You can look up pollen load in weather forecasts to get an empiric answer and it's useful if you plan to spend a lot of time outside during certain days. And yes it varies from year to year.
Unfortunately global climate change generally makes it worse as plants start to blossom earlier and longer with increased temperatures.
Nevertheless keep in mind that others things affect your reaction too namely your general health state, medication, nutrition, time spent outside/inside, stress, how often and when you open your windows, wash your hair or change clothes or whether you own a pet. Whether you dry your washed clothes outside, if you're a smoker and whether you live rural or urban.
Mayhaps some factors have changed for you? During allergy season I try to adapt my behavior as much as possible.