Wednesday 25th March
Tuesday was an uninspiring day with total, continuous cloud cover resulting in no sunshine and temperatures depressed. In addition light, brief drizzle was observed at 16.40 with two narrow bands of rain passing our way in the evening at 1930 and 2015. A further shower reached our area between 05.30 and 06.30 early Wednesday. The daily rainfall total was 4.8mm that took the monthly total to 35.8mm being just 50% of my 42-year record. The maximum of 11.9C was 1.1C above average whilst the minimum of 3.8C at 06.30 early Wednesday was 1.2C abejv average.
Wednesday revealed another cloudy start to the day but after 08.00 there were signs that we might have bright or brief sunny intervals between the shower activity streaming down from the northwest. The polar air arrived last night behind the cold front that brought the cloud and rain. There will be significant wind chill today thanks to the strong wind and lower temperature, an example was a temperature of 4.4C at 08.00 whilst outside it felt more like 2.6C.
Today temperatures will be depressed, likely struggling to reach the average for March with a cold night to follow due to the polar air steam on a strong gusting west-northwest flow. As the wind drops light tonight will bring us a much colder night, close to freezing.
Thursday will see a transitory ridge of higher pressure dampen down the shower activity with temperatures still depressed. However, there are signs that as we approach the weekend temperatures will return to around average for March.
A change from lambing in my recent images to the first signs of real spring and blossom beginning to appear on trees and shrubs over the next few weeks.
Part 2 of the Met Office article on diurnal temperature range (DTR). The DTR over the past twenty-four hours was 8.1C, from 11.9C to 3.8C.
DTR varies significantly across the world. High-altitude or inland regions often see large swings between day and night temperatures due to thinner, drier air and less influence from large bodies of water. Humid or cloudy regions tend to have much smaller temperature ranges because moisture and cloud cover trap heat at night and reduce daytime heating.
What influences the size of the daily temperature range?
Several factors determine how large or small the diurnal temperature range is on any given day. At the heart of it is solar radiation: the strength and duration of sunlight directly influence the daytime maximum. Longer, sunnier days lead to stronger heating, while dull, overcast days limit how high temperatures can climb.
Humidity plays a major role too. Moist air slows both heating and cooling because water vapour retains heat. As a result, humid days often have smaller temperature ranges, whereas dry air allows for quicker warming during the day and more rapid cooling overnight. Cloud cover has a similar effect. Clouds reflect some of the Sun’s energy during the day and act as a blanket at night, keeping temperatures from falling as far. On cloudy days and nights, the temperature range is typically narrower than on clear ones.
Local geography also matters. Different surfaces store heat in different ways, which can impact both daytime and nighttime temperatures.