Weather in Guam in September
Country-wide climate normals across 15 cities in Guam.
How Hot Is Guam in September?
Uniform heat across Guam's September: averages climb to 29°C nationally with overnight lows of 26°C, narrow spread from coast to interior. The hottest cities like Agat Village register similar readings to the coolest, so plan for consistently hot weather across the country.
Sunshine in Guam in September
Guam sees limited sun in September: just 0.7h a day in Dededo Village, with heavy cloud cover common across most regions. Daylight runs from 6:10 am to 6:20 pm, but persistent grey skies and overcast stretches mean direct sunlight is genuinely scarce. Many days pass without any prolonged sunny spells.
Does It Rain In Guam In September?
Guam is in the heart of its rainy season: Dededo Village measures 522mm of rain across 29 days in September, and the pattern repeats across nearly all regions. Persistent heavy rain, occasional thunderstorms, and saturated air define the entire country's weather.
Is Guam Humid In September?
Heavy oppressive humidity covers Guam in September: 77% on average in Dededo Village, and similar saturating conditions exist nationwide. The air feels thick and heavy from sunrise to sundown, with little overnight respite. Coastal and tropical regions feel especially stifling.
Wind In Guam In September
Light breezes are typical across Guam in September: 20 kph in Dededo Village, with similar gentle wind conditions in most regions. The air moves enough to keep things fresh on warm days but not enough to be disruptive. Coastal cities may see slightly more.
Cloud Cover In Guam In September
Heavy overcast covers Guam in September: 79% cloud cover in Dededo Village, with similar grey conditions in most regions. Direct sun is rare, and the pattern is persistent across the country. Coastal and northern regions feel especially heavy.