Average Weather at Belfast International Airport United Kingdom
At Belfast International Airport, the summers are cool; the winters are long, very cold, wet, and windy; and it is mostly cloudy year round. Over the course of the year, the temperature typically varies from 36°F to 66°F and is rarely below 28°F or above 73°F.
Based on the tourism score, the best time of year to visit Belfast International Airport for warm-weather activities is from late June to late August.
The warm season lasts for 3.1 months, from June 7 to September 12, with an average daily high temperature above 61°F. The hottest day of the year is July 26, with an average high of 66°F and low of 53°F.
The cool season lasts for 4.0 months, from November 18 to March 17, with an average daily high temperature below 49°F. The coldest day of the year is February 17, with an average low of 36°F and high of 45°F.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature
At Belfast International Airport, the average percentage of the sky covered by clouds experiences mild seasonal variation over the course of the year.
The clearer part of the year at Belfast International Airport begins around April 3 and lasts for 6.4 months, ending around October 16. On July 18, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 49% of the time, and overcast or mostly cloudy 51% of the time.
The cloudier part of the year begins around October 16 and lasts for 5.6 months, ending around April 3. On January 27, the cloudiest day of the year, the sky is overcast or mostly cloudy 70% of the time, and clear, mostly clear, or partly cloudy 30% of the time.
Cloud Cover Categories
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days at Belfast International Airport varies throughout the year.
The wetter season lasts 6.0 months, from August 5 to February 5, with a greater than 37% chance of a given day being a wet day. The chance of a wet day peaks at 45% on January 3.
The drier season lasts 6.0 months, from February 5 to August 5. The smallest chance of a wet day is 28% on April 21.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 44% on January 3.
Daily Chance of Precipitation
To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Belfast International Airport experiences some seasonal variation in monthly rainfall.
Rain falls throughout the year at Belfast International Airport. The most rain falls during the 31 days centered around October 25, with an average total accumulation of 3.3 inches.
The least rain falls around April 30, with an average total accumulation of 1.9 inches.
Average Monthly Rainfall
The length of the day at Belfast International Airport varies extremely over the course of the year. In 2018, the shortest day is December 21, with 7 hours, 14 minutes of daylight; the longest day is June 21, with 17 hours, 18 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 4:47 AM on June 18, and the latest sunrise is 4 hours, 1 minute later at 8:47 AM on December 29. The earliest sunset is at 3:58 PM on December 14, and the latest sunset is 6 hours, 8 minutes later at 10:05 PM on June 24.
Daylight saving time (DST) is observed at Belfast International Airport during 2018, starting in the spring on March 25, lasting 7.1 months, and ending in the fall on October 28.
Sunrise & Sunset with Twilight and Daylight Saving Time
The perceived humidity level at Belfast International Airport, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, remaining a virtually constant 0% throughout.
Humidity Comfort Levels
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The average hourly wind speed at Belfast International Airport experiences significant seasonal variation over the course of the year.
The windier part of the year lasts for 5.8 months, from October 7 to April 1, with average wind speeds of more than 13.4 miles per hour. The windiest day of the year is January 6, with an average hourly wind speed of 16.2 miles per hour.
The calmer time of year lasts for 6.2 months, from April 1 to October 7. The calmest day of the year is July 27, with an average hourly wind speed of 10.7 miles per hour.
Average Wind Speed
The predominant average hourly wind direction at Belfast International Airport varies throughout the year.
The wind is most often from the west for 3.2 months, from January 14 to April 20; for 3.9 months, from June 1 to September 28; and for 1.5 months, from October 29 to December 14, with a peak percentage of 40% on August 17. The wind is most often from the south for 1.4 months, from April 20 to June 1; for 1.0 months, from September 28 to October 29; and for 1.0 months, from December 14 to January 14, with a peak percentage of 37% on October 12.
Belfast International Airport is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.
The average water temperature experiences some seasonal variation over the course of the year.
The time of year with warmer water lasts for 3.7 months, from July 8 to October 30, with an average temperature above 55°F. The day of the year with the warmest water is August 30, with an average temperature of 57°F.
The time of year with cooler water lasts for 3.5 months, from January 16 to May 2, with an average temperature below 48°F. The day of the year with the coolest water is March 12, with an average temperature of 45°F.
Average Water Temperature
Best Time of Year to Visit
To characterize how pleasant the weather is at Belfast International Airport throughout the year, we compute two travel scores.
The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit Belfast International Airport for general outdoor tourist activities is from late June to late August, with a peak score in the third week of July.
The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Belfast International Airport for hot-weather activities is from early July to early August, with a peak score in the third week of July.
For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.
Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.
Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.
Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.
Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.
The growing season at Belfast International Airport typically lasts for 6.9 months (211 days), from around April 15 to around November 12, rarely starting before March 16 or after May 10, and rarely ending before October 19 or after December 8.
Time Spent in Various Temperature Bands and the Growing Season
Based on growing degree days alone, the first spring blooms at Belfast International Airport should appear around May 16, only rarely appearing before May 5 or after June 1.
Growing Degree Days
The average daily incident shortwave solar energy experiences extreme seasonal variation over the course of the year.
The brighter period of the year lasts for 3.5 months, from April 29 to August 12, with an average daily incident shortwave energy per square meter above 4.7 kWh. The brightest day of the year is June 14, with an average of 5.8 kWh.
The darker period of the year lasts for 4.0 months, from October 23 to February 22, with an average daily incident shortwave energy per square meter below 1.5 kWh. The darkest day of the year is December 22, with an average of 0.4 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Belfast International Airport are 54.658 deg latitude, -6.216 deg longitude, and 210 ft elevation.
The topography within 2 miles of Belfast International Airport contains only modest variations in elevation, with a maximum elevation change of 312 feet and an average elevation above sea level of 227 feet. Within 10 miles contains only modest variations in elevation (1,522 feet). Within 50 miles contains very significant variations in elevation (2,799 feet).
The area within 2 miles of Belfast International Airport is covered by grassland (77%) and artificial surfaces (16%), within 10 miles by grassland (64%) and water (24%), and within 50 miles by grassland (47%) and water (37%).
This report illustrates the typical weather at Belfast International Airport, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
Belfast International Airport has a weather station that reported reliably enough during the analysis period that we have included it in our network. When available, historical temperature and dew point measurements are taken directly from this weather station. These records are obtained from NOAA's Integrated Surface Hourly data set, falling back on ICAO METAR records as required.
In the case of missing or erroneous measurements from this station, we fall back on records from nearby stations, adjusted according to typical seasonal and diurnal intra-station differences. For a given day of the year and hour of the day, the fallback station is selected to minimize the prediction error over the years for which there are measurements for both stations.
The stations on which we may fall back include but are not limited to Machrihanish Meteorlogical Station, Campbeltown Airport, Islay Airport, Dublin Airport, West Freugh, Casement Aerodrome, Isle Of Man / Ronaldsway Airport, and Prestwick Airport.
Time zones for aiports and weather stations are provided by AskGeo.com .