Weather forecast for 10 daysUmatac, GU

Weather forecast for the weekend

Sunday Oct 18, 2026

  • 81°F
  • 79°F
Heavy Rain / Wind
Heavy Rain / Wind
  • Precip. probability: 100%
  • Precipitation: 4.8"
  • Wind: 78mphSE 142°
  • Humidity: 94%
  • UV index: 4
  • Sunrise: 6:12 am ChST
  • Sunset: 6:00 pm ChST
  • ▼
Tomorrow, on Sunday, persistent rain and gusty winds are forecasted, leading to saturated ground conditions.
Extreme precipitation of 4.8" is predicted. A slight fluctuation in temperature is expected, achieving a maximum of a temperate 80.6°F and dipping to a minimum of a warm 78.8°F.
The maximum heat index, which adjusts the air temperature based on humidity, is calculated to be a blazing 87.8°F. Take into consideration that the heat index values are calculated for shade and light wind conditions.
Forecasts suggest the maximum temperature will be moderately lower than October's average of 84.4°F.
Sunrise will be at 6:12 am and sunset at 6:00 pm; tomorrow's daylight will last for 11h and 49min.

10-day overview

Daily temperatures

Warmest period: Tuesday - Monday 84°C.
Coldest day: tomorrow 81°C.

Chance of precipitation

Highest chance: today - tomorrow 100%.

Long-term weather forecast

  • Saturday
  • Oct 17, 2026
  • min.
  • 79°F
Rain / Wind
Rain / Wind
  • Precip. probability: 100%
  • Precipitation: 1.5"
  • Wind: 90mphNNE 33°
  • Humidity: 95%
  • UV index: 0
  • Sunrise: 6:12 am ChST
  • Sunset: 6:01 pm ChST
  • ▼
  • Sunday
  • Oct 18, 2026
  • 81°F
  • 79°F
Heavy Rain / Wind
Heavy Rain / Wind
  • Precip. probability: 100%
  • Precipitation: 4.8"
  • Wind: 78mphSE 142°
  • Humidity: 94%
  • UV index: 4
  • Sunrise: 6:12 am ChST
  • Sunset: 6:00 pm ChST
  • ▼
  • Monday
  • Oct 19, 2026
  • 82°F
  • 79°F
Showers / Wind
Showers / Wind
  • Precip. probability: 73%
  • Precipitation: 0.55"
  • Wind: 24mphSSE 151°
  • Humidity: 88%
  • UV index: 6
  • Sunrise: 6:12 am ChST
  • Sunset: 6:00 pm ChST
  • ▼
  • Tuesday
  • Oct 20, 2026
  • 84°F
  • 79°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 14%
  • Precipitation: 0"
  • Wind: 12mphESE 111°
  • Humidity: 82%
  • UV index: 10
  • Sunrise: 6:12 am ChST
  • Sunset: 5:59 pm ChST
  • ▼
  • Wednesday
  • Oct 21, 2026
  • 84°F
  • 77°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 22%
  • Precipitation: 0.04"
  • Wind: 11mphNE 56°
  • Humidity: 82%
  • UV index: 10
  • Sunrise: 6:12 am ChST
  • Sunset: 5:59 pm ChST
  • ▼
  • Thursday
  • Oct 22, 2026
  • 84°F
  • 77°F
Mostly Sunny
Mostly Sunny
  • Precip. probability: 24%
  • Precipitation: 0.08"
  • Wind: 12mphNE 55°
  • Humidity: 82%
  • UV index: 11
  • Sunrise: 6:12 am ChST
  • Sunset: 5:58 pm ChST
  • ▼
  • Friday
  • Oct 23, 2026
  • 84°F
  • 79°F
Mostly Sunny
Mostly Sunny
  • Precip. probability: 24%
  • Precipitation: 0.2"
  • Wind: 12mphENE 64°
  • Humidity: 83%
  • UV index: 11
  • Sunrise: 6:13 am ChST
  • Sunset: 5:58 pm ChST
  • ▼
  • Saturday
  • Oct 24, 2026
  • 84°F
  • 79°F
Showers
Showers
  • Precip. probability: 47%
  • Precipitation: 0.28"
  • Wind: 11mphENE 75°
  • Humidity: 84%
  • UV index: 11
  • Sunrise: 6:13 am ChST
  • Sunset: 5:57 pm ChST
  • ▼
  • Sunday
  • Oct 25, 2026
  • 84°F
  • 77°F
Showers
Showers
  • Precip. probability: 41%
  • Precipitation: 0.24"
  • Wind: 8mphE 83°
  • Humidity: 83%
  • UV index: 10
  • Sunrise: 6:13 am ChST
  • Sunset: 5:57 pm ChST
  • ▼
  • Monday
  • Oct 26, 2026
  • 84°F
  • 77°F
Showers
Showers
  • Precip. probability: 43%
  • Precipitation: 0.12"
  • Wind: 7mphENE 73°
  • Humidity: 82%
  • UV index: 11
  • Sunrise: 6:13 am ChST
  • Sunset: 5:56 pm ChST
  • ▼
During the ten-day period, wet, cloud-filled and clear weather is anticipated.
Rain is expected on Saturday through Monday, Wednesday through next Monday.
The temperature shift across days will be subtle in the upcoming days. Expected highs will hover between 80.6°F and 84.2°F, while fluctuations in the night’s lowest temperature will be also minimal, as the minimum temperature will fluctuate between 77°F and 78.8°F.
Tuesday through next Monday, with the highest temperature of 84.2°F, will be the hottest days in Umatac, Guam; Sunday will be the coldest day, with the highest temperature of 80.6°F.
Taking the humidity into consideration, the maximum feel-like temperature may increase considerably and range between a hot 87.8°F and a fiery hot 96.8°F.
Updated: Oct 17, 2026 @ 13:47:11 UTC
Published by: Weather U.S. | About Us
Data Sources | weather.com | Weather
Weather Forecasting & Climate

Frequently asked questions

On Sunday, wind-driven rainfall is anticipated, requiring rain gear and extra caution on the roads.

Yes, it will rain tomorrow. Weather alert - extreme precipitation of 4.8" is anticipated.

Tomorrow, the maximum temperature will be 80.6°F, while the minimum temperature will be 78.8°F. The maximum heat index, which combines air temperature and relative humidity, is estimated at 87.8°F.
Tomorrow, the highest temperature will be moderately lower than the average maximum temperature in October. The lowest temperature tomorrow will be also moderately lower than the average low temperature.

On Sunday, in Umatac, sunrise will be at 6:12 am and sunset at 6:00 pm (ChST).

Tomorrow in Umatac, the daylight will last for 11h and 49min.