Temperature differences: Why is it warmer at the coast?

As we head into autumn and winter, a notable temperature difference becomes apparent between inland and coastal areas, but why is that?

Through the spring and summer months, inland or land-locked areas are notoriously warmer than coastal areas, whilst during the autumn and winter, the opposite is true.

This is because of something called specific heat capacity, which is the amount of heat a material is capable of holding. Water has a higher specific heat capacity than land, which means that it can hold more heat.

Bodies of water take longer to heat up and cool down, so absorb all the heat through the spring and summer months, when the sun is at its strongest, and then lose that heat slower through autumn and winter, once it starts cooling down.

For land on the other hand, it heats up and cools down much quicker. So during the spring and summer months the ground quickly absorbs solar radiation, consequently also warming the layer of air above it. Whereas in winter, it quickly loses all of that heat back out to the atmosphere.

As a result, areas along the coast, or near large bodies of water, will retain that warmth thanks to the sea breeze effect. When air blows over land from the water, it warms those nearby areas, before the air then cools as it travels further inland.

Of course if the wind direction is off-shore then this is not the case however, but with our prevailing westerly winds, coastal parts of Wales and the west coasts of England, and also Ireland, will often remain a few degrees higher than areas further inland as we head into the colder months.

So, if you're looking for a less cold weekend staycation over the next few months, your best bet is to head there!