Climate and monthly weather forecastUmatac, GU
Climate and monthly weather forecast
The climate of Umatac
The climate of Umatac, of the tropical rainforest type as classified by the Köppen climate classification system, primarily features high humidity, abundant rainfall, and consistently high temperatures throughout the year. Situated in the geographical location of Guam, USA, Umatac experiences a climate condition that is broadly equatorial.Throughout the year, Umatac's weather shows a characteristically low fluctuation. The high temperatures range from 81.7°F (27.6°C) to 84.7°F (29.3°C), whereas the low temperatures show a marginal variation from 79.7°F (26.5°C) to 83.3°F (28.5°C). The relative humidity stays stable from 76% to 78%.
An important factor in Umatac's climate is the abundant rainfall, varying from 1.81" (46mm) to 10.28" (261mm) throughout the year. A high concentration of precipitation occurs, particularly from July to October. The frequency of rainfall days varies, with a peak of 28.9 days a month seen from July to August.
The daylight hours remain close to 12 hours throughout the year, varying from 11.4 hours to 12.9 hours. Direct sunshine hours tend to dip to a low of 6.3 hours in November while peaking at 10.6 hours in June.
The average wind speed varies from 9.6mph (15.4km/h) to 16.3mph (26.2km/h), while gusts can reach up to 22.2mph (35.7km/h), especially between January and February. A unique pattern seen in Umatac's weather is the significant decrease in wind speed from May to September.
The best time to visit Umatac
The best time to visit Umatac depends greatly on weather preferences. Given the stability in temperature, suitable travel times may vary based on other components of climate. However, considering the various climate aspects, March appears to be the most suitable time for many tourists. March records a relatively low rainfall of 1.81" (46mm), fewer rainfall days (20.2 days), and receives moderate sunshine hours of 8.1 hours, providing favorable weather conditions for a visit.The worst time to visit Umatac
On the contrary, for those planning to avoid excessive rainfall, a trip to Umatac from July to October might not be ideal. During this period, rainfall levels peak, with August registering the highest rainfall figure of 10.28" (261mm) and rainfall days reaching the maximum of 28.9 days. Coupled with the lowest sunshine hours, tourists might find outdoor activities limited.Spring weather in Umatac
Umatac's spring, from March to May, greets the arrival of moderately pleasant weather. The temperature ranges from 82°F (27.8°C) to 84.2°F (29°C) for high and from 80.1°F (26.7°C) to 82.2°F (27.9°C) for low. Spring sees moderately low rainfall, between 1.81" (46mm) to 3.31" (84mm) with the number of rainfall days ranging from 20.2 days to 23.1 days. On the other hand, the number of sunshine hours increases, culminating in 10.5 hours in May, further enhancing the viability of outdoor activities.Summer weather in Umatac
Umatac's summer from June to August is characterized by high rainfall. The rainfall steadily increases from 3.7" (94mm) to 9.76" (248mm) in the course of these months, with an increase in the number of rainfall days from 25.4 days to 28.9 days. Despite maintaining a steady high temperature from 84.6°F (29.2°C) to 84.7°F (29.3°C) and a low temperature of around 82.9°F (28.3°C), the decrease in sunshine hours from 10.6 hours to 7.6 hours calls for preparedness for wet weather outdoor plans.Autumn weather in Umatac
The autumn months of September to November in Umatac are led by a consistent high rainfall, particularly in September, which records a whopping 10.28" (261mm). The temperature remains fairly consistent with high temperatures from 84.4°F (29.1°C) to 84.2°F (29°C) and low temperatures around 82.6°F (28.1°C) to 82.8°F (28.2°C). One may notice a decrease in daylight hours from 12.2 hours to 11.5 hours and a decrease in sunshine hours from 7.9 hours to 6.3 hours.Winter weather in Umatac
December to February, the winter months in Umatac, welcome slightly lower rainfall than the preceding months, varying from 2.83" (72mm) to 2.99" (76mm). The temperature during these months ranges from 82°F (27.8°C) for highs to around 80.6°F (27°C) for lows. Simultaneously, the daylight hours remain fairly constant around 11.5 hours to 11.7 hours. The sunshine hours though, show a slight increase from 6.3 hours to 7.6 hours offering brighter days.Weather in January
January in Umatac, Guam, ushers in the new year accompanied by warm temperatures, slight humidity, and moderate rainfall. In comparison to February, January records notably higher rainfall at 2.83" (72mm) and wind speeds of 15.8mph (25.4km/h). Weather in January »Weather in February
Weather conditions in February in Umatac, Guam, tend to retain most characteristics witnessed in January. However, a marginal dip in rainfall to 2.28" (58mm) differentiates February from its preceding month. The atmosphere reins in a soothing harmony of sunshine, gentle winds, and decreased humidity. Weather in February »Weather in March
Transitioning into March, Umatac, Guam experiences a minor reduction in recorded rainfall and humidity. Subsequent to the moderate decline of precipitation to 1.81" (46mm), March becomes notably drier compared to February. On the flip side, there is an increase in sunshine hours providing an ideal setting for beach visits and picnics. Weather in March »Weather in April
The weather in Umatac, Guam throughout April involves a significant increase in rainfall, notching up at 2.44" (62mm) from the preceding month's low. This heightened precipitation heralds the imminent arrival of the rainy season. Weather in April »Weather in May
As May rolls in, Umatac, Guam welcomes increased rainfall, registering at a high of 3.31" (84mm), a significant leap from April. This surge underscores the ongoing shift towards the inclemency of the rainy season. Amidst this, the weather tames the turbulent winds, making way for a noticeable drop in wind speed. Weather in May »Weather in June
June in Umatac, Guam, is characterized by further ascendance in rainfall, reaching a value of 3.7" (94mm). This month witnesses a marked leap from the reduced showers of May, hinting towards a transition into the more intense period of the rainy season. Weather in June »Weather in July
July's weather steadily escalates in intensity, with Umatac, Guam experiencing a peak rainfall of 7.52" (191mm), significantly exceeding June's precipitation. The city braves the zenith of the rainy season amid this month, yet warmth and humidity persist. Weather in July »Weather in August
Come August, Umatac, Guam endures its wettest episode with rainfall peaking at a high of 9.76" (248mm), slightly above what is recorded in July. The high rainfall makes this month a prominent part of the rainy season. However, the city's climate offsets the high precipitation with decreased wind speed. Weather in August »Weather in September
September weather in Umatac, Guam juxtaposes elevated rainfall, peaking at 10.28" (261mm) alongside significantly reduced sunshine. This denotes a continuation of the rainy season, with rainfall being the most distinguishing feature, even when compared to August. Weather in September »Weather in October
October in Umatac, Guam indicates a retreat in rainfall, tapering off to 8.46" (215mm) in a minor step down from September. Despite this decrease, October retains its place in the rainy season procession. The cloud percentage continues to dominate, which in collaboration with tempered wind speeds, gives rise to a subdued tropical mood. Weather in October »Weather in November
November hosts a significant reduction in rainfall to 4.69" (119mm), marking a shift away from the heavy precipitation of the prior months. The evident downfall in rainfall, compared to October, signifies a gradual approach towards the termination of the rainy season. Weather in November »Weather in December
Rounding off the year, December in Umatac, Guam features a further decline in rainfall to 2.99" (76mm), a drop from November's already reduced precipitation. This downward trend marks the cessation of the rainy season. Despite a decrease in glory, the weather radiates a gentle elegance with its subtropical warmth and winds. Weather in December »Updated: Aug 7, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
The months with the highest humidity are January, March through May, October through December, with an average relative humidity of 78%.
Throughout the year, there are 288.5 rainfall days, and 60.08" (1526mm) of precipitation is accumulated.
The months with the highest UV index are January through August, October through December, with an average maximum UV index of 7.
The coldest month is February, with an average high-temperature of 81.7°F (27.6°C) and an average low-temperature of 79.7°F (26.5°C).
The month with the least rainfall is March, when the rain falls for 20.2 days and typically collects 1.81" (46mm) of precipitation.
June has the longest days of the year, with an average of 12h and 54min of daylight.
With an average of 10.6h of sunshine, June has the most sunshine of the year.
During July and August, Umatac experiences its warmest period, with an average high-temperature of 84.7°F (29.3°C).
With an average relative humidity of 76%, August is the least humid month.
September is the month with the most rainfall. Rain falls for 28.1 days and accumulates 10.28" (261mm) of precipitation.
With an average maximum UV index of 6, September is the month with the lowest UV index.
With an average of 6.3h of sunshine, November has the least sunshine of the year.
December has the shortest days of the year, with an average of 11h and 24min of daylight.
Umatac does not utilize Daylight Saving Time (DST). ChST timezone is used throughout the entire year.
Average temperature
Umatac, GU
The warmest months (with the highest average high temperature) are July and August (84.7°F).
The month with the lowest average high temperature is February (81.7°F).
The month with the highest average low temperature is June (83.3°F).
The coldest month (with the lowest average low temperature) is February (79.7°F).
Average pressure
Umatac, GU
- Average pressure in January:
29.86"Hg - Average pressure in February:
29.88"Hg - Average pressure in March:
29.87"Hg - Average pressure in April:
29.86"Hg - Average pressure in May:
29.85"Hg - Average pressure in June:
29.84"Hg
- Average pressure in July:
29.8"Hg - Average pressure in August:
29.79"Hg - Average pressure in September:
29.79"Hg - Average pressure in October:
29.79"Hg - Average pressure in November:
29.82"Hg - Average pressure in December:
29.83"Hg
The month with the highest atmospheric pressure is February (29.88"Hg).
The months with the lowest atmospheric pressure are August, September and October (29.79"Hg).
Average wind speed
Umatac, GU
- Average wind speed in January:
15.8mph - Average wind speed in February:
16.3mph - Average wind speed in March:
15mph - Average wind speed in April:
13.7mph - Average wind speed in May:
11.7mph - Average wind speed in June:
11.6mph
- Average wind speed in July:
10.3mph - Average wind speed in August:
9.6mph - Average wind speed in September:
9.9mph - Average wind speed in October:
11.2mph - Average wind speed in November:
14.7mph - Average wind speed in December:
15.7mph
The windiest month (with the highest average wind speed) is February (16.3mph).
The calmest month (with the lowest average wind speed) is August (9.6mph).
Average humidity
Umatac, GU
The months with the highest relative humidity are January, March, April, May, October, November and December (78%).
The month with the lowest relative humidity is August (76%).
Average rainfall
Umatac, GU
- Average rainfall in January:
2.83" - Average rainfall in February:
2.28" - Average rainfall in March:
1.81" - Average rainfall in April:
2.44" - Average rainfall in May:
3.31" - Average rainfall in June:
3.7"
- Average rainfall in July:
7.52" - Average rainfall in August:
9.76" - Average rainfall in September:
10.28" - Average rainfall in October:
8.46" - Average rainfall in November:
4.69" - Average rainfall in December:
2.99"
The wettest month (with the highest rainfall) is September (10.28").
The driest month (with the least rainfall) is March (1.81").
Average rainfall days
Umatac, GU
- Average rainfall days in January:
21.3 days - Average rainfall days in February:
17.5 days - Average rainfall days in March:
20.2 days - Average rainfall days in April:
19.3 days - Average rainfall days in May:
23.1 days - Average rainfall days in June:
25.4 days
- Average rainfall days in July:
28.9 days - Average rainfall days in August:
28.9 days - Average rainfall days in September:
28.1 days - Average rainfall days in October:
28.7 days - Average rainfall days in November:
24.3 days - Average rainfall days in December:
22.8 days
The months with the highest number of rainy days are July and August (28.9 days).
The month with the least rainy days is February (17.5 days).
Average daylight / Average sunshine
Umatac, GU
- Average daylight in January:
11h and 24min - Average daylight in February:
11h and 42min - Average daylight in March:
12h and 6min - Average daylight in April:
12h and 24min - Average daylight in May:
12h and 42min - Average daylight in June:
12h and 54min
- Average daylight in July:
12h and 48min - Average daylight in August:
12h and 36min - Average daylight in September:
12h and 12min - Average daylight in October:
11h and 48min - Average daylight in November:
11h and 30min - Average daylight in December:
11h and 24min
The month with the longest days is June (Average daylight: 12h and 54min).
The month with the shortest days is December (Average daylight: 11h and 24min).
- Average sunshine in January:
7h and 36min - Average sunshine in February:
8h and 0min - Average sunshine in March:
8h and 6min - Average sunshine in April:
8h and 30min - Average sunshine in May:
10h and 30min - Average sunshine in June:
10h and 36min
- Average sunshine in July:
8h and 36min - Average sunshine in August:
7h and 36min - Average sunshine in September:
7h and 54min - Average sunshine in October:
6h and 54min - Average sunshine in November:
6h and 18min - Average sunshine in December:
6h and 30min
The month with the most sunshine is June (Average sunshine: 10h and 36min).
The month with the least sunshine is November (Average sunshine: 6h and 18min).
Average sunshine days
Umatac, GU
- Average sunshine days in January:
5.4 days - Average sunshine days in February:
5.8 days - Average sunshine days in March:
6.6 days - Average sunshine days in April:
5.8 days - Average sunshine days in May:
4.3 days - Average sunshine days in June:
2.1 days
- Average sunshine days in July:
1.4 days - Average sunshine days in August:
1.6 days - Average sunshine days in September:
1.1 days - Average sunshine days in October:
1.4 days - Average sunshine days in November:
3.6 days - Average sunshine days in December:
4.7 days
The month with the most sunshine days is March (6.6 days).
The month with the least sunshine days is September (1.1 days).
Average UV index
Umatac, GU
The months with the highest UV index are January, February, March, April, May, June, July, August, October, November and December (UV index 7).
The month with the lowest UV index is September (UV index 6).
Average cloud cover
Umatac, GU
The months with the most cloud cover are January, August and October (Cloud cover 46).
The months with the least cloud cover are May and June (Cloud cover 39).
Average visibility
Umatac, GU
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
