Weather has a massive impact on day-to-day life in Ireland. However, what drives the weather and climate we experience in this country? In this episode, we will be answering the question ‘What Causes Ireland’s Weather?’ with Met Éireann meteorologist and forecaster Pat Clarke. Firstly, why do we have weather at all? We will start with the underlying global processes and then narrow it down to Ireland. How does the shape, rotation and axis of the earth affect our climate? What is ‘air pressure’? Why do rainforests and deserts appear in similar latitude bands around the globe? Why does Ireland often have low pressure while other areas have high pressure?  How does what’s happening in the atmosphere five to ten kilometres above our heads affect our weather at the surface? What is the jet stream and why is it stronger in the winter than the summer? What is the polar front and what side of it do we want to be on? Why do we generally get our most severe storms in the autumn and winter. Ireland is at the same latitude as Edmonton in Canada, Alaska in the U.S. and Moscow, but why do we not have similar climate extremes? For example, Edmonton in Canada is at the same latitude as Dublin, however Edmonton’s average minimum temperature in January is -15°C while in Dublin it is +2.4°C. How does the Atlantic Ocean moderate our climate?  What is an airmass? How does it form and how much does the airmass currently over us determine the kind of weather we can expect? We close out the episode with the Met Éireann choir – The Isobars – and their rendition of Raindrops Keep Falling on my Head.