep
  28
  28
  
  7
  11
• Wednesday
  10th Sep
  28
  28
  
  8
  11
• Thursday
  11th Sep
  28
  28
  
  7
  11

5-day weather forecast updated at 04:01 on Sunday 7th September 2025 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 Sunday 7th September 2025

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 86% chance of some rain and a gentle breeze of 18 kph from the east.

• 28
  °C maximum temperature
• 27
  °C minimum temperature
• 
  isolated thunderstorms
• 5
  hours of sunshine
• 11
  UV index (Extreme)
• 86
  % chance of some rain
• <10
  mm of rainfall expected
• L
  low heat & humidity
• 18
  kph wind from E

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Union Island weather for Monday 8th September 2025

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 49% chance of some rain and a gentle breeze of 18 kph from the east.

• 28
  °C maximum temperature
• 28
  °C minimum temperature
• 
  isolated thunderstorms
• 5
  hours of sunshine
• 11
  UV index (Extreme)
• 49
  % chance of some rain
• <10
  mm of rainfall expected
• L
  low heat & humidity
• 18
  kph wind from E

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Union Island weather for Tuesday 9th September 2025

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 7 hours of bright sunshine. There are 2-5 mm of rainfall expected with 48% chance of some rain and a gentle breeze of 19 kph from the east.

• 28
  °C maximum temperature
• 28
  °C minimum temperature
• 
  isolated thunderstorms
• 7
  hours of sunshine
• 11
  UV index (Extreme)
• 48
  % chance of some rain
• <5
  mm of rainfall expected
• M
  moderate heat & humidity
• 19
  kph wind from E

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Union Island weather for Wednesday 10th September 2025

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 8 hours of bright sunshine. There are 5-10 mm of rainfall expected with 64% chance of some rain and a gentle breeze of 19 kph from the east.

• 28
  °C maximum temperature
• 28
  °C minimum temperature
• 
  isolated thunderstorms
• 8
  hours of sunshine
• 11
  UV index (Extreme)
• 64
  % chance of some rain
• <10
  mm of rainfall expected
• M
  moderate heat & humidity
• 19
  kph wind from E

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Union Island weather for Thursday 11th September 2025

Expect broken clouds 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 7 hours of bright sunshine. There are 0 mm of rainfall expected and a moderate breeze of 20 kph from the east.

• 28
  °C maximum temperature
• 28
  °C minimum temperature
• 
  broken clouds
• 7
  hours of sunshine
• 11
  UV index (Extreme)
• 0
  mm of rainfall expected
• L
  low heat & humidity
• 20
  kph wind from E

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Sandals sale: up to £300 off Caribbean holidays

Discount Code

• Save up to £300 on all inclusive holidays to the Caribbean
• Discount varies by total spend. 7 night minimum stay
• Travel before 31st December 2027 (inclusive)

Show discount code ******ALE

Redeem Sandals discount code >>

Expires at 23:59 on Tuesday 30th Sep 2025 · View all Sandals offers

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

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