The lowest average daily sun hours in the United Kingdom typically occur in January and December. The highest daily sun hours recorded since 2015 was in May 2020, at an average of 9.7 hours per day. In comparison, May 2024 saw 5.6 hours of daily sunshine. High levels of monthly sunlight in 2018 Since 2014, the pattern of total monthly hours of sunlight remained relatively similar up until 2018. That year there was a noticeable increase in sunlight hours in May, June and July – with May recording 241 hours of sunlight. The following year the pattern returned to normal, but a significant increase was again recorded in 2020. Annual sun hours The average annual number of daily sun hours in the UK has remained above four hours per day since 2001, but has not increased above five. Daily sun hours were highest in 2003 at 4.9 hours per day. The following years saw sun hours remain at a similar level, until figures increased again to 4.9 hours in 2022.

The total number of sunshine hours recorded in the United Kingdom in 2024 was over *****. This was a decrease from the previous year, which had ***** sunshine hours. Since 1930, the highest number of sunshine hours recorded in a year in the UK occurred in 1995, at *****.

The amount of monthly hours of sunshine in England follows a similar pattern each year, with the longest durations occurring in Spring and Summer. During the period in consideration, the highest amount of monthly sunshine hours was recorded in May 2020, at over *** hours. This was more hours of sunlight than the UK average. Overcast and rainyIn addition to low periods of sunshine, England is also susceptible to precipitation. Between 2015 and 2023, the greatest number of days in which more than 1mm of rain fell was **** days in March of the latter year. The driest month was May 2020, with just *** rain days. Europe’s gloomiest and sunniest citiesThe United Kingdom has some of Europe's cloudiest cities, such as Glasgow, London and Manchester. On the other hand, most of Europe’s sunniest cities are located in Spain, with Alicante taking the lead at *** hours of monthly average sunshine.

The total monthly hours of sunlight in the UK follow a similar pattern each year. May typically has the highest monthly hours of sunshine, peaking at nearly 267 hours in 2020. Unsurprisingly, the lowest hours of sunlight occur at the end of each year.Little sunshine throughout the dayThe average annual number of daily sun hours has seen little change since the turn of the century, with the lowest average number being recorded in 2012 at 4 hours and the highest average being 4.9 in 2003 and 2022. Instruments such as the Campbell-Stokes sunshine recorder are used to measure sunshine duration. However, more modern equipment is now being used as the Campbell-Stokes recorder overestimates sunshine duration. England gets the most sunshineAlthough sunshine isn't the most common sight throughout the United Kingdom, on average England receives the most monthly hours. In recent years, the longest monthly duration of sunlight was recorded in May 2020, at an average of 267 hours. In comparison, Scotland received just 215 hours of sunshine in the same month.

Since the turn of the century there has been little change in the average daily sunshine hours in the United Kingdom. In 2024, an average of 3.8 daily sun hours was recorded. This year saw the lowest amount of daily sunlight during the period in consideration, while 2003 and 2022 saw some of the highest values, with 4.9 hours of daily sunlight. Summer sun Unsurprisingly it is the spring and summer months that receive the most daily sunshine hours. The longest duration was recorded in 2020, when the average daily sunshine in the second quarter reached 7.9 hours. In 2023, the second quarter of the year had an average of seven daily sun hours. In comparison, that same year's first and fourth quarters recorded just 2.7 and 2.1 hours of daily sunshine, respectively. Historical sunshine In 1930, the average annual sunshine hours amounted to 1,290 hours. Sunlight has traditionally been recorded using a Campbell-Stokes sunshine recorder, which was developed in the late 19th century. However, measurements from this instrument can overestimate sunshine duration. Whilst still often used at non automated climate stations, more accurate modern sunshine sensors are in use these days at automated stations.

Context

Simple time series data for weather prediction time series projects.

Content

The data contains the following information from the UK Met Office location at London Heathrow Airport. The data runs from Jan 1948 to Oct 2020 and includes the following monthly data fields:

• yyyy = Year
• mm = Month
• tmax = Maximum temperature (Celsius)
• tmin = Minimum temperature (Celsius)
• af = Count of Air Frost days in the given month
• rain = Total rainfall (mm)
• sun = Sunshine duration (hrs)

Acknowledgements

Provided by the UK Met Office: https://www.metoffice.gov.uk/research/climate/maps-and-data/historic-station-data Available under Open Government Licence: http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/

Example code

The following Python code will load into a Pandas DataFrame:

colspecs = [(3, 7), (9,11),(14,18),(22,26),(32,34),(37,42),(45,50)] data = pd.read_fwf('../input/heathrow-weather-data/heathrowdata.txt',colspecs=colspecs)

The following will remove the first few lines of text

data = data[3:].reset_index(drop=True) data.columns = data.iloc[1] data = data[3:].reset_index(drop=True)

The highest average temperature recorded in 2024 until November was in August, at 16.8 degrees Celsius. Since 2015, the highest average daily temperature in the UK was registered in July 2018, at 18.7 degrees Celsius. The summer of 2018 was the joint hottest since institutions began recording temperatures in 1910. One noticeable anomaly during this period was in December 2015, when the average daily temperature reached 9.5 degrees Celsius. This month also experienced the highest monthly rainfall in the UK since before 2014, with England, Wales, and Scotland suffering widespread flooding. Daily hours of sunshine Unsurprisingly, the heat wave that spread across the British Isles in 2018 was the result of particularly sunny weather. July 2018 saw an average of 8.7 daily sun hours in the United Kingdom. This was more hours of sun than was recorded in July 2024, which only saw 5.8 hours of sun. Temperatures are on the rise Since the 1960s, there has been an increase in regional temperatures across the UK. Between 1961 and 1990, temperatures in England averaged nine degrees Celsius, and from 2013 to 2022, average temperatures in the country had increased to 10.3 degrees Celsius. Due to its relatively southern location, England continues to rank as the warmest country in the UK.