Climate and monthly weather forecastGrand Fort, Guernsey
Climate and monthly weather forecast
The climate of Grand Fort
Situated in Guernsey, Grand Fort experiences a maritime temperate climate, identified as Cfb by the Köppen climate classification - a marine west coast climate with warm summers. This translates into a year punctuated by moderate temperature ranges, coupled with consistent humidity rates and variable rainfall.The year-round average temperature is relatively steady. High temperatures can peak at 17.8°C (64°F), typically noticed in August, while the cool January evenings dip as low as 7°C (44.6°F). Not only are the temperatures moderate, but the relative humidity remains consistent, fluctuating marginally from 77% to 84% throughout the year. It keeps the air consistently moist, suggesting a significant amount of water vapor present in the atmosphere.
Grand Fort gets its share of rainfall throughout the year. The wettest months are November and December, with rainfall averaging 87mm (3.43") and 70mm (2.76") respectively. In contrast, the driest months are July and May, with rainfall dropping to a low of 26mm (1.02") and 27mm (1.06"). It is interesting to note that despite the rainfall, the average hours of sunshine a day generally remain above 3.9, even in the gloomiest of months. The longest sunlit days, however, can be expected in June and July, boasting an admirable 16.2 hours and 15.8 hours of daylight.
The best time to visit Grand Fort
To take full advantage of what Grand Fort has to offer, consider visiting in the late spring or early summer - particularly in May, June, or July. During these months, temperatures are warm enough for a variety of outdoor activities, ranging from 12.8°C (55°F) to 16.9°C (62.4°F). Importantly, these months also see the lowest average rainfall of the year, with May and July only recording rainfall of 27mm (1.06") and 26mm (1.02") respectively. Long daylight hours, from 15.4 hours to 16.2 hours, promise ample time for sightseeing. The highest UV Index is observed in July at 5, suggesting moderately intense sun exposure during peak daylight hours.The worst time to visit Grand Fort
For those keen to avoid heavier rains and cooler temperatures, it might be best to steer clear of Grand Fort from November to January. November is the wettest month with a rainfall of 87mm (3.43"), while temperatures in January sink to as low as 7°C (44.6°F). The reduced daylight hours, from 9.1 hours in November to 8.3 hours in December, also curtail outdoor activities.Spring weather in Grand Fort
From March to May, spring ushers in a gradual increase in temperature, rising from 9.8°C (49.6°F) to 12.8°C (55°F). Rainfall also sees a decreasing trend, from an average of 38mm (1.5") in March to a paltry 27mm (1.06") by May. The daylight hours progressively lengthen, offering from 11.9 hours to 15.4 hours of clear daylight.Summer weather in Grand Fort
In the summer months of June to August, Grand Fort experiences warm and pleasant temperatures, ranging from 15.2°C (59.4°F) to 17.8°C (64°F). These months also see marginal rainfall, especially July with only 26mm (1.02"). Humidity remains consistent and comfortable throughout, and daylight extends its generous reach, offering up to 16.2 hours in June.Autumn weather in Grand Fort
Autumn, ranging from September through November, is characterized by cooling temperatures and increasing rainfall. Rainfall in November peaks at 87mm (3.43"), and temperatures take a dip from 17.2°C (63°F) to 13°C (55.4°F).Winter weather in Grand Fort
December through February marks the cold winter season in Grand Fort. The temperatures flirt with the cooler end of the spectrum, dropping to 7°C (44.6°F) in February. Rainfall remains appreciable, with December and January recording 70mm (2.76") and 63mm (2.48") respectively. However, despite the shorter daylight hours, Grand Fort manages to maintain an average sunshine duration of 3.9 hours a day during these months.Weather in January
January in Grand Fort, Guernsey shows a cooler start to the year. Temperatures tend to be mild, with rainfall being a frequent occurrence, resulting in higher humidity. Wind speeds reach their highest in January at 34.1km/h (21.2mph) and gusts can spike up to 47.7km/h (29.6mph), presenting possible challenges for outdoor activities. Weather in January »Weather in February
Entering into February, a slight drop in temperature and rainfall can be observed. Weather conditions improve in Grand Fort as humidity levels decrease slightly compared to January. February is particularly distinctive for being the last month to potentially experience snowfall, though accumulation is minimal at 2mm (0.08"), making the likelihood of a snowy scene in Grand Fort rare. Weather in February »Weather in March
As spring unfolds in March, there’s a distinct change in the weather of Grand Fort. The month enjoys a significant increase in both daylight and sunshine hours, which aligns well with outdoor pursuits. Temperatures rise, rainfall dips and winds continue their decreasing trend from the previous month. Weather in March »Weather in April
April embodies the true spirit of spring in Grand Fort. The weather continues to improve and the way sunshine dominates the higher number of daylight hours become more evident. While rainfall continues to decrease, the temperature steadily rises, encouraging outdoor interpersonal activity. Weather in April »Weather in May
As summer approaches, the weather in May in Grand Fort shows a delightful transition. A further boost in sunshine hours and longer daylight hours result in glorious days, perfect for outdoor exploration. Combined with the warmth of a higher temperature, low wind speeds, and the same great visibility, May encourages numerous outdoor activities. Weather in May »Weather in June
June in Grand Fort welcomes the onset of summer and it brings along the highest average daylight hours. The outdoor weather conditions are excellent with the finest visibility, making this month even more conducive to sightseeing. Weather in June »Weather in July
Weather in July holds the apex of summer for Grand Fort with the highest temperature averages. Results in warmer days and balmy nights, making it the perfect time for beach and water activities. The month features a slight fluctuation in the weather parameters with a small decrease in rainfall and a decrease in daylight hours. Weather in July »Weather in August
August continues the warmth of July in Grand Fort while beginning to signal the close of summer. This climatic shift is noticeable with a mild increase in rainfall amounting to 41mm (1.61"), from 26mm (1.02") the previous month. Weather in August »Weather in September
As Grand Fort, Guernsey enters autumn, September makes a clear break from the summer weather. Temperature starts to descend, along with a decrease in sunlight hours making the days shorter. Despite the drop in temperature, humidity remains almost constant since August. Weather in September »Weather in October
October in Grand Fort carries full swing autumn weather with substantial changes. The most apparent is a decrease in temperature and daylight hours, indicating the approach of winter. As autumn progresses, the rainfall indicates an upward spike, registering at 58mm (2.28"). Weather in October »Weather in November
November proves to be noticeably cooler in Grand Fort, Guernsey. The proximity to winter is acknowledged by further decreases in average temperatures and daylight hours. However, November holds the year's highest level of rainfall at 87mm (3.43"), leading to an increased number of rainy days. Weather in November »Weather in December
December in Grand Fort indicates the beginning of winter with the shortest daylight hours of the year. Although temperatures continue to drop, the difference from November isn’t as pronounced as earlier transitions between months. Weather in December »Updated: Feb 9, 2024
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Throughout the year, in Grand Fort, Guernsey, there are 196.3 rainfall days, and 557mm (21.93") of precipitation is accumulated.
January is the only month when snow falls.
January is the month with the most snowfall in Grand Fort. Snow falls for 0.3 days and accumulates 2mm (0.08") of snow.
In Grand Fort, Guernsey, during the entire year, snow falls for 0.5 days and aggregates up to 2mm (0.08") of snow.
The months with the least sunshine in Grand Fort, Guernsey, are January, November and December, with an average of 3.9h of sunshine.
February brings the lowest temperatures, with an average high of 9.2°C (48.6°F) and an average low of 7°C (44.6°F).
February through December are months without snowfall in Grand Fort.
The month with the lowest UV index is February, with an average maximum UV index of 2.
June and July, with an average relative humidity of 84%, are most humid months in Grand Fort.
With an average of 16h and 12min of daylight, June has the longest days of the year.
The month with the least rainfall in Grand Fort, Guernsey, is July, when the rain falls for 12.8 days and typically collects 26mm (1.02") of precipitation.
The month with the most sunshine in Grand Fort, Guernsey, is July, with an average of 9.7h of sunshine.
The months with the highest UV index in Grand Fort are July through September, with an average maximum UV index of 5.
In Grand Fort, August is known for its average highest temperatures, reaching a high of 17.8°C (64°F) and a low of 15.8°C (60.4°F).
On Sunday, 27. October 2024, at 02:00, Daylight Saving Time ends in Grand Fort, Guernsey, and the time zone changes from BST to GMT. The next Daylight Saving Time starts on Sunday, 30. March 2025, at 01:00, and the time zone reverts from GMT to BST.
The months with the lowest humidity in Grand Fort, Guernsey, are November and December, with an average relative humidity of 77%.
November is the month with the most rainfall in Grand Fort, Guernsey. Rain falls for 22.8 days and accumulates 87mm (3.43") of precipitation.
The month with the shortest days is December, with an average of 8h and 12min of daylight.
Average temperature
Grand Fort, Guernsey
The warmest month (with the highest average high temperature) is August (17.8°C).
The month with the lowest average high temperature is February (9.2°C).
The month with the highest average low temperature is August (15.8°C).
The coldest month (with the lowest average low temperature) is February (7°C).
Average pressure
Grand Fort, Guernsey
- Average pressure in January:
1016.1mbar - Average pressure in February:
1015.2mbar - Average pressure in March:
1016.2mbar - Average pressure in April:
1015.6mbar - Average pressure in May:
1017.4mbar - Average pressure in June:
1016.9mbar
- Average pressure in July:
1016.7mbar - Average pressure in August:
1016.4mbar - Average pressure in September:
1017.9mbar - Average pressure in October:
1015.7mbar - Average pressure in November:
1011.5mbar - Average pressure in December:
1016.5mbar
The month with the highest atmospheric pressure is September (1017.9mbar).
The month with the lowest atmospheric pressure is November (1011.5mbar).
Average wind speed
Grand Fort, Guernsey
- Average wind speed in January:
34.1km/h - Average wind speed in February:
34km/h - Average wind speed in March:
30.3km/h - Average wind speed in April:
25km/h - Average wind speed in May:
23.7km/h - Average wind speed in June:
22.8km/h
- Average wind speed in July:
21.9km/h - Average wind speed in August:
22.8km/h - Average wind speed in September:
25.8km/h - Average wind speed in October:
29.1km/h - Average wind speed in November:
34.8km/h - Average wind speed in December:
36km/h
The windiest month (with the highest average wind speed) is December (36km/h).
The calmest month (with the lowest average wind speed) is July (21.9km/h).
Average humidity
Grand Fort, Guernsey
The months with the highest relative humidity are June and July (84%).
The months with the lowest relative humidity are November and December (77%).
Average rainfall
Grand Fort, Guernsey
The wettest month (with the highest rainfall) is November (87mm).
The driest month (with the least rainfall) is July (26mm).
Average rainfall days
Grand Fort, Guernsey
- Average rainfall days in January:
22 days - Average rainfall days in February:
17.7 days - Average rainfall days in March:
17 days - Average rainfall days in April:
13.3 days - Average rainfall days in May:
11.8 days - Average rainfall days in June:
11.5 days
- Average rainfall days in July:
12.8 days - Average rainfall days in August:
14 days - Average rainfall days in September:
13.5 days - Average rainfall days in October:
18.5 days - Average rainfall days in November:
22.8 days - Average rainfall days in December:
21.4 days
The month with the highest number of rainy days is November (22.8 days).
The month with the least rainy days is June (11.5 days).
Average snowfall
Grand Fort, Guernsey
The month with the highest snowfall is January (2mm).
The months with the least snowfall are February, March, April, May, June, July, August, September, October, November and December (0mm).
Average snowfall days
Grand Fort, Guernsey
- Average snowfall days in January:
0.3 days - Average snowfall days in February:
0.2 days - Average snowfall days in March:
0 days - Average snowfall days in April:
0 days - Average snowfall days in May:
0 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 days - Average snowfall days in November:
0 days - Average snowfall days in December:
0 days
The month with the highest number of snowfall days is January (0.3 days).
The months with the least snowfall days are March, April, May, June, July, August, September, October, November and December (0 days).
Average daylight / Average sunshine
Grand Fort, Guernsey
- Average daylight in January:
8h and 42min - Average daylight in February:
10h and 6min - Average daylight in March:
11h and 54min - Average daylight in April:
13h and 48min - Average daylight in May:
15h and 24min - Average daylight in June:
16h and 12min
- Average daylight in July:
15h and 48min - Average daylight in August:
14h and 24min - Average daylight in September:
12h and 36min - Average daylight in October:
10h and 48min - Average daylight in November:
9h and 6min - Average daylight in December:
8h and 12min
The month with the longest days is June (Average daylight: 16h and 12min).
The month with the shortest days is December (Average daylight: 8h and 12min).
- Average sunshine in January:
3h and 54min - Average sunshine in February:
4h and 0min - Average sunshine in March:
6h and 12min - Average sunshine in April:
9h and 6min - Average sunshine in May:
9h and 6min - Average sunshine in June:
9h and 6min
- Average sunshine in July:
9h and 42min - Average sunshine in August:
9h and 12min - Average sunshine in September:
8h and 24min - Average sunshine in October:
4h and 54min - Average sunshine in November:
3h and 54min - Average sunshine in December:
3h and 54min
The month with the most sunshine is July (Average sunshine: 9h and 42min).
The months with the least sunshine are January, November and December (Average sunshine: 3h and 54min).
Average sunshine days
Grand Fort, Guernsey
- Average sunshine days in January:
5.5 days - Average sunshine days in February:
6.9 days - Average sunshine days in March:
10.7 days - Average sunshine days in April:
14.8 days - Average sunshine days in May:
16.3 days - Average sunshine days in June:
16 days
- Average sunshine days in July:
15.4 days - Average sunshine days in August:
12.1 days - Average sunshine days in September:
13.1 days - Average sunshine days in October:
8.6 days - Average sunshine days in November:
4 days - Average sunshine days in December:
5.3 days
The month with the most sunshine days is May (16.3 days).
The month with the least sunshine days is November (4 days).
Average UV index
Grand Fort, Guernsey
The months with the highest UV index are July, August and September (UV index 5).
The month with the lowest UV index is February (UV index 2).
Average cloud cover
Grand Fort, Guernsey
The months with the most cloud cover are November and December (Cloud cover 63).
The month with the least cloud cover is July (Cloud cover 37).
Average visibility
Grand Fort, Guernsey
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (10km).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (10km).
