A few years ago I bought one of those diaries that weren't specific to a year. They had a date like March 15th but no day of the week or year. The plan was that I would make notes in there of when I observed stuff in nature like the first time I really noticed the leaves turning or the first really warm day. Then over the years I could leaf through and look at the dates and see what flowers were out and what was around, especially the wild flowers which sometimes have a shorter season. I have absolutely no idea where that is but I may dig it out or create an electronic alternative.
I remembered that this morning as I noticed forsythia starting to bloom for the first time this morning. Even without the diary I knew that it was around a month later than it was last year. This time last year we were knee deep in dandelions and early blossom. At the moment it is looking far more like January than March through my window. Of course, this time last year many parts of the UK were under drought warnings. Now we are all under flood warnings.
It does beg the question - if I am describing a natural scene in a temperate environment, how do I know what is going to be there? I am currently writing about June, at the time when Wimbledon normally starts. A huge, overgrown privet that is now tree sized is normally in bloom at this time and the scent is very distinctive when I go and fetch my father's paper. Last year it was almost a month late as the awful wet and gloomy weather had begun.
I am currently relying on wikipedia.