Very low humidity all afternoon here (Stratfield Mortimer, on the
Berkshire/Hampshire border SW of Reading) - hourly means below 30%
12-16h, min just under 20% at 1352 UTC.

This is the lowest on my 13 year AWS record apart from the 19% recorded
on 18 June 2000. The dew point fell below 0C for a few minutes near the
lowest point.

The lowest readings were confirmed by two other adjacent and
independent sensors; the sensor itself (Vaisala HMP45C, in my Stevenson
screen) was calibrated only six weeks ago.