Inflation experts - how does this work?

[cakeorwine]

I know that inflation is the cost of a basket of goods compared to a year ago.
So say the basket was (hypothetically)
June 2021 - £100
June 2022 - £110

We have 10% inflation

But what about in this case. (again hypothetical)
Jan 2021 - £100
June 2021 - £105
Jan 2022 - £110
June 2022 - £105

So in January 2022 - it would be 10% compared to the year before
But in June 2022, it would be 0% compared to the year before

Goods were getting more expensive during 2021 but then went down during 2022.

Have we got 'month on month' deflation and year on year inflation?

These are just hypothetical numbers for ease of maths

In Jan 22 inflation for the year would be 10%, on June 22 it would be 0% for the last year.

The index comes out more frequently than this, but as you correctly say, the number quoted on the news tends to be the percentage change over the last year.

First example 10% yoy inflation yes

2nd example to June 22, 0% yoy inflation and between Jan and June 2022 you have deflation from Jan to June comparing on with the other, month on month figures need exact data to be able to say so would need May and June to know the 1 month change.

That would also be an unusual scenario though the second one for 2022 after 2021 inflation rise like that.

The Bank of England has information on inflation on its website

www.bankofengland.co.uk/monetary-policy/inflation