The size of the welt indicates the strength of the reaction. If you do not react to the extract you are most likely not allergic to the substance. A mild winter often leads to a more severe pollen season. The grass season varies the most. If the spring is warmer and wetter than usual, that can provoke more grass to grow earlier, leading to a more severe season during the late spring and summer.
Rain does have benefits, as well.
It washes pollen that has already been released out of the air. Although it can be difficult to avoid pollen, there are several steps you can take to reduce your exposure. Keeping your windows closed and using air conditioning even on days that are not extremely warm can keep pollen outdoors. You can also avoid outdoor activities during the peak pollen times of day. Grass pollens are most prevalent during afternoon and early evening, while ragweed pollens are most prevalent during early midday.