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Contents
- The climate of Belfast
- The Best Time to Visit Belfast
- The Worst Time to Visit Belfast
- Spring Weather in Belfast
- Summer Weather in Belfast
- Autumn Weather in Belfast
- Winter Weather in Belfast
- Weather in January
- Weather in February
- Weather in March
- Weather in April
- Weather in May
- Weather in June
- Weather in July
- Weather in August
- Weather in September
- Weather in October
- Weather in November
- Weather in December
- Frequently asked questions
- Average temperature
- Average pressure
- Average wind speed
- Average humidity
- Average rainfall
- Average rainfall days
- Average snowfall
- Average snowfall days
- Average sea temperature
- Average daylight
- Average sunshine
- Average sunshine days
- Average UV index
- Average cloud cover
- Average visibility
Climate and monthly weather forecast
The climate of Belfast
Belfast, Maine, resides under the Köppen climate classification as 'Dfb,' which stands for a humid continental climate with summers that tend toward warmth rather than heat. Belfast's geographical position on the eastern seaboard of the United States, just off the coast of the Atlantic Ocean, contributes to its varying yet temperate climatic conditions.
An examination of Belfast's climatological parameters indicates distinguishable seasons throughout the year. Annual average temperatures fluctuate from low temperatures of around 17°F (-8.3°C) in the colder months to high temperatures peaking at around 74°F (23.3°C) during the summer. The monthly average relative humidity varies quite a bit, with the drier months having around 77% humidity and the wetter months reaching up to 83%.
Rainfall in Belfast is fairly consistent, averaging between 1.5 and 2.7" (69mm) per month; but interestingly, December often sees the highest precipitation, measuring 2.72" (69mm). In comparison, snowfall is present only from October to April, with most heavy snowfalls occurring between December and February, up to 4.57" (116mm). The wind speed throughout the year ranges from 6 to 10mph (16.1km/h), while the visibility mostly stays at 6 miles, indicating a fairly steady wind condition.
An examination of Belfast's climatological parameters indicates distinguishable seasons throughout the year. Annual average temperatures fluctuate from low temperatures of around 17°F (-8.3°C) in the colder months to high temperatures peaking at around 74°F (23.3°C) during the summer. The monthly average relative humidity varies quite a bit, with the drier months having around 77% humidity and the wetter months reaching up to 83%.
Rainfall in Belfast is fairly consistent, averaging between 1.5 and 2.7" (69mm) per month; but interestingly, December often sees the highest precipitation, measuring 2.72" (69mm). In comparison, snowfall is present only from October to April, with most heavy snowfalls occurring between December and February, up to 4.57" (116mm). The wind speed throughout the year ranges from 6 to 10mph (16.1km/h), while the visibility mostly stays at 6 miles, indicating a fairly steady wind condition.
The Best Time to Visit Belfast
Summer months (June through August) are considered the best time for a visit to Belfast. During these months, temperatures rise to between 66.7°F (19.3°C) and 74°F (23.3°C), with the warmest month typically being July. Humidity stands at an average of 82%, ensuring a bearable warmth. Sea temperatures also peak, reaching as high as 60.4°F (15.8°C) in August. Moreover, the amount of sunshine also increases during these months, providing great conditions for outdoor activities.
The Worst Time to Visit Belfast
The colder months of winter (December to February) generally are deemed as less appealing for tourists. The temperature can drop to as low as 16.2°F (-8.8°C). Snowfall sees a significant increase over these months with up to 4.57" (116mm) annually. Visiting Belfast during this time requires adequate preparation for cold weather.
Spring Weather in Belfast
Spring arrives in Belfast between March and May. During this time, temperatures gradually rise from 37°F (2.8°C) to about 60°F (15.6°C). This season also brings an increase in daily sunshine hours, which typically go from 5.1 to 7.6 hours per day. Rainfall remains moderate with between 1.57" (40mm) and 2.05" (52mm), while the relative humidity hovers around 79% to 80%.
Summer Weather in Belfast
The summer months of June through August are generally warm and mildly humid in Belfast. Average high temperatures hover between 66.7°F (19.3°C) and 74°F (23.3°C), with temperatures rarely exceeding 73.9°F (23.3°C). Summer also brings the least amount of cloud cover, with averages of 41-47%. The overall pressure stays between 29.91inHg (1012.9mbar) and 29.93inHg (1013.5mbar), common for warm seasons.
Autumn Weather in Belfast
In Fall, September to November, temperatures cool down to a range between 67.1°F (19.5°C) and 44.1°F (6.7°C). The amount of sunshine hours also decreases as the season progresses from 8.1 to 5 hours per day. Rainfall witnesses an increase, with averages around 1.46" (37mm) to 2.32" (59mm). Relative humidity marginally drops to 77-80%.
Winter Weather in Belfast
Winter weather in Belfast, which covers December to February, ushers in the coldest temperatures of the year. High temperatures generally range from 28.4°F (-2°C) to 37°F (2.8°C), with low temperatures at times reaching 16.2°F (-8.8°C). Snowfall sees the most considerable increase during this season, reaching as high as 4.57" (116mm) in December. Average relative humidity reaches approximately 79%, indicating a relatively damp winter.
Weather in January
Belfast, Maine ushers in the New Year with a winter wonderland ambiance. The weather during this season is typically cold, living up to the reputation of New England's harshest winter month. Weather conditions range from ample snowfall to freezing temperatures. Weather in January »
Weather in February
As the state transitions from January to February, Maine's winter season continues to be in full swing. Nonetheless, the weather pattern indicates a slight increase in temperatures compared to the previous month. Residents note a slight drop in snowfall during February, recording 3.58" (91mm), frequently leading to calmer winter days. Weather in February »
Weather in March
March arrives with subtle signs of spring despite maintaining the cold grip of winter. Weather conditions shift throughout the month, with a notable decline in snowfall and slight warming of temperatures compared to February. Snowfall dwindles to a scant 2.76" (70mm), hinting at the potential transition to spring. Weather in March »
Weather in April
April symbolizes the onset of spring in Belfast, Maine. Lighter jackets replace bulky winter clothing as temperatures continue to rise, complementing the longer days with a healthy amount of sunlight. Notably, rainfall inches up to 2.64" (67mm) in April, from 1.57" (40mm) in March, signaling the shift from snowflakes to raindrops. Weather in April »
Weather in May
May is an official declaration of Spring, and it brings along pleasant weather, green landscapes, and abundant daylight. Comparing the conditions of the previous month, May showcases reduced rainfall and a sudden switch from the sporadic April showers. Weather in May »
Weather in June
In June, Belfast experiences summer in its most refined form. It's a period of endurance for the locals as temperatures continue to rise following May's pattern. Daylight is predictably plentiful in June, reaching a zenith close to the summer solstice. Weather in June »
Weather in July
July is the most scorching month in Belfast, Maine, when summer is at its peak. Weather conditions can switch from warm, sunny days to occasional summer showers. Despite the prevalent heat, it is the month with the hottest temperatures, peaking at a sweltering 73.9°F (23.3°C). Weather in July »
Weather in August
As summer's end draws near in Belfast, August brings slight changes in the weather conditions. Unlike July, average temperatures tend to take a slight dip, indicating autumn's impending arrival. Interestingly, snowfall remains non-existent, maintaining the norm of a snow-free summer season. Weather in August »
Weather in September
In September, Belfast, Maine, transitions from the warm temperatures of late summer to the cool early onset of fall. The weather undergoes marked changes, rain being a constant pattern across this month. Equally notable is the drop in high temperatures, from 73.9°F (23.3°C) in August to a more relaxed 67.1°F (19.5°C). Weather in September »
Weather in October
October brings noticeable changes in Belfast's weather, with locals preparing for the colder months ahead. Generally, the weather becomes less predictable, with bright, sunny days abruptly changing into cold and overcast conditions. Weather in October »
Weather in November
With the arrival of November, Belfast braces itself for the advent of another winter season. The weather in November offers a significant transformation from the milder climates of October. There's an uptick in snowfall from zero in the past months to an inch in November -- a surefire acknowledgment of winter’s close arrival. Weather in November »
Weather in December
Winter makes its full-fledged entrance in Belfast during December. The weather becomes harsher, with cold temperatures and an increased amount of snowfall when compared to November. The month reaches its highest level of snowfall within the year - a significant 2.28" (58mm). Weather in December »
Updated: Aug 10, 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
What time of the year is the coldest?
Belfast's January weather, marked by an average high temperature of 28.4°F (-2°C) and an average low temperature of 16.2°F (-8.8°C), is the coldest in the year.
How many days does it rain?
In Belfast, during the entire year, the rain falls for 141.1 days and collects up to 24.29" (617mm) of precipitation.
When does it snow?
Months with snowfall are January through May, October through December.
What is the snowiest month?
January is the month with the most snowfall. Snow falls for 10.1 days and accumulates 4.57" (116mm) of snow.
How many days does it snow?
Throughout the year, there are 44.3 snowfall days, and 16.81" (427mm) of snow is accumulated.
When is the lowest UV index?
The months with the lowest UV index are January through March, November and December, with an average maximum UV index of 2.
What are the most humid months?
February and July, with an average relative humidity of 83%, are most humid months.
What is the month with the least sunshine?
February has the least sunshine of the year, with an average of 4.3h of sunshine.
When is the ocean coldest?
March is the month with the coldest seawater, with an average ocean temperature of 37.9°F (3.3°C).
When is Daylight Saving Time (DST) in Belfast?
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from EST to EDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from EDT to EST.
When it does not snow?
In Belfast, snow does not fall in June through September.
When are the longest days?
With an average of 15h and 30min of daylight, June has the longest days of the year.
What is the month with the highest UV index?
June through August, with an average maximum UV index of 5, are months with the highest UV index.
What time of the year is the hottest?
July and August are the warmest months in Belfast, with an average high-temperature of 73.9°F (23.3°C).
What is the driest month?
July and September are months with the least rain when the rain falls for 14.5 days and typically aggregates up to 1.46" (37mm) of rain.
What is the month with the warmest ocean?
With an average ocean temperature of 60.4°F (15.8°C), August is the month with the warmest seawater.
What month has the most sunshine?
August has the most sunshine of the year, with an average of 9.9h of sunshine.
What is the least humid month?
The least humid month is November, with an average relative humidity of 77%.
What is the rainiest month in Belfast?
December is the month with the most rainfall in Belfast. Rain falls for 10.1 days and accumulates 2.72" (69mm) of precipitation.
What is the month with the shortest days?
With an average of 8h and 54min of daylight, December has the shortest days of the year.
Average temperature
Belfast, ME
The warmest months (with the highest average high temperature) are July and August (73.9°F).
The month with the lowest average high temperature is January (28.4°F).
The month with the highest average low temperature is July (57.7°F).
The coldest month (with the lowest average low temperature) is January (16.2°F).
Average pressure
Belfast, ME
- Average pressure in January:
29.96"Hg - Average pressure in February:
29.95"Hg - Average pressure in March:
30"Hg - Average pressure in April:
29.95"Hg - Average pressure in May:
29.99"Hg - Average pressure in June:
29.91"Hg
- Average pressure in July:
29.93"Hg - Average pressure in August:
29.96"Hg - Average pressure in September:
30.04"Hg - Average pressure in October:
29.99"Hg - Average pressure in November:
30.03"Hg - Average pressure in December:
30"Hg
The month with the highest atmospheric pressure is September (30.04"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed
Belfast, ME
- Average wind speed in January:
9.9mph - Average wind speed in February:
10mph - Average wind speed in March:
10.1mph - Average wind speed in April:
9.1mph - Average wind speed in May:
7.6mph - Average wind speed in June:
7mph
- Average wind speed in July:
6mph - Average wind speed in August:
6mph - Average wind speed in September:
6.8mph - Average wind speed in October:
8.5mph - Average wind speed in November:
9.1mph - Average wind speed in December:
9.6mph
The windiest month (with the highest average wind speed) is March (10.1mph).
The calmest months (with the lowest average wind speed) are July and August (6mph).
Average humidity
Belfast, ME
The months with the highest relative humidity are February and July (83%).
The month with the lowest relative humidity is November (77%).
Average rainfall
Belfast, ME
- Average rainfall in January:
1.93" - Average rainfall in February:
1.65" - Average rainfall in March:
1.57" - Average rainfall in April:
2.64" - Average rainfall in May:
2.05" - Average rainfall in June:
2.09"
- Average rainfall in July:
1.46" - Average rainfall in August:
1.85" - Average rainfall in September:
1.46" - Average rainfall in October:
2.56" - Average rainfall in November:
2.32" - Average rainfall in December:
2.72"
The wettest month (with the highest rainfall) is December (2.72").
The driest months (with the least rainfall) are July and September (1.46").
Average rainfall days
Belfast, ME
- Average rainfall days in January:
7.3 days - Average rainfall days in February:
7.1 days - Average rainfall days in March:
10.1 days - Average rainfall days in April:
15 days - Average rainfall days in May:
15.3 days - Average rainfall days in June:
14.8 days
- Average rainfall days in July:
14.5 days - Average rainfall days in August:
13 days - Average rainfall days in September:
10.2 days - Average rainfall days in October:
13.3 days - Average rainfall days in November:
10.4 days - Average rainfall days in December:
10.1 days
The month with the highest number of rainy days is May (15.3 days).
The month with the least rainy days is February (7.1 days).
Average snowfall
Belfast, ME
- Average snowfall in January:
4.57" - Average snowfall in February:
3.58" - Average snowfall in March:
2.76" - Average snowfall in April:
2.17" - Average snowfall in May:
0.35" - Average snowfall in June:
0"
The month with the highest snowfall is January (4.57").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days
Belfast, ME
- Average snowfall days in January:
10.1 days - Average snowfall days in February:
10 days - Average snowfall days in March:
9 days - Average snowfall days in April:
2.9 days - Average snowfall days in May:
0.1 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
0.1 days - Average snowfall days in November:
3.2 days - Average snowfall days in December:
8.9 days
The month with the highest number of snowfall days is January (10.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average sea temperature
Belfast, ME
The best month for swimming (with the highest average sea temperature) is August (60.4°F).
The coldest month (with the lowest average sea temperature) is March (37.8°F).
Average daylight / Average sunshine
Belfast, ME
- Average daylight in January:
9h and 2min - Average daylight in February:
10h and 3min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 3min - Average daylight in May:
14h and 5min - Average daylight in June:
15h and 3min
- Average daylight in July:
15h and 1min - Average daylight in August:
14h and 0min - Average daylight in September:
12h and 3min - Average daylight in October:
11h and 0min - Average daylight in November:
9h and 4min - Average daylight in December:
8h and 5min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in January:
4h and 4min - Average sunshine in February:
4h and 2min - Average sunshine in March:
5h and 1min - Average sunshine in April:
7h and 1min - Average sunshine in May:
7h and 4min - Average sunshine in June:
8h and 2min
- Average sunshine in July:
9h and 2min - Average sunshine in August:
9h and 5min - Average sunshine in September:
8h and 1min - Average sunshine in October:
6h and 0min - Average sunshine in November:
5h and 0min - Average sunshine in December:
4h and 2min
The month with the most sunshine is August (Average sunshine: 9h and 54min).
The month with the least sunshine is February (Average sunshine: 4h and 18min).
Average sunshine days
Belfast, ME
- Average sunshine days in January:
16.9 days - Average sunshine days in February:
13.3 days - Average sunshine days in March:
14.5 days - Average sunshine days in April:
11.7 days - Average sunshine days in May:
13.7 days - Average sunshine days in June:
13.6 days
- Average sunshine days in July:
14.7 days - Average sunshine days in August:
15.8 days - Average sunshine days in September:
17.9 days - Average sunshine days in October:
16.1 days - Average sunshine days in November:
16.6 days - Average sunshine days in December:
14.5 days
The month with the most sunshine days is September (17.9 days).
The month with the least sunshine days is April (11.7 days).
Average UV index
Belfast, ME
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover
Belfast, ME
The month with the most cloud cover is March (Cloud cover 55).
The months with the least cloud cover are August and September (Cloud cover 37).
Average visibility
Belfast, ME
The months with the highest visibility are January, February, March, April, October, November and December (6mi).
The months with the lowest visibility are May, June, July, August and September (5mi).