Here are the monthly temperature and precipitation departures from the long-term average by month in Illinois for 2013. After a warmer-than-average January, temperatures have been below-average in February, March, and April. Monthly precipitation has been above-average in January, February, and April, but slightly below-average in March.
This is a far cry from the first four months of 2012 which were noteworthy for being both above-average on temperatures and below-average on precipitation. See the second pair of figures for 2012.
My trees seem a bit unsure about the demise of winter. They are ever so hesitantly leafing out, and I have never seen anything like it before.
A few years ago I read a paper on a possible relationship between sunspots and tree growth, that correlated with observations I had made. Sadly I did not save a draft and have not been able to find it since. Our Sun is the quietest it has been in a century, and this low activity is expected to last for quite a spell.
We are starting to see just what influence the Sun has on our humble home.