The background shading is based on records going back to 1987 [here], with values ranging from 0.5mm/day (2023) to 4mm/day (2014). So far in 2026 we're above even the 2014 value.
Torpids has never been run when the average daily rainfall for Jan/Feb has exceeded 3.5mm but has always been run (in some form) when the average is less than 1.5mm. Similary, the 'Full' Torpids has always been run when the daily average was less than 1mm but has never been run when the average was above 2.3mm. I've just drawn straight lines between these points to define the three regions.
So, on that basis, 'Full' Torpids won't happen this year since even in the absence of any more rain the average will still be above 2.3mm.
To state the obvious, just taking the Jan/Feb rainfall as a single number is a crude basis for prediction. Rain at the end of February that will have a much bigger impact on Torpids than the same amount of rain in early January, but no allowance is made for this.
