3mm looks like about it for today - a bit less than most days since the warm spell abruptly ended (probably had around 18mm since then - not enough, but a lot better than nothing.)
If anyone is wondering how much rain is enough to be called 'useful', it obviously depends on your soil type:
Assuming no run-off, 1" (25.4mm) of rain will only penetrate 1-2" on the heaviest clay soils, up to 15" on the sandiest, and somewhere in between for loamy soils.