Guam Weather & Climate 2026

Am Tropical Monsoon

Monthly climate averages for Hagåtña. Based on 10-year ERA5 reanalysis data.

January February March April May June July August September October November December

Climate Overview

Guam experiences average highs of 28°C (82°F) and lows of 27°C (81°F) throughout the year. Rainfall is frequent, averaging about 21 rainy days per month. Sunshine is abundant, averaging about 11 hours per day. High humidity combined with warm temperatures produces a tropical feel year-round. Average highs have stayed broadly stable across the available records.

Drier season: Jan–Dec Wetter season: Jun–Nov

At-a-Glance Climate Summary

Jan 6.9/10 Feb 6.9/10 Mar 6.1/10 Apr 5.8/10 May 5/10 Jun 4.3/10 Jul 4.1/10 Aug 3.7/10 Sep 3.7/10 Oct 3.9/10 Nov 3.9/10 Dec 5/10

Key figures

Climate Score
4.9/10
Best: January, February
UV Index
—
Low
Temperature 28°C / 27°C
Feels Like 32°C / 29°C
Rainy Days 21
Rainfall 181 mm
Sunshine 11 h
Humidity 82%
Wind Speed 29 km/h
Dew Point 24°C
Best Time to Visit
JFMAMJJASOND
Recommended
Hottest Month
29°C
November
Avg Low27°C
Rain25days
Coldest Month
26°C
February
Avg High27°C
Rain12days
Driest Month
12days
February
Avg High27°C
Avg Low26°C
Windiest Month
36 km/h
February (Gusts 48)

Worst Time to Visit

Consider avoiding August, September, October, November due to heavy rainfall, oppressive humidity.

LIVE Current Weather Local Time
LIVE Air Quality
Sun Position
Sunrise 05:55
Daylight 12.9h
Sunset 18:50

Showing the live 14-day forecast for Hagåtña, not a single forecast for all of Guam.

14-Day Forecast

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City forecasts

14-day forecasts for major cities in Guam

Weather changes by city, coast, elevation, and region. Use these live previews for populated places in Guam, then open a city page for the full forecast.

Hagåtña

Population: 1.1K

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Dededo Village

Population: 44.9K

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Yigo Village

Population: 20.5K

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Tamuning

Population: 19.7K

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Tamuning-Tumon-Harmon Village

Population: 19.7K

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Mangilao Village

Population: 15.2K

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Seasonal Breakdown

Spring
Mar–May
Avg High 28°C
Avg Low 27°C
Rain 15 days/mo
Summer
Jun–Aug
Avg High 28°C
Avg Low 27°C
Rain 27 days/mo
Autumn
Sep–Nov
Avg High 29°C
Avg Low 27°C
Rain 27 days/mo
Winter
Dec–Feb
Avg High 28°C
Avg Low 26°C
Rain 15 days/mo
2/3 best months

Based on historical averages (2016–2025)

Monthly Temperatures

36°C 30°C 24°C 18°C JanFebMarAprMayJunJulAugSepOctNovDec
HighLowShaded bands show the typical range across the available yearly records.

Monthly Rainfall

0 mm 70 mm 140 mm 210 mm 280 mm 350 mm JanFebMarAprMayJunJulAugSepOctNovDec
Rainfall

Monthly Humidity

0% 25% 50% 75% 100% JanFebMarAprMayJunJulAugSepOctNovDec
Humidity

Monthly Wind Speed

0 15 30 45 60 JanFebMarAprMayJunJulAugSepOctNovDec
Wind SpeedGusts

Sunshine

0 3 6 9 12 JanFebMarAprMayJunJulAugSepOctNovDec
Sunshine

Monthly Daylight Hours

14h 12h 10h JanFebMarAprMayJunJulAugSepOctNovDec
Daylight12h reference

Monthly Dew Point & Comfort

32°C 28°C 24°C 20°C 16°C 12°C 8°C 4°C 0°C -4°C JanFebMarAprMayJunJulAugSepOctNovDec
Dew Point Dry Comfortable Humid Muggy

Month-by-Month Weather Table

January best
Good
Temp
28°C / 26°C
Feels Like
30°C / 27°C
Rain
14days (81 mm) Wet
Sun
10.7h Excellent
Humidity
80% Humid
View Details
February best
Good
Temp
27°C / 26°C
Feels Like
29°C / 27°C
Rain
12days (59 mm) Wet
Sun
10.8h Excellent
Humidity
79% Humid
View Details
March
Fair
Temp
27°C / 26°C
Feels Like
30°C / 28°C
Rain
13days (44 mm) Wet
Sun
11.3h Excellent
Humidity
81% Humid
View Details
April
Fair
Temp
28°C / 27°C
Feels Like
32°C / 29°C
Rain
15days (84 mm) Wet
Sun
11.6h Excellent
Humidity
82% Humid
View Details
May
Fair
Temp
28°C / 27°C
Feels Like
32°C / 29°C
Rain
17days (117 mm) Wet
Sun
11.9h Excellent
Humidity
82% Humid
View Details
June
Wet
Temp
28°C / 27°C
Feels Like
33°C / 30°C
Rain
22days (175 mm) Wet
Sun
11.4h Excellent
Humidity
82% Humid
View Details
July
Wet
Temp
29°C / 27°C
Feels Like
33°C / 30°C
Rain
29days (268 mm) Wet
Sun
10.1h Excellent
Humidity
84% Humid
View Details
August
Wet
Temp
29°C / 27°C
Feels Like
34°C / 30°C
Rain
29days (311 mm) Wet
Sun
9.4h Good
Humidity
83% Humid
View Details
September
Wet
Temp
29°C / 27°C
Feels Like
34°C / 30°C
Rain
28days (333 mm) Wet
Sun
9.1h Good
Humidity
83% Humid
View Details
October
Wet
Temp
28°C / 27°C
Feels Like
33°C / 30°C
Rain
29days (409 mm) Wet
Sun
8.8h Good
Humidity
84% Humid
View Details
November
Wet
Temp
29°C / 27°C
Feels Like
32°C / 29°C
Rain
25days (184 mm) Wet
Sun
10.3h Excellent
Humidity
83% Humid
View Details
December
Wet
Temp
28°C / 27°C
Feels Like
31°C / 29°C
Rain
20days (110 mm) Wet
Sun
10.7h Excellent
Humidity
81% Humid
View Details
Month Temp Feels Like Rain Sun Humidity Status
January best 28°C / 26°C 30°C / 27°C 14days (81 mm) Wet 10.7h Excellent 80% Humid Good View Details
February best 27°C / 26°C 29°C / 27°C 12days (59 mm) Wet 10.8h Excellent 79% Humid Good View Details
March 27°C / 26°C 30°C / 28°C 13days (44 mm) Wet 11.3h Excellent 81% Humid Fair View Details
April 28°C / 27°C 32°C / 29°C 15days (84 mm) Wet 11.6h Excellent 82% Humid Fair View Details
May 28°C / 27°C 32°C / 29°C 17days (117 mm) Wet 11.9h Excellent 82% Humid Fair View Details
June 28°C / 27°C 33°C / 30°C 22days (175 mm) Wet 11.4h Excellent 82% Humid Wet View Details
July 29°C / 27°C 33°C / 30°C 29days (268 mm) Wet 10.1h Excellent 84% Humid Wet View Details
August 29°C / 27°C 34°C / 30°C 29days (311 mm) Wet 9.4h Good 83% Humid Wet View Details
September 29°C / 27°C 34°C / 30°C 28days (333 mm) Wet 9.1h Good 83% Humid Wet View Details
October 28°C / 27°C 33°C / 30°C 29days (409 mm) Wet 8.8h Good 84% Humid Wet View Details
November 29°C / 27°C 32°C / 29°C 25days (184 mm) Wet 10.3h Excellent 83% Humid Wet View Details
December 28°C / 27°C 31°C / 29°C 20days (110 mm) Wet 10.7h Excellent 81% Humid Wet View Details

Best Time to Visit Guam (2026)

Frequently Asked Questions

The best months to visit Guam are January, February, when temperatures are comfortable and rainfall is at its lowest. This is based on 10-year climate averages for Hagåtña, scoring temperature, rainfall, humidity, and sunshine hours.
The hottest month in Guam is November, with average daytime highs of 29°C (83°F). Plan outdoor activities for early morning or late afternoon if visiting during this period.
The coldest month in Guam is February, with average overnight lows of 26°C (79°F). Pack warm layers and expect shorter daylight hours during this period.
The wettest month in Guam is October, averaging 409mm of precipitation across 29 rainy days. An umbrella or waterproof jacket is essential.
The rainy season in Guam runs through July, August, October, September, with the heaviest rainfall in July. Based on 10-year averages for Hagåtña.
Guam receives approximately 126 sunshine hours per year. The sunniest month is May with around 12 hours. Based on climate data for Hagåtña.
The least favorable months to visit Guam are August, September, October, November, primarily due to heavy rainfall, oppressive humidity. For the best conditions, consider January, February instead.
Average humidity in Guam is 82%, classified as humid. High humidity makes warm temperatures feel significantly hotter — lightweight, breathable clothing is recommended.
Average wind speeds in Guam are 29 km/h (18 mph). The windiest month is February with peak winds reaching 36 km/h (23 mph) (gusts up to 48 km/h / 30 mph).
Guam averages 1 clear-sky days per month with overall cloud cover around 64%. The clearest skies occur in March.
The annual average dew point in Guam is 24°C (75°F), which feels oppressively humid. Expect heavy perspiration during warmer months — stay hydrated and take breaks in air-conditioned spaces.
Guam has a Tropical Monsoon climate, classified as Am under the Köppen system. Tropical climates are warm year-round with high rainfall and temperatures rarely dropping below 18°C (64°F).
The 'feels like' temperature in Guam ranges from 29°C (84°F) to 32°C (90°F) on average. Humidity and radiant heat mean it often feels warmer than the thermometer reads, especially in summer months.
June is not the best time to visit Guam, with a climate score of 4.3/10. Consider visiting during January, February instead for better conditions.
For June in Guam, pack Umbrella, Waterproof jacket, Waterproof shoes, Breathable clothing, Sunscreen (SPF 30+). With average highs of 28°C (83°F) and 22 rainy days, these essentials will keep you comfortable.

Data Source

Climate data derived from ERA5 reanalysis (ECMWF), averaged over 2016–2025. Sea surface temperature from marine reanalysis data. Climate scores and seasonal estimates are computed by WorldStats.

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