I've been working with the Central England Temperature (CET) series a bit lately, and one thing I've worked out is the most recent warm and cold record for each day of the year. I'm toying around with different visualistion methods.
The one below has the daily records with diamond symbols and the monthly averages with solid lines. The 365 days of the year follow the 360 degrees of the circle. The bands are at 50 day intervals, so the closer to the centre, the more recent the record was set.
However, I still think it's a bit messy, so any suggestion on altering it or whatever else is quite welcome!