Hagåtña climate

Name: Hagåtña
Address: GU

Hagåtña is warmest in June, with average highs of 29 °C, and coldest in February, when nights average 25 °C. August is the wettest month (372 mm) and March the driest (48 mm). Figures are 1991–2020 climate normals.

Across a full year Hagåtña averages 2,074 mm of rain and 365 days above 25 °C.

Guam · 3 m elevation · population 1,051 · 1991–2020 normals

Temperature below 0 °C to above 30 °C Rain band height is that month’s share of the wettest month

Warmest month June 29 °C
Coldest month February 25 °C
Driest month March 48 mm
Wettest month August 372 mm
Least cloud April 50 % cloud
Hottest on record May 32 °C
Coldest on record March 22 °C
Warmest sea July 29 °C

What to expectHagåtña through the year

Hagåtña changes little through the year. Average daily highs stay between 27 and 29 °C, so no month stands out as a season in the way it would further from the equator.

Counted across a normal year, 365 days a year reach 25 °C, 18 of them reach 30 °C. The warmest reading in the 1991–2020 record is 32 °C, in May.

Rain is strongly seasonal. August averages 372 mm against 48 mm in March — 7.7 times as much. Planning around the dry months matters more here than planning around temperature.

The sea off Hagåtña is warmest in July at 29 °C and coldest in February at 28 °C. Sea temperature lags the air by a month or two, which is why late summer swims warmer than early summer at the same air temperature.

Month by month

Month	Avg high	Rainfall	Cloud
January	27.5 °C	75 mm	53 %
February	27.3 °C	56 mm	52 %
March	27.6 °C	48 mm	50 %
April	28.2 °C	74 mm	50 %
May	28.6 °C	91 mm	57 %
June	28.8 °C	149 mm	64 %
July	28.6 °C	294 mm	81 %
August	28.5 °C	372 mm	87 %
September	28.5 °C	342 mm	86 %
October	28.4 °C	297 mm	76 %
November	28.5 °C	178 mm	56 %
December	28.1 °C	99 mm	51 %

Temperature month by month

Month	Avg high	Avg low	Mean	Record high	Record low	Days above 25 °C	Days above 30 °C
January	27.5 °C	25.6 °C	26.5 °C	30.4 °C	22.8 °C	31	0
February	27.3 °C	25.4 °C	26.3 °C	30.7 °C	22.9 °C	28	0
March	27.6 °C	25.6 °C	26.5 °C	30.8 °C	22.4 °C	31	1
April	28.2 °C	26.0 °C	27.0 °C	31.1 °C	23.1 °C	30	2
May	28.6 °C	26.3 °C	27.4 °C	32.1 °C	23.7 °C	31	3
June	28.8 °C	26.4 °C	27.6 °C	31.9 °C	23.6 °C	30	3
July	28.6 °C	26.0 °C	27.3 °C	32.1 °C	23.8 °C	31	2
August	28.5 °C	25.9 °C	27.1 °C	31.7 °C	23.5 °C	31	2
September	28.5 °C	25.9 °C	27.1 °C	32.0 °C	23.2 °C	30	2
October	28.4 °C	26.0 °C	27.2 °C	32.1 °C	23.0 °C	31	1
November	28.5 °C	26.3 °C	27.3 °C	31.4 °C	23.9 °C	30	2
December	28.1 °C	26.2 °C	27.1 °C	30.7 °C	23.7 °C	31	0

Rain, sun and wind month by month

Month	Rainfall	Wet days	Daylight	Cloud cover	Humidity	Wind	Sea temp
January	75 mm	14	11 h/day	53 %	79 %	32 km/h	27.9 °C
February	56 mm	12	12 h/day	52 %	78 %	32 km/h	27.6 °C
March	48 mm	10	12 h/day	50 %	78 %	31 km/h	27.7 °C
April	74 mm	12	12 h/day	50 %	80 %	28 km/h	28.1 °C
May	91 mm	15	13 h/day	57 %	81 %	25 km/h	28.8 °C
June	149 mm	20	13 h/day	64 %	82 %	25 km/h	29.3 °C
July	294 mm	28	13 h/day	81 %	84 %	23 km/h	29.4 °C
August	372 mm	29	13 h/day	87 %	85 %	23 km/h	29.4 °C
September	342 mm	27	12 h/day	86 %	84 %	23 km/h	29.4 °C
October	297 mm	27	12 h/day	76 %	84 %	25 km/h	29.3 °C
November	178 mm	20	12 h/day	56 %	83 %	30 km/h	29.0 °C
December	99 mm	15	11 h/day	51 %	81 %	32 km/h	28.4 °C

Planning a trip? See the best time to visit Hagåtña.

QuestionsCommon questions about Hagåtña’s climate

When is the best time to visit Hagåtña?

That depends on what you want, so the honest answer is a comparison rather than a single month. January, February, March sit closest to 20 °C on average, June is the warmest month and March the driest. The month-by-month table above has the full picture.

How hot does Hagåtña get?

In June, the warmest month, daily highs average 29 °C. About 18 days a year pass 30 °C. The highest value in the 1991–2020 record is 32 °C.

How cold does it get in winter?

Nights average 25 °C in February, the coldest month. Freezing nights are not part of a normal year here.

Which month is wettest in Hagåtña?

August, averaging 372 mm over 29 days with rain. The driest month is March with 48 mm. The year as a whole averages 2,074 mm.

Are these figures a forecast?

No. They are 1991–2020 climate normals: the average of thirty years, which describes what a month is usually like in Hagåtña rather than what any particular week will bring. Individual years can differ substantially from the normal.

Data sources and method

ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
Open-Meteo — Open-Meteo.com. CC BY 4.0
NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
GeoNames — GeoNames.org. CC BY 4.0

Normal period: 1991–2020
Data point: 13.476°, 144.749° , 3 m above sea level (the coordinates the reanalysis values are taken for)
Dataset version: era5-1991-2020-scores1.1
Last processed: 1 August 2026

Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: monthly rankings, daylight hours, beach and comfort scores. Full formulas are on the methodology page.

Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.