Scilly Climate

From what you already know about Britain’s climate you should be able to take a guess at what it is like on the Isles of Scilly.  Read on and see if you are right.

Located off the south-west tip of Cornwall, the Scilly Isles are as far south as Blog About Britain is going to go.

They are also sitting out on the edge of the Atlantic Ocean.  This means that the wind is usually pretty moist, due to blowing in across the sea.  Fortunately, the islands are low-lying, so much of the cloud blows straight across, keeping the rainfall total to a modest 880mm.  This is plenty for plants, particularly as the rain is spread evenly through the year, falling on over 15 days in every month.

Sea temperatures around the Isles of Scilly range from 10°C in winter to 16°C in summer and, as you are never too far from the sea on these tiny islands, this has a big effect on the temperature inland.

As you can see from the graph, the maximum temperature in the summer is 19°C – warm enough, but perhaps colder than you were expecting for somewhere so far south.

However, it is the winter temperature that is perhaps the most interesting.  Snow on Scilly is extremely rare with an average of 8°C throughout the winter months.

As there is rarely even a frost, plants are able to keep growing.  The gardens at Tresco Abbey contain a collection of sub-tropical plants from places such as the Mediterranean, Australia, South Africa, the Canary Islands, South America, California and Mexico.

Some of the species have spread beyond the gardens.

The mild, wet environment is also great for farming.  I’ll tell you about that next week.

Evidence for Temperature Change

Average temperatures gradually change over time, and it doesn’t need to be a big change to start to make a difference.

We hear a lot about climate change and global warming.  Why the worry?  Well a rise in global temperature, even a small one, would result in less ice, in the Arctic, Antarctic and on mountains, since more of it would melt.  That would mean more water in the sea.

More water in the sea, plus the fact that the sea would also be slightly warmer, (and when things get warmer they expand), would both contribute to making the sea level higher.

People are worried because tides will get higher and coastal areas will be in danger of flooding.  Many of the world’s biggest cities are on tidal rivers.

London has been protected by a flood barrier across the Thames since 1984.  It is raised when storms cause exceptionally high tides.  You can find out more via this link.

Our landscape contains evidence for both higher temperatures and lower temperatures in the past.  For now, we are going to focus on lower temperatures.

So if average temperatures used to be lower, we should find evidence at the coast.  Join me for a look next week.

What’s Normal?

Last week we looked at the highs and lows of record temperatures in Britain, but these extremes are balanced out by the many days of more usual temperatures.  So what is normal?

These are the average temperatures for July.  As you would probably expect, the warmest places are in the south of England.

The pattern for January is a little different.  As we saw last week, the coldest places are towards the north but away from the coast.  Coastal areas are warmed by the relatively warm sea.  This is especially true on the western side of Britain, where the current is bringing warm water from near the equator.  As you can see, the west of Scotland has the same average temperature as London.

These maps, along with the rainfall ones from Friday, give you an idea of Britain’s climate.

Climate is the average weather over a period of time.  The weather changes all the time, but climate changes much more slowly.  But it does change, as we will begin to see.  Join me again next Monday.

You already have the average rainfall map and I’ll be sending these average temperature maps out to those who’ve signed up to receive them.

Rainfall Patterns

Well I don’t know about you, but we’ve had quite a dry week.  Some weeks are like that, while others are the opposite, so rainfall measurements are usually collected over a long period of time.

This map shows typical rainfall totals for a whole year.  Find your location and use the key to see how much rain you usually get in a year, in your area.  If you are in Ireland then here’s your map.

Notice that, in both Britain and Ireland, the west (on the left) is generally wetter than the east.  The wettest areas tend to coincide with areas of high ground.

If you are signed up to receive my worksheets, check your inbox for maps and instructions related to today’s post.  If you still need to sign up, complete the form below.

How Do We Compare?

Blog About Britain is about Britain, obviously, but knowing that the maximum temperature outside my house today is likely to be about 6°C is pretty meaningless without something to compare it to.

Is 6°C hot, cold, warm, cool?

Your opinion is going to depend on the temperature where you live and your experience of other places.  If you live in Aviemore, Scotland, where the maximum temperature today is expected to be 3°C, then you might want to describe my day as warm.  If you live in St Mary’s on the Scilly Isles, where 11°C is the expected maximum temperature, then that makes my area sound rather chilly.

Today, being the 1st January, would be a good day to start a little comparison of temperatures, in different places, which is something our family did about 10 years ago.  We chose a variety of places around the world and checked the maximum daytime temperature regularly, for a whole year, using online data.

We did it once a week but once a month would still give you some interesting comparisons.

Think you will forget?  Like Blog About Britain on Facebook and make sure that you are set to receive notifications from the page.  I’ll post a reminder for the first of each month in 2018.

If you’ve signed up to receive worksheets from Blog About Britain then I’ll be emailing you with more detail about what we did, including guidance on how to choose places to be sure of some interesting results.  If you’ve not yet signed up you can do so below.

Happy New Year!