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Monthly climate in Hagatna, Guam

Last updated: July 31, 2025

Under the Köppen–Geiger climate classification Hagatna features a tropical rainforest climate (Af). Temperatures typically range between 27 °C (80 °F) and 28 °C (82 °F) through the year, but rarely can drop to 25 °C (77 °F) or can rise to as high as 30 °C (86 °F). The average annual precipitation amounts to about 2241 mm (88.2 inches) and receives 273 rainy days on the 1 mm (0.04 inches) threshold annually. Hagatna enjoys an average of 3441 hours of sunshine throughout the year, and daylight varies from 11 hours 20 minutes to 12 hours 53 minutes per day.

Monthly average temperatures in Hagatna, Guam

The warmest months in Hagatna are May, June and November, with daily mean temperatures ranging from 28 to 28 °C (82 - 82 °F) throughout the day. The coldest temperatures usually occur in January, February and March, when daily mean temperatures range from 27 to 27 °C (80 - 81 °F) throughout the day. On average each year, Hagatna experiences 329 days above 25 °C (77.0 °F) and 0 days below 0 °C (32.0 °F).

Monthly average temperatures with daily means, minimums and maximums for period, average high and low temperatures in Hagatna. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to June 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Maximum28°C
(83°F)		28°C
(83°F)		28°C
(83°F)		29°C
(84°F)		29°C
(84°F)		29°C
(85°F)		29°C
(85°F)		29°C
(85°F)		30°C
(86°F)		29°C
(85°F)		29°C
(85°F)		29°C
(84°F)
Mean maximum28°C
(83°F)		28°C
(82°F)		28°C
(82°F)		28°C
(83°F)		29°C
(84°F)		29°C
(84°F)		29°C
(85°F)		29°C
(85°F)		29°C
(85°F)		29°C
(85°F)		29°C
(84°F)		29°C
(84°F)
Average high27°C
(82°F)		27°C
(81°F)		27°C
(81°F)		28°C
(82°F)		28°C
(83°F)		28°C
(83°F)		28°C
(83°F)		28°C
(83°F)		28°C
(83°F)		28°C
(83°F)		28°C
(83°F)		28°C
(83°F)
Daily mean27°C
(81°F)		27°C
(80°F)		27°C
(81°F)		27°C
(81°F)		28°C
(82°F)		28°C
(82°F)		28°C
(82°F)		28°C
(82°F)		28°C
(82°F)		28°C
(82°F)		28°C
(82°F)		27°C
(82°F)
Average low26°C
(79°F)		26°C
(79°F)		26°C
(79°F)		26°C
(80°F)		27°C
(80°F)		27°C
(81°F)		27°C
(80°F)		26°C
(80°F)		26°C
(80°F)		27°C
(80°F)		27°C
(81°F)		27°C
(80°F)
Mean minimum25°C
(78°F)		25°C
(78°F)		25°C
(78°F)		25°C
(78°F)		26°C
(79°F)		26°C
(79°F)		26°C
(79°F)		26°C
(78°F)		26°C
(78°F)		26°C
(78°F)		26°C
(79°F)		26°C
(79°F)
Minimum25°C
(77°F)		25°C
(78°F)		25°C
(77°F)		25°C
(77°F)		25°C
(78°F)		25°C
(78°F)		26°C
(78°F)		25°C
(78°F)		25°C
(77°F)		25°C
(78°F)		26°C
(79°F)		26°C
(78°F)

Compare climate in Hagatna with other places

Compare temperature, precipitation, sunshine, UV index in Hagatna, Guam with other places around the world.

Monthly average precipitation in Hagatna, Guam

Hagatna usually has the most precipitation in August, September and October, with an average of 29 rainy days and 379 mm (14.9 inches) of precipitation per month. The driest months in Hagatna are January, February and March. On average, 63 mm (2.5 inches) of precipitation falls during these months.

Monthly average precipitation and precipitation days in Hagatna. Generated using Copernicus Climate Change Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Average precipitation mm (inches)61 (2.4)77 (3.0)53 (2.1)94 (3.7)78 (3.1)159 (6.3)276 (10.9)405 (16.0)375 (14.8)356 (14.0)202 (8.0)105 (4.1)
Average precipitation days (≥ 1 mm)151515182223303028292622

Monthly sunshine hours in Hagatna, Guam

The sunniest months in Hagatna are March, May and June, when the sun shines an average of 10 hours 33 minutes a day. Least sunny months in Hagatna: January, September and October receive an average of 8 hours 12 minutes of sunshine daily.

Mean monthly sunshine duration, average sunshine hours per day and mean daily daylight hours in Hagatna. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2017 to January 2022.
 JanFebMarAprMayJunJulAugSepOctNovDec
Mean monthly sunshine hours232266316314336318299269259263279285
Mean daily daylight hours11h 24m11h 41m12h 2m12h 25m12h 44m12h 53m12h 48m12h 32m12h 10m11h 48m11h 29m11h 20m

Solar UV radiation in Hagatna, Guam

Hagatna experiences the highest level of ultraviolet (UV) radiation in March, April and September, when the maximum UV index can reach values of 15 - 15, which corresponds to the Extreme category of sun exposure. January, November and December are in the Extreme exposure category. In these months, the maximum values of the UV index do not exceed 12. For more detailed information, check out our hourly Hagatna UV Index data.

Average daily maximum UV levels by month for Hagatna. Generated using Copernicus Atmosphere Monitoring Service information. Data for period from January 2022 to January 2023.
 JanFebMarAprMayJunJulAugSepOctNovDec
UV Index (month maximum)111315151314141415131211