Even after a relatively cool August, 2017 so far is still the sixth warmest to date (24th of August) since 1772 in Central England. As you can see in the table (fig 2), the mean temperature for 2017 so far is 11.09°C, which is +1.41°C above the 1961-1990 long-term average. For quite a while 2017 was the second warmest year and then August happened. 2014 is the year to beat though, because even though it’s currently only third in the table, it’s the warmest year on record, and for 2017 to catch it, the next four months will have to have a combined mean anomaly in excess of +1.6°C. That sounds a steep challenge, but it’s perfectly possible, after all 2014 has already done just that.
The problem of calculating just exactly what the anomaly for the next four months should be if 2017 is to beat 2014 is quite a challenge. I reckon a bit of calculus is required to do it, but any memory of that subject has long since disappeared from my memory. I could do it by trial and error using some code but I’ll leave it for a rainy day before I have a go.